GB2615229A

GB2615229A - Sail equipped with sail drag enhancement member, sail module, and drag enhancement member

Info

Publication number: GB2615229A
Application number: GB2305875.3A
Authority: GB
Inventors: Mark Atkinson Gregory
Original assignee: ECO MARINE POWER CO Ltd
Current assignee: ECO MARINE POWER CO Ltd
Priority date: 2020-10-22
Filing date: 2021-10-22
Publication date: 2023-08-02
Also published as: JPWO2022085794A1; GB202305875D0; WO2022085794A1

Abstract

The present invention provides a sail that is able to enhance drag force and that can be stored in a variety of modes.　The present invention pertains to a sail that comprises a sail body and a sail drag enhancement member which is mounted to an edge or a surface of the sail body, and that is configured not to create any gap or a significant gap between the edge or the surface of the sail body and the sail drag enhancement member.

Description

[Document Name] Description

[Title of Invention] SAIL EQUIPPED WITH SAIL DRAG ENHANCEMENT MEMBER, SAIL MODULE, AND DRAG ENHANCEMENT MEMBER

[Technical Field]

[0001] The present invention relates to a sail having a sail drag increasing member for increasing drag particularly when used as a sail of a ship, a sail module and a drag increasing member attached to a ship as a standalone device.

[Background Art] [0002]

Recently, as a means to lower fuel consumption and also to reduce harmful airborne emissions and the reduction of greenhouse gasses, considerable attention has been given to an auxiliary propulsion force generating device that makes use of a sail mounted on a powered ship or an auxiliary propulsion force generating device that makes use of wind on a powered ship.

[0003] The auxiliary propulsion force generating device that makes O ose of a sail or the auxiliary propulsion force generating device Nthat makes use of wind can be served to effectively function as a supplementary source of propulsive power, thereby reducing (C)propulsive power.

CD [0004] As the auxiliary propulsion force generating device that COmakes use of a sail, there has been known a sail for a ship disclosed I-inpatent literature 1 and patent literature 2. In this auxiliary propulsion force generating device, with the use of a square sail which can generate a high lift, wind power which is a natural energy can be effectively used so that fuel consumption can be reduced and energy saving and the reduction of emission of CO_ gas can be realized.

[0005] As shown in Fig. 28A and Fig. 28B, a square sail 2010 described in patent literature 1 includes a sail body 2011a, reinforcing portions 2011b, and a mast 2012. Further, slats 2015 are provided to both side edge portions of the sail body 2011a. The slats 2015 are respectively, as shown in Fig. 28A and Fig. 28B, formed of a rectangular arcuate wing or the like, and a large gap S is formed between the slat 2015 and the sail body 2011a at both side edges. Such slats 2015 are provided as a high lift generating device. By forming the gap S between the sail body 2011a and the slat 2015, the slat 2015 performs a function of allowing an airflow to flow from a lower surface (concave surface) side toward an upper surface (convex surface) side so that a maximum lift can be acquired.

[Citation List] [Patent Literature] [0006] [Patent Literature 1] JP S60-22591 A [Patent Literature 2] JP 2011-121446 A

[Summary of Invention]

[Technical Problem] [0007] However, JP 60-22591 A and JP 2011-121446 A are completely silent or do not mention any use of the slats 2015 with respect to the positive increase of a drag force of the sail 2010 produced by the slots 2015. To the contrary, the configuration is adopted where the slats 2015 cannot generate a significant drag force due to the formation of the large gap S between the sail body 2011a and each slat 2015.

[0008] In general, a drag force of a sail is expressed by a following formula: FD = 1/2 pV? CD A wherein FD = drag force.

p = density of air (typically at sea level at a temperature of 20°C).

V -velocity of air.

Cu = drag coefficient.

A = area of the object facing the direction of airflow.

[0009] As a result of extensive studies on a drag force of the sail, the inventor of the present invention has found that a drag force can be considerably increased by attaching a sail drag increasing member to a side edge or a surface of a sail body without forming a gap between the side edge or the surface of the sail body and the sail drag increasing member or without forming a significant gap between the side edge or the surface of the sail body and the sail drag increasing member.

[0010] It is an object of the present invention to provide a sail having a sail drag increasing member which can considerably increase a drag force of the sail of a ship or the like. [Solution to Problem] [0011] (1) According to an aspect of the present invention, there is provided a sail having a sail drag increasing member, the sail including: a sail body; and the sail drag increasing member attached to an edge or a surface of the sail body without forming a gap or without forming a significant gap between the edge or the surface of the sail body and the sail drag increasing member. [0012] In the above-mentioned configuration, the technical feature "without forming a significant gap" means that the gap or the space between the edge or the surface of the sail body and the sail drag increasing member does not generate an airflow through the gap to such an extent that the aerodynamic profile or the characteristic of the sail in terms of the coefficients of lift or drag is changed by more than 5%. In other words, the gap formed between the edge or the surface of the sail body and the sail drag increasing member is a gap that is formed only for the purpose of allowing the movement between these parts. or a gap that is necessary and sufficient for mounting the sail drag increasing member on the sail body or for attaching the sail drag increasing member to the sail body (see Fig. 2D, Fig. 18A, Fig. 19A in attached drawings).

[0013] Further, the sail having a sail drag increasing member according to the present invention also has the following technical features.

(2) The sail drag increasing member is attached to a plurality of side edges of the sail body without forming a significant gap between the sail body and each of the sail drag increasing members.

(3) The sail drag increasing member is formed of a raised strip-shaped plate raised at the side edge of the sail body from one surface of the sail body.

(4) The sail drag increasing member is formed of a flat plate where a longitudinal center portion of one surface of the flat plate is attached to the side edge of the sail body, the sail drag increasing member extending in a direction perpendicular to the sail body.

(5) The sail drag increasing member has a straight-line transverse cross section.

(6) The sail drag increasing member has a curved transverse cross section.

(7) The sail drag increasing member is movable relative to the sail body.

(8) One end of the sail drag increasing member is pivotally connected to the sail body so as to allow the sail drag increasing member to pivotally move relative to the sail body.

(9) The sail drag increasing member is configured to change an aerodynamic profile of the sail drag increasing member.

(10) The sail is fixedly mounted on a deck or a superstructure of a ship directly or by way of a mast.

(11) The sail is movably mounted on a deck or a superstructure of a ship directly or by way of a mast. 3 (12) The sail is configured to be stored in a housing by a storing module.

(13) The sail is configured to be movable, rotatable or extendable.

(14) The sail is configured to automatically change a position of the sail by a computer-controlled positioning system.

(15) The sail is configured to automatically change a posture of the sail by a computer-controlled posture changing system.

(16) The sail includes a sail support which supports the sail on a deck.

(17) The sail includes a support means which assists a storage of the sail or fixes the sail in place. [0014] (18) Further, according to another aspect of the present invention, there is provided a ship equipped with the sail having any one of the above-mentioned configurations (1) to (17). [0015] (19) Further, according to another aspect of the present invention, there is provided a sail securing method, wherein the sail according to any one the above-mentioned configurations (1) to (17) is fixed to the ship when the sail is lowered.

[0016] (20) Further, according to another aspect of the present invention, there is provided a sail module including: the sail according to any one of claims (1) to (19); a mast which supports the sail; and an operating device which lifts, lowers or rotates the sail by way of a mast or without by way of the mast.

[0017] (21) Further, according to another aspect of the present invention, there is provided the sail module which further includes a housing which stores at least the sail and the operating device, and the drag increasing member functions as a cover of the housing. [0018] (22) Further, according to another aspect of the present invention, there is provided a drag increasing member being mounted on a structure of a ship as a standalone device without forming a gap or without forming a significant gap between an edge of the structure of the ship and the sail drag increasing member. [0019] Also in the above-mentioned configuration, the technical feature "without forming a significant gap" means that the gap or the space between the edge or the surface of the structure and the sail drag increasing member does not generate an airflow through the gap to such an extent that the aerodynamic profile or the characteristic of the sail in terms of the coefficients of lift or drag is changed by more than 5. In other words, the gap formed between the edge or the surface of structure of the 4 hull and the sail drag increasing member is a gap that is formed only for the purpose of allowing the movement between these parts or a gap that is necessary and sufficient for mounting the sail drag increasing member on the edge of the sail body or for attaching the sail drag increasing member to the surface of the sail body (see Fig. 27 in attached drawings).

[Advantageous effects of Invention] [0020] According to the present invention, it is possible to provide a sail having a drag increasing member which can increase a drag force and can be stored in a housing or the like in several modes.

[Brief Description of Drawings]

[0021] Fig. 1A is a perspective view showing a sail having a sail drag increasing member according to a first embodiment of the present invention.

Fig. 1B is a transverse cross-sectional view taken along a line I-I in Fig. 1A.

Fig. 2A is a plan view showing a sail having a sail drag increasing member according to a second embodiment of the present invention.

Fig. 2B is aperspective view showing apart of the sail having the sail drag increasing member according to the second embodiment of the present invention.

Fig. 2C is a transverse cross-sectional view taken along a line II-II in Fig. 28.

Fig. 2D is a perspective view showing a sail having a sail drag increasing member according to a modification of the second embodiment of the present invention.

Fig. 2E is a transverse cross-sectional view taken along a line in Fig. 21).

Fig. 3A is a plan view showing a sail having a sail drag increasing member according to a third embodiment of the present invention.

Fig. 31) is a plan view showing a sail having a sail drag increasing member according to a modification of the third embodiment of the present invention.

Fig. 4A is an explanatory plan view showing a sail having a sail drag increasing member according to a fourth embodiment of the present invention.

Fig. 4B is an explanatory plan view showing the manner of operation of the sail having a sail drag increasing member according to the fourth embodiment of the present invention.

Fig. 40 is an explanatory plan view showing the manner of operation of the sail having a sail drag increasing member according to the fourth embodiment of the present invention.

Fig. 41) is a partially enlarged explanatory plan view showing the manner of operation of the sail having the sail drag increasing member according to the fourth embodiment of the present invention Fig. 5A to Fig. 5D are side views of sails having a sail drag increasing member according to a fifth embodiment of the present invention Fig. 6A to Fig. 6D are views showing a sail having a sail drag increasing member according to a sixth embodiment of the present invention.

Fig. 7A to Fig. 7G are perspective views showing sails having sail drag increasing members according to a seventh embodiment of the present invention.

Fig. 8A is a front view showing a sail having a grid-like structure and sail drag increasing members according to an eighth embodiment of the present invention.

Fig. 8B is a front view showing a sail having a grid-like structure and sail drag increasing members according to a modification of the eighth embodiment of the present invention.

Fig. 9A is a perspective view showing a sail module according to a ninth embodiment of the present invention which includes a sail having a sail drag increasing member.

Fig. 9B is a perspective view showing the manner of operation of the sail module according to the ninth embodiment of the present invention.

Fig. 10A is a perspective view showing a sail module according to a tenth embodiment of the present invention which includes a sail having sail drag increasing members.

Fig. 10B is a perspective view showing the manner of operation of the sail module according to the tenth embodiment of the present invention.

Fig. 11A is a side view showing a sail module according to an eleventh embodiment of the present invention which includes a sail having sail drag increasing members.

Fig. 11B is a front view of the sail module according to the eleventh embodiment of the present invention.

Fig. 12 is a side view showing a sail module according to a twelfth embodiment of the present invention which includes a sail having a sail drag increasing members.

Fig. 13 is a side view showing a sail module according to a thirteenth embodiment of the present invention which includes a sail having a sail drag increasing members.

Fig. 14 is a side view showing a sail module according to a fourteenth embodiment of the present invention which includes a sail having sail drag increasing members.

Fig. 15 is a perspective view showing a sail module according to a fifteenth embodiment of the -present invention which includes a sail having sail drag increasing members.

Fig. 16 is a side view showing a sail module according to 6 a sixteenth embodiment of the present invention which includes a sail having sail drag increasing members.

Fig. 17 is a perspective view showing a sail module according to a seventeenth embodiment of the present invention which includes a sail having sail drag increasing members.

Fig. 18A is a perspective view showing a sail module according to an eighteenth embodiment of the present invention which includes a sail having sail drag increasing members.

Fig. 18B is a perspective view showing the manner of operation of the sail module according to the eighteenth embodiment of the present invention.

Fig. 19A is a side view showing a sail module according to a nineteenth embodiment of the present invention which includes a sail having sail drag increasing members.

Fig. 19B is a front view showing the manner of operation of the sail module according to the nineteenth embodiment of the present invention.

Fig. 20A to Fig. 201 are plan views showing the various manners of attaching the sail drag increasing members to the sail body in the first embodiment of the present invention.

Fig. 21A is a schematic plan view which outlines basic forces acting upon a sail with sail drag increasing members according to the present invention mounted on a ship.

Fig. 21B is also a schematic plan view which outlines basic forces acting upon a sail with sail drag increasing members according to the present invention mounted on a ship.

Fig. 22A is a schematic top plan view showing an airflow around a sail having sail drag increasing members according to the first embodiment 1 of the present invention.

Fig. 22B is a schematic plan view showing an airflow around a sail having a sail drag increasing member at one side edge of a sail body according to a modification of the first embodiment 1 of the present invention.

Fig. 22C is a schematic plan view showing an airflow around the sail having sail drag increasing members according to the first embodiment of the present invention in a state where the sail is laid down on a deck or a superstructure of a ship.

Fig. 23A is a side view of a ship on which sails having sail drag increasing members and sail modules according to the present invention are mounted.

Fig. 23B is a plan view of the ship shown in Fig. 23A on which sails having sail drag increasing members and sail modules according to the present invention are mounted.

Fig. 24A is a side view of a ship on which sails having sail drag increasing members and sail modules according to the present invention are mounted.

Fig. 24B is a plan view of the ship shown in Fig. 24A. Fig. 25A is a side view of a ship on which sails having sail 7 drag increasing members and sail modules according to the present invention are mounted.

Fig. 253 is a plan view of the ship shown in Fig. 25A.

Fig. 26A is a side view of a ship on which sails having sail drag increasing members and sail modules according to the present invention are mounted.

Fig. 2613 is a plan view of the ship shown in Fig. 26A. Fig. 27 is a rear view of a ship to which sail drag increasing members according to the present invention are attached.

Fig. 28A is a perspective view of a conventional sail. Fig. 28B is a transverse cross-sectional view of the conventional sail taken along a line IV-IV in Fig. 28A.

Fig. 29A is a plan view showing the configuration of a ship according to the embodiment of the present invention.

Fig. 2913 is an explanatory view showing an imaginary projection plane of each sail.

Fig. 30A is an explanatory view showing the configuration of each sail and the flow of an airflow.

Fig. 303 is an explanatory view showing the configuration of each sail and the flow of an airflow.

Fig. 300 is an explanatory view showing the configuration of each sail and the flow of an airflow.

Fig. 31A is a plan view showing the configuration of a ship according the embodiment of the present invention.

Fig. 313 is an explanatory view showing the configuration of each sail and the flow of an airflow.

Fig. 32A is an explanatory view showing the configuration of each sail and the flow of an airflow.

Fig. 323 is an explanatory view showing the configuration of each sail and the flow of an airflow.

[Description of Embodiments]

[0022] A sail having a sail drag increasing member of the present invention is described hereinafter in conjunction with embodiments with reference to attached drawings.

[0023] (First embodiment) Fig. lA and Fig. 13 are views for describing a sail having a sail drag increasing member according to a first embodiment of the present invention, wherein Fig. TA is a perspective view showing the sail having sail drag increasing members, and Fig. 13 is a transverse cross-sectional view taken along a line I-I in Fig. 1A.

[0024] As shown in Fig. 1A and Fig. 13, a sail 10 is a sail having rigidity referred to as a rigid-type sail, and is formed of: a sail body 12 having a quadrangular plate shape extending in a vertical direction in a use state; and a pair of sail drag increasing members 14 fixedly attached to both side edges 16 of the sail body 12.

To be more specific, although a front side of the sail 10 is described as a flat surface, typically, the front of the sail 10 is curved. The sail drag increasing member 14 is formed of a vertically strip-shaped elongated plate having a widthwise center portion of one surface thereof attached to the side edge 16 of the sail body 12. The sail drag increasing members 14 extend in a direction perpendicular to the sail body 12 in transverse cross section as shown in Fig. 1B. However, it is not always necessary that the sail drag increasing members 14 extend in a direction perpendicular to the sail body 12 and may extend other directions. The sail 10 is supported on a top portion of a mast 18. Typically, the mast 18 would be located at or near the center of the sail 10, but other locations would be possible including locating the mast 18 at or near the side edge of the sail 10. [0025] As can be understood from Fig. 1B, no significant gap is formed between the sail body 12 and respective sail drag increasing members 14.

[0026] With such a configuration, the following advantageous effects can be acquired.

[0027] The advantageous effects are described with reference to Fig. 22A. Fig. 22A is a plan view of the erected sail 10 as viewed from above. As shown in Fig. 22A, an airflow F around and over the sail 10 having two sail drag increasing members 14 becomes as follows.

[0028] The sail drag increasing members 14 provide, in addition to the surfaces of the sail body 12, other surfaces or objects around which air moves. This interaction on these surfaces or objects will result in the sail 10 further producing a drag force and also increasing the sail area 10 to some extent. ParBicularly, as shown in Fig. 22A and Fig. 22B, when an airflow F flows leeward, the sail drag increasing members 14 function like baffle plates so as to make the airflow F to take a large roundabout route thus playing a role of peeling off the airflow more away from the sail 10 (sail body 12).

[0029] Fig. 22c is a representation of the sail 10 with the sail drag increasing members 14 when the sail 10 is lowered with a rear surface of the sail 10 disposed parallel to a deck 17 or a surface on which the sail 10 is installed.

[0030] If no such sail drag increasing members 14 were fitted to the sail body 12, the airflow F over and around the sail 10 would create a lift perpendicular to the top or front surface of the sail 10 and this could force the sail 10 upwards especially during strong winds.

[0031] This effect is the same effect as an airflow flowing around a wing of an aircraft. On the other hand, the sail drag increasing members 14 according to this embodiment would disrupt the airflow F to flow along the surface of the sail 10 (sail body 12) and hence, the sail drag increasing members 14 suppress the production of a lift force, cancel any lift force produced and negates or minimizes any lift force produced and thus the sail 13 would remain securely in position.

[0032] In this embodiment, the sail 10 is supported by the mast 18.

However, it is not always necessary to support the sail 10 by the mast 18, and the sail 10 may be directly supported on a deck or a superstructure of a ship or other means.

[0033] (Second embodiment) Fig. 2A to Fig. 20 are views for describing a sail 110 of a movable type according to a second embodiment of the present invention. Fig. 2A is a plan view of the sail 113 having sail drag increasing members 114. Fig. 23 is a perspective view of a portion of the sail 110 having the drag increasing member 114. As illustrated in the drawing, the sail drag increasing member 114 is movably attached to both side edges 116 of a sail body 112 of the sail 110. Fig. 20 is a Hransverse cross-sectional view taken along a line II-II in Fig. 23. In Fig. 2A, numeral 118 indicates a mast.

[0034] As shown in Fig. 2A to Fig. 20, the sail 110 according to the second embodiment is substantially equal to the sail 10 according to the first embodiment with respect to the configuration where two sail drag increasing members 114 are attached to the sail body 112. That is, the sail drag increasing member 114 is formed of a vertically strip-shaped elongated plate where a width-direction center portion of one side surface of the sail drag increasing member 114 is attached to the side edge 116 of the sail body 112. The sail drag increasing members 114 extend in a direction perpendicular to the sail body 112 as shown in Fig. 23. The sail 10 is supported on a top portion of the mast 118. [0035] However, the sail 110 according to the second embodiment differs from the sail 10 according to the first embodiment with respect to a point that both sail drag increasing members 114 are linearly slidably movable in a windward-leeward direction perpendicular to the sail body 112. However, it is sufficient that at least one of the sail drag increasing members 114 is attached to the sail body 112.

[0036] In the sail 110 according to the second embodiment, a rack plate 120 is fixedly mounted on a top surface of the sail drag increasing member 114, and a pinion 122 which engages with the rack plate 120 is fixedly mounted on a rotary shaft 124 of a motor 126 mounted on an upper portion of the sail body 112.

[0037] With such a configuration, along with the rotation of the rotary shaft 124 driven by the motor 126, the pinion 122 simultaneously rotates, and the rotation of the pinion 122 moves the rack plate 114 on which a rack 120 is fixedly mounted in a windward-leeward direction perpendicular to the sail body 112. [0038] With such a configuration, the sail drag increasing member 114 is linearly movable with respect to the sail body 112 without forming a significant gap between the sail body 112 and the sail drag increasing member 114.

[0039] (Modification of second embodiment) Fig. 21) and Fig. 2E show a modification of the second embodiment. As shown in Fig. 2D and Fig. 2E, a sail 210 according to the modification is substantially equal to the sail 110 according to the second embodiment with respect to the configuration where two sail drag increasing members 214 are movably attached to a sail body 212. That is, the sail drag increasing member 214 is formed of a vertically strip-shaped elongated plate where a longitudinal center portion of one side surface of the sail drag increasing member 214 is attached to a side edge 216 of the sail body 212. The sail drag increasing member 214 extends in a direction perpendicular to the sail body 212 as shown in Fig. 21).

[0040] However, the sail 210 according to the modification differs from the sail 110 according to the second embodiment with respect to a point that both sail drag increasing members 214 are rotatably movable about a rotary shaft 224 described hereinafter.

[0041] As shown in the drawings, a motor 226 (or a similar drive means) is mounted on one side edge of the sail body 212 and the rotary shaft 224 of the motor 226 protrudes from a top surface of the sail body 212. One end of an elongated rotary plate 230 is fixedly connected to the rotary shaft 224, and the other end of an elongated rotary plate 230 is fixed to a center portion of a top edge of the sail drag increasing members 214. One side edge of the sail body 212 forms a circular curved surface 232. The circular curved surface 232 is brought into rotatably slide contact with one surface 234 of the sail drag increasing member 214. In other words, one surface 234 of the sail drag increasing member 214 is rotatable about the rotary shaft 224 while being in slide contact with an inner side edge of the sail body 212. With such a configuration, the sail drag increasing member 214 is rotatably movable without forming a gap between the edge of the sail body 212 and the sail drag increasing member 214. Besides such a configuration, the sail drag increasing member 214 is rotatably movable with a slight gap between the edge of the sail body 112 and the sail drag increasing member 214 but without forming a significant gap between the sail body 112 and the sail drag increasing member 214.

[0042] In the above-mentioned configuration, the technical feature "without forming a significant gap" means that the gap or the space between the edge of the sail body 112 and the sail drag increasing member 114 does not generate an airflow through the gap to such an extent that the aerodynamic profile or the characteristic of the sail in terms of the coefficients of lift or drag is changed by more than 5%. In other words, the gap formed between the edge of the sail body 112 and the sail drag increasing member 114 is a gap that is formed only for the purpose of allowing the movement between these parts. That is, a gap that is necessary and sufficient for mounting or attaching the sail drag increasing member 114 to the sail body 112.

[0043] (Third embodiment) Fig. 3A is a plan view showing a sail 310 having sail drag increasing members 314 according to a third embodiment of the present invention.

[0044] The sail 310 shown in Fig. 3A has substantially the same configuration as the sail 10 of the first embodiment shown in Fig. 1. The sail 310 is characterized by having a sail body 312 and curvedsaildragincreasingmembers314which are fixedly attached to both side edges of the sail body 312. Numeral 318 indicates a mast.

[0045] Fig. 3B is a plan view showing a sail 410 having sail drag increasing members 414 according to a modification of the third embodiment of the present invention.

[0046] The sail 410 shown in Fig. 3B has substantially the same configuration as the sail 210 of the modification of the second embodiment shown in Fig. 2D and Fig. 2E. The sail 410 is characterized by having a sail body 412 and curved sail drag increasing members 414 which are slidably or rotatably attached to both side edges of the sail body 412. A linear movement mechanism or a rotary movement mechanism for linearly moving or rotating the curved sail drag increasing member 414 is substantially equal to the mechanisms described in the second embodiment and the modification of the second embodiment and hence, the description of the linear movement mechanism and the rotating movement mechanism is omitted in the third embodiment. Numeral 418 indicates a mast.

[0047] With such a configuration, the sail drag increasing member 414 is linearly or rotatably movable without forming a significant gap between the edge of the sail body 412 and each sail drag increasing member 414.

[0048] (Fourth embodiment) As shown in Fig. 4A to Fig. 45) which are plan views, in a sail 510 according a fourth embodiment includes: a sail body 512; curved sail drag increasing members 514 which are attached to both side edges of the sail body 512; and rotary mechanisms 513 which extend the curved sail drag increasing members 514 in a direction toward or away from the sail body 512. The rotary mechanism 513 is formed of: a rotary shaft 524 which is connected on a proximal end of the curved sail drag increasing member 514; and a motor 546 disposed on a side edge of the sail body 512 and is connected to the rotary shaft 524. Numeral 548 is a mast.

[0049] With such a configuration, the sail drag increasing members 514 could be adjusted to maximize an area facing the direction of an airflow.

[0050] Also with such a configuration, the sail drag increasing member 514 is rotatably movable without forming a significant gap between the side edge of the sail body 512 and the sail drag increasing member 514.

[0051] (Fifth embodiment) Fig. SA to Fig. 5D are side views of sails having a sail drag increasing member used according to a fifth embodiment of the present invention; [0052] Although some examples of the sails 10, 110, 210 and 310 and the sail drag increasing members 14, 114, 214, 314 have been described heretofore, one or more sail drag increasing members could be incorporated into the design of the sails. For example, the following configurations are considered with respect to the sail 10 and the sail drag increasing members 14 according to the first embodiment. The sail drag increasing members 14 could extend for the full length (Fig. SA, Fig. SC) of the sail body 12 or be smaller than the full length of the sail body 12 (Fig. 53, Fig. 53).

That is, various combinations of sail drag increasing members in terms of sizes, shapes, designs, mounting numbers and mounting positions would be possible. This would allow for a wide range of sail modifications to be possible by using a relatively simple device. As shown in Fig. 5C, the sail drag increasing member 14 may be vertically movable by an elevating mechanism 14a. Further, as shown in Fig. 5D, the sail drag increasing member 14 may be rotatably movable by a rotating mechanism 14b. Variations in terms of shapes and mounting numbers of sail drag increasing members 14 without the mast 18 would also be possible.

[0053] (Sixth embodiment) Fig. 6A is a perspective view showing a sail 610 having a sail drag increasing member 614 according to a sixth embodiment of the present invention.

[0054] The sail 610 is characterized in that one elongated strip-shaped sail drag increasing member 614 is attached to a top end of a sail body 612. Numeral 618 indicates a mast. Also with such a configuration, the sail drag increasing member 614 is attached to the sail body 612withoutforminga gap ora significant gap between the sail body 612 and the sail drag increasing member 614.

[0055] Fig. 613 to Fig. 6D are schematic cross-sectional views, as viewed in a direction taken along a line V-V in Fig. 6A, of the sail drag increasing member 614 where the sail drag increasing member 614 is mounted on the sail body 612 having various shapes. Fig. 6B shows the sail body 612 having a wing-type cross section, Fig. 6C shows the sail body 612 having a crescent or flattened U-shaped cross section, and Fig. 6D shows the sail body 612 having a flattened isosceles triangular cross section.

[0056] (Seventh embodiment) Fig. 7A to Fig. 75 are perspective views showing sails 710A to 7105 having sail drag increasing members 714 according to a seventh embodiment of the present invention.

[0057] Fig. 7A to Fig. 75 illustrate how sail drag increasing members 714 could be also attached to side edges or a top edge of a sail body 712 and also on the surface of the sail body 712. For example, Fig. 7B shows a mode where the sail drag increasing member 714 is attached to only one side edge of the sail 710B (Fig. 73). Fig. 7F shows a mode where the sail drag increasing members 714 is attached to all edges the sail body 712.

[0058] Fig. 75 shows the sail 7105 having the sail drag increasing members 714 which are mounted on the sail surface of the sail body 712. Although the sail drag increasing members 714 are mounted on the sail surface of the sail body 712 horizontally in Fig. 7G, the sail drag increasing members 714 may be mounted vertically on the sail surface or may be mounted diagonally or obliquely on the sail surface. Such structure can also increase a drag force and can also protect the sail 710 from damage due to cargo operations and from falling objects. Additionally, the sail drag increasing members 714 would also strengthen the sail structure. Numeral 718 indicates a mast.

[0059] Also with such a configuration, the sail drag increasing member 714 is attached to the sail body 712 without forming a gap or a significant gap between the sail body 712 and each sail drag increasing member 714.

[0060] (Eighth embodiment) Fig. 8A is a front view showing a sail 740a according to an eighth embodiment of the present invention that includes: a grid-like frame structure; and sail drag increasing members 744a. [0061] As shown in Fig. 8A, the sail 740a includes a sail body 742a formed in a frame-like shape, and a plurality of panels 750, 751 and 752. Some of these panels are breakable when the sail 740a receives a strong wind. The sail drag increasing members 744a are attached to both side edges of the sail body 742a, and are expandable like double-hinged doors as shown in Fig. 8B. [0062] Fig. 8B is a front view showing a sail 740b according to a modification of the eighth embodiment of the present invention. The sail 740b of the modification differs from the sail 740a with respect to a point that the sail 740b has the sail drag increasing members 744a not only on both side edges of the sail body 742a but also on a top edge of the sail body 742a.

[0063] In this embodiment, the sail drag increasing members 744a would increase a drag force generated by the sail 740b and also could provide other advantages including providing protection for the sail 740b when raised or lowered.

[0064] This type of sail 740b could also be used for offshore power applications with the sail drag increasing members 744a protecting the sail 740b in the raised or lowered position. [0065] Also with such a configuration, the sail drag increasing member 744a is attached to the sail body 742a without forming a gap or a significant gap between the sail body 742a and the sail drag increasing member 744a.

[0066] (Ninth embodiment) Fig. 9A is a perspective view showing a sail module M1 according to a ninth embodiment of the present invention which includes a sail 810 having a sail drag increasing member 814. Fig. 93 is a perspective view showing the manner of operation of the sail module M1 according to the ninth embodiment of the present invention.

[0067] In this embodiment, the sail 810 which is formed of a sail body 812 and the sail drag increasing member 814 mounted on a top edge of the sail body 812 is formed as a part of the sail module Ml. In other words, the sail module M1 is formed of: the sail 810; a mast 818 which supports the sail 810; an operating device 820 which lifts, lowers, and rotates the sail 810 by way of the mast 818; a base plate 822 or a deck which supports the sail 810, the mast 818 and the operating device 820; and a top open-ended rectangular parallelepiped housing 824 which encases the above-mentioned parts.

[0068] With such a configuration, the sail 810 takes a posture where the sail 810 is stored in the housing 824 when the sail 810 is not used as shown in Fig.9A, and the sail 810 takes a posture where the sail 810 is lifted and is rotatable and inclinable when the sail 810 is in use as shown in Fig.9B. When the sail 810 is not used as shown in Fig.9A, the sail drag increasing member 814 functions as a cover which prevents the intrusion of rains or the like into the housing 824.

[0069] That is, when the sail 810 is lowered and/or stored in the housing 824, the sail drag increasing member 814 could provide a protective cover. The sail drag increasing member 814 could be made from a suitable material for this purpose. On the other hand, a material of the sail drag increasing member 814 is not limited. It is sufficient that the sail drag increasing member 814 simply has a shape which allows the sail drag increasing member 814 to provide the above-mentioned protection cover.

[0070] The sail drag increasing member 814 could also be large enough to form a part of the sail module M1 or to cover the sail body 812 thus reducing the need for a separate module and also allowing the sail 810 to be stored on a ship's deck.

[0071] Since the sail drag increasing member 814 could form a part of the sail module M1 or the housing 824, the sail module M1 can be simplified in construction and in designing.

[0072] Also with such a configuration, the sail drag increasing member 814 is attached to the sail body 812 without forming a gap or a significant gap between the sail body 812 and the sail drag increasing member 814.

[0073] (Tenth embodiment) Fig. 10A is a perspective view showing a sail module M2 according to a tenth embodiment of the present invention which includes a sail 810 having sail drag increasing members 814. Fig. 10B is a perspective view showing the manner of operation of the sail module M2 according to the tenth embodiment of the present invention.

[0074] The tenth embodiment is substantially a modification of the ninth embodiment, and only differs with respect to a point that a sail body 812 has a sail drag increasing member 814 not only on a top edge of the sail body 812 but also on both side edges of the sail body 812. Other configurations are equal to the corresponding other configurations of the ninth embodiment and hence, the description of other configurations is omitted. [0075] Also with such a configuration, the sail drag increasing members 814 are attached to the sail body 812 without forming a gap or a significant gap between the sail body 812 and the sail drag increasing members 814.

[0076] (Eleventh embodiment) Fig. 11A is a side view showing a sail module M3 according to an eleventh embodiment of the present invention which includes a sail 810 having sail drag increasing members 814. Fig. 11D is a front view showing the manner of operation of the sail module M3 according to the eleventh embodiment of the present invention. [0077] The eleventh embodiment is substantially a modification of the ninth embodiment. However, the eleventh embodiment is described in a simplified manner. The eleventh embodiment only differs from the ninth embodiment with respect to points that a mast 818 has a mechanism 818a which allows the mast 818 and the sail 610 to be tiltable, that is, to be raised and lowered between a vertical position and a horizontal position, and the sail module M3 further includes sail supports 826 which support the sail 810 or the sail drag increasing members 814 when the sail 810 is disposed at the horizontal position.

[0078] In the above-mentioned configuration, the sail drag increasing members 814 may be also configured to secure the sail 810 on the sail supports 826 mechanically or electro-mechanically. For example, the sail support 826 could incorporate an electrical magnetic device that could be activated when the sail 810 is lowered and the electrical magnetic device would secure the sail 810 in place by magnetically attracting the metal-made sail drag increasing members 814 or metal plates attached to the sail drag increasing members 814 by a magnetic force.

[0079] Also with such a configuration, the sail drag increasing members 814 are attached to the sail body 812 without forming a gap or a significant gap between the sail body 812 and the sail drag increasing members 814.

[0080] (Twelfth embodiment) Fig. 12 is a side view showing a sail module M4 according to a twelfth embodiment of the present invention which includes a sail 810 having a sail drag increasing member 814.

[0081] The twelfth embodiment is substantially a modification of the eleventh embodiment. The twelfth embodiment only differs from the modification of the eleventh embodiment with respect points that the sail drag increasing member 814 is attached to a top edge of a sail body 812, and the sail drag increasing member 814 is supported by a sail support 828.

[0082] Also with such a configuration, the sail drag increasing members 814 are attached to the sail body 812 without forming a significant gap between the sail body 812 and the sail drag increasing member 814.

[0083] (Thirteenth embodiment) Fig. 13 is a side view showing a sail module M5 according to a thirteenth embodiment of the present invention which includes a sail 810 having a sail drag increasing member 814.

[0084] The thirteenth embodiment is substantially a modification of the twelfth embodiment. The thirteenth embodiment only differs from the twelfth embodiment with respect points that the sail drag increasing member 814 is attached to a side edge of a sail body 812, the sail module M5 further includes an additional mast 818a attached to the sail body 812 on a side opposite to a mast 818, the mast 818a is supported on a sail support 828, and the sail 810 is stored in a state where surfaces of the sail body 812 extend in a vertical direction.

[0085] Also with such a configuration, the sail drag increasing member 814 can be attached to the sail body 812 without forming a gap or a significant gap between the sail body 812 and the sail drag increasing member 814. The sail drag increasing member 814 also protects the sail body 812 from falling objects.

[0086] (Fourteenth embodiment) Fig. 14 is a side view showing a sail module M6 according to a fourteenth embodiment of the present invention which includes a sail 810 having sail drag increasing members 814.

[0087] The fourteen embodiment is a modification of the thirteenth embodiment. The fourteenth embodiment only differs from the modification of the thirteenth embodiment with respect to points that the sail drag increasing member 814 is attached to both side edges of a sail body 812, and the sail module M6 further includes an additional sail support 828a which is disposed below the center of one side edge of the sail body 812 and supports the sail 810 from below.

[0088] Also with such a configuration, the sail drag increasing member 814 is attached to the sail body 812 without forming a gap or a significant gap between the sail body 812 and the sail drag increasing member 814.

[0089] (Fifteenth embodiment) Fig. 15 is a perspective view showing a sail module M7 according to a fifteenth embodiment of the present invention which includes a sail 810 having a sail drag increasing member 814. [0090] The fifteenth embodiment is a modification of the thirteenth embodiment. The fifteenth embodiment only differs from the modification of the thirteenth embodiment with respect to points that the sail module M7 has a rectangular parallelepiped housing 824a in which substantially all parts of the sail module M7 are disposed, and the sail drag increasing member 814 also plays a role of a cover which prevents the intrusion of rain or the like when the sail module M7 is stored in the housing 824a.

[0091] Also with such a configuration, the sail drag increasing member 814 is attached to the sail body 812 without forming a gap or a significant gap between the sail body 812 and the sail drag increasing member 814.

[0092] (Sixteenth embodiment) Fig. 16 is a side view showing a sail module M8 according to a sixteenth embodiment of the present invention which includes a sail 810 having a sail drag increasing member 814.

[0093] The sixteen embodiment is a modification of the thirteenth embodiment. The sixteenth embodiment differs from the thirteenth embodiment with respect to a point that an end portion of the sail drag increasing member 814 is supported by a sail support 828.

[0094] Also with such a configuration, the sail drag increasing member 814 is attached to the sail body 812 without forming a gap or a significant gap between the sail body 812 and the sail drag increasing member 814.

[0095] (Seventeenth embodiment) Fig. 17 is a perspective view showing a sail module M9 according to a seventeenth embodiment of the present invention which includes a sail 810 having a sail drag increasing member 814.

[0096] The seventeen embodiment is a modification of the fifteen embodiment. The seventeenth embodiment differs from the fifteenth embodiment with respect to points that the sail 810 including the sail body 812 and the sail drag increasing member 814 is stored in a housing 824b, and an operating device 820 is not stored in the housing 824b.

[0097] Also with such a configuration, the sail drag increasing member 814 is attached to the sail body 812 without forming a gap or a significant gap between the sail body 812 and the sail drag increasing member 814. The sail drag increasing member 814 also plays a role of a cover when the sail module M9 is stored in the housing 824b.

[0098] (Eighteenth embodiment) Fig. 18A is a perspective view showing a sail module M10 according to an eighteenth embodiment of the present invention which includes a sail 810 having three sail drag increasing members 814.

[0099] As shown in Fig. 18A, the sail drag increasing members 814 are attached to both side edges of the sail body 812 and a top edge of the sail body 812 respectively, and two sail drag increasing members 814 are attached to both side edges of the sail body 812 by hinges 830 in an extendable and shrinkable manner laterally. With such a configuration, the sail drag increasing members 814 could expand for the full length (Fig. 18A) of the sail 810. The sail drag increasing member 814 attached to the top edge of the sail body 812 also plays a role of a cover when the sail module M10 is stored in a housing 824c.

[0100] That is, the laterally extendable and shrinkable sail drag increasing members 814 could also allow for the size of the sail 810 to be adjusted. Accordingly, as shown in Fig. 18B, the sail module M10 would take up less space when the sail 810 is lowered or stored compared to a developed state shown in Fig. 18A. When the sail drag increasing members 814 are fully extended as shown in Fig. 18A, the sail area and chord length of the sail 810 would be at their maximums.

[0101] However the sail drag increasing members 814 could also be partially extended and the extension of the sail drag increasing members 814 could be adjusted to suit the prevailing weather conditions.

[0102] For example when strong wings were present, the sail area of the sail 810 could be reduced thus leading to a reduction of force on the sail and the mast.

[0103] Also with such a configuration, the sail drag increasing members 814 are attached to the sail body 812 without forming a gap or a significant gap between the edge of the sail body 812 and the sail drag increasing member 814.

[0104] (Nineteenth embodiment) Fig. 19A is a side view showing a sail module Mll according to a nineteenth embodiment of the present invention which is a modification of the sail module M10 shown in Fig. 18A. Fig. 193 is a front view showing the sail module M11 according to the nineteenth embodiment of the present invention.

[0105] The sail module Mll differs from the sail module M10 only with respect to a point that the sail drag increasing member 814 attached to the top edge of the sail body is supported by a sail support 832.

[0106] The folded sail drag increasing members 814 could also be used to support and/or protect the sail 810 when lowered to take a horizontal state. In a case where the sail 810 is stored with the top of the sail drag increasing members 814 positioned in a horizontal surface, the sail drag increasing members 814 also protect the sail body 812 from falling objects.

[0107] Also with such a configuration, the sail drag increasing member 814 is attached to the sail body 812 without forming a gap or a significant gap between the sail body 812 and the sail drag increasing member 814.

[0108] (Other technical features of the present invention) Fig. 20A to Fig. 201 are plan views showing sail drag increasing members 14 describing various manners of attaching the sail drag increasing members 14 to the sail body 12 in the first embodiment of the present invention (see Fig. 1A). As shown in Fig. 20A to Fig. 201, the sail drag increasing members 14 are mounted on left and right end edge portions of the sail body 12 that has a sail surface thereof directed in a windward and leeward direction in a state where the sail drag increasing members 14 extend in a vertical direction of the sail body 12.

[0109] The sail drag increasing members 14 shown in Fig. 20A to Fig. 20C are attached to the sail body 12 perpendicular to the sail body 12. The sail drag increasing members 14 shown in Fig. 203 to Fig. 20F are attached to the sail body 12 horizontal or parallel to the sail body 12. The sail drag increasing members 14 In Fig. 20G to Fig. 201 are attached to the sail body 12 in an inclined manner with respect to the sail body 12.

[0110] In all cases described above, the sail drag increasing members 14 could be mounted on the sail body 12 in a fixed manner or in a moveable manner.

[0111] Fig. 21A and Fig. 213 schematically show basic forces acting upon asail 10 having sail drag increasing members. That is, these drawings schematically show basic forces acting upon, for example, the sail 10 shown in Fig. 1A having the sail drag increasing members 14 in a case where the sail 10 is mounted on the ship S that is a powered ship. Fig. 21A shows the forces when an apparent wind is from directly behind the sail 10 and Fig. 213 shows the forces for one crosswind scenario. In these drawings, numeral 50 indicates a bow of the ship S, and numeral 51 indicates a stern of the ship S. [0112] The direction and magnitude of these forces would vary due to a number of factors including the angle of the apparent wind relative to the ship S and the positions and sizes of the sail drag increasing members 14.

[0113] Generally speaking, the aim of the sail drag increasing member 14 in terms of a drag force would be to increase the drag force. Asa result, the sail drag increasing member 14 can enhance a propulsive force generated in the direction of the ship's movement.

[0114] Fig. 22A is a top plan view showing an airflow around the sail 10 having sail drag increasing members 14 according to the first embodiment 1.

[0115] Fig. 22B is a side view showing an airflow around the sail 10 having a sail drag increasing member 14 only at upper side of the sail body 12 according to a modification of the first embodiment 1.

[0116] Fig. 22C is a side view showing an airflow around the sail 10 having sail drag increasing members 14 according to the first embodiment in a state where the sail 10 is laid down on a hatch of a ship.

[0117] In other words, Fig. 22A and Fig. 22B illustrate airflow around and over the sail 10 having side sail drag increasing members 14 (Fig. 22A) and the too sail drag increasing member 14 (Fig. 22B). In these drawings, numeral 12a indicates a front surface of the sail body 12, and numeral 12b indicates a rear surface of the sail body 12.

[0118] In these cases, the sail drag increasing members 14 provide another surface or an object for the air to move around. Thus, this interaction of the airflows on these surfaces or objects will result in the sail 10 producing more drag and also increase to some extent a sail area.

[0119] Fig. 22C is a representation of the sail 10 having the sail drag increasing members 14 when lowered with the rear surface 10b of the sail 10 parallel to a deck 17 or a surface on which the sail 10 is installed.

[0120] If no sail drag increasing members 14 were fitted, then the airflow over and around the sail 10 would create a lift force perpendicular to the top or front surface, and such a phenomenon could force the sail 10 upwards especially during strong winds. [0121] This is the same effect as an airflow flowing around the wing of an aircraft. However, the sail drag increasing members 14 would disrupt this airflow and negate or minimize any lift produced and thus the sail 10 would remain securely in position. When sails having sail drag increasing members are fitted to a ship, they could be installed in a variety of ways with different types of sails also included.

[0122] In installing the sail having the sail drag increasing members on a ship, the sail can be installed in various modes including a mode where the sail is installed together with a sail of a different type.

[0123] Also different arrangemenhs of the sail drag increasing members could be used on the same ship.

[0124] Some possible variations of how the sail 10 having the sail drag increasing members could be used on three common ship types are shown in Fig. 23 to Fig. 27.

[0125] Sails having sail drag increasing members and sails without sail drag increasing members could be used together on a ship and a sail with sail drag increasing members could still be stored in a sail module.

[0126] Fig. 23A and Fig. 233 illustrate how sails having sail drag increasing members might be arranged on a bulk cargo ship 51. As shown in these drawings, sail modules M21 to M26 are mounted on a deck of the ship Si. The modules M21 to M26 may adopt a sail drag increasing member or sail drag increasing members including the sail drag increasing members shown in Fig. 7A to Fig. 7G. In Fig. 23A and Fig. 23B, symbol HC indicates a hatch cover.

[0127] Fig. 24A and Fig. 243 illustrate how sails having sail drag increasing members might be arranged on a tank ship 52. As shown in these drawings, sail modules M31 to M35 are mounted on a deck of the tank ship 52. The sail modules M31 to M35 may adopt a sail drag increasing member or sail drag increasing members including the sail drag increasing members shown in Fig. 7A to Fig. 7G. In Fig. 24A and Fig. 243, symbol P indicates piping, symbol DC indicates a deck crane, symbol DF indicates a device installed on the deck.

[0128] Fig. 25A and Fig. 253 illustrate how sails having sail drag increasing members could be utilized on a ship 53 which adopts other zero emission power technologies such as solar panels. As shown in these drawings, sail modules M41 to M45 are mounted on a deck of the ship 53. The sail modules M41 to M45 may adopt a sail drag increasing member or sail drag increasing members including the sail drag increasing members shown in Fig. 7A to Fig. 7G. In Fig. 25A and Fig. 25B, the symbol SP indicates photovoltaic power generation panels, and symbol DE' indicates a device installed on the deck. The sails having sail drag increasing members could also be fitted with photovoltaic power generation panels as described in Japan Patents 5828409 and US Patent 9,376,167 and as shown on impressions of the Aquarius Eco Ship (Eco Marine Power Co. Ltd., 2018).

[0129] A variety of fixed and moveable sail drag increasing members could be used on a ship and these could be combined with sails with or without sail drag increasing members or other sail-assisted propulsion devices as shown in Fig. 26A and Fig. 26B.

[0130] In Fig. 26A and Fig. 2613, modules M51, and movable or fixed sail drag increasing members DM1 to DM6 are mounted on a deck of 24 a ship 54. The modules M51 and the drag force increasing members DM1 to DM6 may adopt a sail drag increasing member or sail drag increasing members including the sail drag increasing members shown in Fig. 7A to Fig. 7G. In the drawings, symbol LF indicates lifeboats disposed on sides of the ship.

[0131] The drag increasing members can be used also on a ship having neither sails nor masts. An example of such arrangement is shown in Fig. 26A and Fig. 26B. The movable sail drag increasing members or the fixed sail drag increasing members DM1 to DM6 mounted on the hull of the ship 54 can be used to increase a drag force in an advancing direction of the ship when apparent airflows from a region behind the ship as indicated by symbol TW in Fig. 26B. Further, the sail drag increasing members Dl to D6 can be used to decrease a drag force derived from the airflow that acts against a propulsion force in an advancing direction of the ship when apparent airflows from a stern side as indicated by symbol MW in Fig. 26B.

[0132] For example, as in the case of the sail drag increasing member DM5, in the case of the headwind, the sail drag increasing member M5 deflects air around the safe boat and around other parts mounted on the deck for decreasing the air resistance. However, when air blows from behind the ship, a surplus resistance is generated in the advancing direction of an azimuth of the ship.

[0133] To describe further, in a case where there is provided ship fittings such as life boats on side walls of the hull in a protruding manner from the side walls, the sail drag increasing members may be arranged on the side walls of the hull at positions closer to a bow than the ship fitting. With such arrangement, when the ship receives a wind from astern (a headwind), by bringing about a state where the sail drag increasing members are inclined toward a stern side as in the case of the sail drag increasing members DM5, it is possible to prevent the wind from impinging on the ship fittings thus becoming resistances at the time of advancing the ship. On the other hand, when the sail drag increasing members receive a wind from a stern side (tail wind), by bringing about a state where rhe sail drag increasing members are inclined toward the stern side or are expanded to sides of the hull, it is possible to increase a drag force toward an advancing direction of the ship.

[0134] Additionally, sails having sail drag increasing members and simplified storage housings or modules could be integrated more easily with ship designs and/or with ship fittings since these devices could form parts of the superstructure or be integrated with the superstructure.

[0135] Drag increasing members 1014 each of which is movable by a movement mechanism could also be used on a ship 35 without a sail or mast or in combination with sails and masts when necessary. The combination of these parts is shown in Fig. 27.

[0136] The drag increasing members 1014 could be utilized to increase a drag force in the direction of ship's movement when the apparent wind is blowing from regions behind the ship S5. The drag increasing members 1014 could be also utilized to reduce a drag force acting against the propulsive force in the direction of ship's movement when the apparent wind was from over the bow. [0137] For example, the drag increasing members 914 could deflect air around a lifeboat or other deck fixture when headwinds were present in order to reduce aerodynamic drag, but then create extra drag in the direction of movement or ship's heading when winds were coming from behind the ship.

[0138] To describe the drag increasing members 1014 more specifically, the drag increasing members 1014 are attached to a hull 1016 and superstructure 1018 so as to increase the area facing the direction of airflow for winds coming from astern of the ship 35 as shown in Fig. 27. The drag increasing member 1014 is rotatably movable without forming a gap between the drag increasing member 1014 and the hull 1016, a gap between the drag increasing member 1014 and the superstructure 1018 or without forming a gap or a significant gap between the drag increasing member 1014 and the hull 1016 and between the drag increasing members 1014 and the superstructure 1018.

[0139] In such a configuration, the technical feature "without forming a significant gap" means that the gap or the space between the edge of the hull 1016 or the superstructure 1018 and the drag increasing member 1014 does not result in airflow through the gap to such an extent that the aerodynamic profile or characteristics in terms of the coefficients of lift or drag are changed by more than 5=. In other words, the technical feature "without forming a significant gap" means that a gap formed the edge of the hull 1016 or the edge of the superstructure 1018 is a gap sufficient to attach the drag increasing members 1014 to the sail body 1012. [0140] By adding the extra surface area, an extra drag force can be produced in the direction of the movement of the ship. Accordingly, the sail drag increasing member 1014 functions as a supplementary source of a propulsive force.

[0141] Conversely, the drag increasing members 1014 could be extended in an emergency to assist the ship S5 in reducing speed if headwinds were present since the resulting drag force in that situation would act against the forward movement of the ship S5. [0142] When required, the drag increasing members 1014 attached to the hull 1016 and the superstructure 1018 could be retracted or folded, or conversely could be fitted in fixed positions.

[0143] Next, with respect to the sails having the sail drag increasing members, the arrangement structure of the sails on the deck is described. In making use of a drag force acquired by the sails as a propulsive force of the ship, to obtain a larger drag force, a mode is considered where a plurality of sails are installed on the deck.

[0144] For example, to consider a case where some large-sized sails 10 as shown in Fig. 1A are arranged on the deck in an overlapping manner in a bow-stern direction, a larger drag force (propulsive force) can be acquired. However, usually, with respect to the sail on a lee side, the wind toward the sail on a lee side is interrupted by the sail on a wind side and hence, a wind receiving efficiency of a lee side is decreased.

[0145] In this respect, by increasing a distance between the sails which are arranged in an overlapping manner, the influence exerted on the sail on a lee side by the sail on a wind side is decreased and hence, the improvement of the wind receiving efficiency is expected. However, it is considered efficient to arrange the sails as much as possible on the deck for increasing a drag force, and it is necessary to install a large number of ship fittings necessary for navigation on the deck. Accordingly, there may be a case where it is difficult to take a large distance between the sails.

[ 0146] Accordingly, with respect to the arrangement structure of the sails when the sails are arranged upright on the deck of the ship, it is the present circumstance that there is still room for improvement from a viewpoint of the efficient generation of a drag force.

[0147] The inventor of the present invention has made extensive studies on this problem and has made a finding of a novel means that can overcome the above-mentioned problem, and has completed the present invention. Hereinafter, the present technique is described with reference to the drawings. In the description made hereinafter, the description is made using two sails for the sake of convenience of the explanation, it is needless to say that two or more sails can be mounted on the deck upright.

[0148] Fig. 29A is an explanatory view of the configuration on the deck 17 of the ship S6 as viewed in a plan view schematically. On the deck 17 of the ship 36, two sails 910a, 910b are mounted upright with a predetermined distance therebetween in a state where two sails 910a, 910b overlap with each other in a bow-stern direction. Further, Fig. 29A also shows a state where an apparent wind (indicated by a blanked arrow) that forms a tailwind from a stern 902 side to a bow 901 side.

[0149] The sail 910a is a sail that is disposed on a stern side in view of the relative relationship with the sail 910b, and is a sail positioned on a windward side in the present situation. [0150] With respect to the sail 910a, a sail drag increasing member 914a having an elongated rectangular flat plate shape is fixedly arranged on one side edge portion (a left side edge portion 950L) and another side edge portion (a right side edge portion 950R) of the sail body 912 in a state where the sail drag increasing members 914a extend over the entire length in the longitudinal direction(in the depth direction as viewed in a plan view of a sheet surface on which Fig. 29A is drawn) of both left and right side portions 950L, 95OR thus forming a drag increasing structure 91 [0151] The sail drag increasing members 914a that form a drag increasing structure 91 have portions thereof in the vicinity of side portions thereof to left and right portions 950 of the sail body 912 such that a most portion of the sail drag increasing member 914a in the width direction protrudes perpendicularly toward a wind receiving surface 951 side as shown in the drawing. No significant gap is formed between the sail body 912 and the sail drag increasing member 914a. In the drawing, symbol 918 indicates a mast.

[0152] The sail 910b is a sail that is disposed on a bow side in view of the relative relationship with the sail 910a, and is a sail positioned on a leeward side in the present situation. [0153] Further, in the same manner as the sail 910a, the sail drag increasing member 914b having an elongated rectangular flat plate shape is fixedly arranged on the left side edge portion 950L and the right side edge portion 95OR of the sail body 912 in a state where the sail drag increasing members 914b extend over the entire length in the longitudinal direction (in the depth direction as viewed in a plan view of a sheet surface on which Fig. 29A is drawn) of both left and right side portions 950L, 950R) thus forming a drag increasing structure P2.

[0154] However, mounting of the sail drag increasing member 914b that forms the drag increasing structure P2 on the sail body 912 differs from mounting of the sail drag increasing member 914a that forms the drag increasing structure P1 on the sail body 912. That is, the sail drag increasing members 914b that form the drag increasing structure £2 have portions thereof in the vicinity of side edge portions thereof to left and right edge portions 950 of the sail body 912 such that a most portion of a length of the sail drag increasing member 914b in the width direction protrudes sideward approximately horizontally with a wind receiving surface 951 as shown in the drawing.

[0155] That is, with respect to the relationship between the sail 910a and the sail 910b, to particularly focus on the drag increasing structures P1, P2, it must be noted that the drag increasing structures P1 attached to the sail 910a disposed relatively on a windward side (stern side) is constructed by arranging the sail drag increasing member 914a such that a wind receiving area (a projection area) of the sail 910a is smaller than a wind receiving area (a projection area) of the sail 910b relatively on a leeward side (bow side).

[0156] In other words, the drag increasing structures P1 attached to the sail 910a disposed relatively on a windward side (stern side) and the drag increasing structures P2 attached to the sail 910b disposed relatively on a leeward side (bow side), with respect to the wind receiving area (projection area) of each sail 910, respectively adopt the structure where a windward side is relatively narrow and a leeward side is relatively wide, and more preferably, the structure where aprojection shape on the windward side falls within the projection shape of the leeside shape while maintaining the above-mentioned relationship.

[0157] Fig. 29B is an explanatory view schematically showing imaginary projection planes of the sail 910a and the sail 910b. As illustrated on the left view of Fig. 29B, the imaginary projection area R1 of the sail 910a has a total area of an area of an imaginary projection region R1a derived from the sail drag increasing member 914a mounted on a left side edge portion 950L, an area of an imaginary projection region Rib derived from the sail drag increasing member 914a mounted on the right side edge portion 950R, and an area of an imaginary projection region Rlc derived from the sail body 912.

[0158] On the other hand, as illustrated on the right view of Fig. 29B, the imaginary projection area R2 of the sail 910b has a total area of an area of an imaginary projection region R2a derived from 29 the sail drag increasing member 914b mounted on a left side edge portion 950R, an area of an imaginary projection region R2b derived from the sail drag increasing member 914b mounted on a right side edge portion 950R, and an area of an imaginary projection region R2c derived from the sail body 912.

[0159] To compare these sails 910a, 9lOb, in this embodiment, the imaginary projection region R1c on the imaginary projection plane R1 of the sail 910a and the imaginary projection region R2c on the imaginary projection plane R2 of the sail 910b adopt the same sail body 912 and hence, have the same projection area. However, the imaginary projection regions Rla, Rlb of the imaginary projection plane R1 and the imaginary projection regions R2a, R2b of the imaginary projection plane R2 differ from each other in the projection area due to the difference in the drag increasing structure, and the relationship of area of imaginary projection plane R1 < area of imaginary projection plane R2 is established. [0160] That is, the area of the imaginary projection plane of each sail 910 is set such that the area of the imaginary projection plane on the windward side is relatively narrow and the area of the imaginary projection plane on the leeward side is relatively wide derived from at least the drag increasing structure formed on each sail 910. In this embodiment, the sail 910a and the sail 910b adopt the same sail body 912 and hence, the imaginary projection region Ric and the imaginary projection region R2c have the same projection area. However, it is needless to say that the configuration that satisfies the above-mentioned condition is provided by making the sizes of the projection areas of parts other than the drag increasing structure different as in the case of the sail body 912, in addition to the difference in the drag increasing structure.

[0161] Further, as shown in Fig. 29B, with respect to the imaginary projection plane R1 of the sail body 910a and the imaginary projection plane R2 of the sail body 910b, the projection shape on a windward side falls within the projection shape of the leeward side. Such structure is brought due to difference in the drag increasing structures adopted by the respective sails 910.

[0162] The drag force generated by each sail 910 differs also due to the wind direction of an apparent wind. However, even when the wind direction changes, the ship and the sail arrangement structure according to the present invention are the above-mentioned sail arrangement configuration that satisfies the above-mentioned condition.

[0163] By adopting such a configuration, as shown in Fig. 30A, when an apparent wind from a stern side reaches the sail 910a, the apparent wind impinges on the wind receiving surface 951 and is dispersed along the wind receiving surface 951. A dispersed part of the apparent wind moves toward a portion where the drag increasing structure P1 is formed as indicated by an airflow Fal. [0164] The airflow in the vicinity of the drag increasing structure P1 is forced to take a large roundabout route as indicated by an airflow Fa2 by the drag increasing structure Pl. Accordingly, as indicated in a mesh pattern in the drawing, an unstable airflow and a vortex are generated behind the sail 910a on a leeside thus generating a large pressure drag force that leads to the generation of a propulsive force of the ship.

[0165] Here, the area of the imaginary projection plane R2 of the sail 910b is larger than the area of the imaginary projection plane R1 of the sail 910a, and the drag increasing structures P2 are formed on both left and right sides in a protruding manner by a width dl. Accordingly, the sail 910b that is positioned on a relatively leeward side can also realize the effective generation of a drag force by capturing again the airflow that contributes to the generation of the drag force by making the airflow to take a large roundabout route around the drag increasing structure P1 like the airflow Fa2.

[0166] Further, not to mention the airflow Fa3 that has reached the inside compared to the airflow Fa2 (close to the center of the sail 910b), also with respect to a wind (airflow) like an airflow Fa4 that cannot be captured by the sail 910a on a front stage, such an airflow can be captured by the sail 910b on a rear stage. Accordingly, compared to a ship which is not provided with the sail arrangement structure of a ship according to the present invention, it is possible to generate a large drag force.

[0167] Fig. 30B is an explanatory view showing the sail arrangement structure according to another ship 37. As can be understood by viewing Fig. 30A, the flowing manner of the airflow indicated by a lower half portion of the drawing that is the airflow substantially in line symmetry with the flowing manner of the airflow in an upper half portion of the drawing with respect to a boundary indicated by a chained line in the drawing and hence, in Fig. 30B, the lower half portion is omitted. Hereinafter, there may be a case where a part of the configuration may be illustrated in the same manner in the description made hereinafter.

[0168] The sail arrangement structure of the sail of the ship 57 shown in Fig. 30B has substantially the same structure as the sail 31 arrangement structure of the sail of the ship 56 described above. However, the sail arrangement structure of the sail of the ship S7 differs with respect to the drag increasing structure of the sail 910c disposed on a windward side.

[0169] More specifically, most portions of lengths in a width direction of the sail drag increasing members 914c disposed on left and right side edge portions 950 of the sail body 912 are made to project toward a wind receiving surface 951 side. However, unlike the drag increasing structure P1 described previously where the sail drag increasing members project at a right angle toward the wind receiving surface 951 side, the drag increasing member 914 is disposed slightly inwardly so as to make an acute angle between the sail drag increasing member 914c and the wind receiving surface 951. Accordingly, no significant gap is formed between the sail body 912 and the sail drag increasing-member 914c. [0170] According to such arrangement structure of the sail, when an apparent wind from a stern side reaches the sail 910c, the apparent wind impinges on the wind receiving surface 951, and a part of the apparent wind dispersed along the wind receiving surface 951 advances toward a part where the drag increasing structure P3 is installed as indicated by an airflow Fb1. [0171] An airflow in the vicinity of the drag increasing structure P3 is, compared to the airflow Fa2 described above, largely turned back toward the inside of the sail like the airflow Fb2 shown in Fig. 30B. Accordingly, a complicated turbulence of airflow is generated on a wind receiving surface 951 side compared to the sail 910a so that a drag force is increased.

[0172] Further, the airflow Fb3 which is generated as the apparent wind directly impinges on the sail drag increasing members 914c flows in the direction away from the sail 910c by the sail drag increasing members 914c disposed in an inclined manner toward the inside. Accordingly, the enlargement of a pressure drag force region (indicated in a mesh pattern) generated behind the sail 910c on a leeward side is enhanced and hence, a drag force is increased.

[0173] Further, not to mention an airflow Fa4 which reaches the inside (close to the center of the sail 910c) compared to the airflow Fa3, a wind (an airflow) that cannot be captured by the sail 910c on the front stage such as an airflow Fa5 can be also captured by the sail 910c on a rear stage. Accordingly, compared to the case where the ship is not provided with the sail arrangement structure according to this embodiment and the sail arrangement structure of the above-mentioned ship 56, a large crag force can be generated.

[0174] With respect to both sail arrangement structures of the ship 36 and the ship 37 described above, the description has been made by taking the case where each of the respective sails 910a to 910c has the drag increasing structure 914 only on the left and right side edge portions 950 as an example. However, the present invention is not limited to the above-mentioned configuration, and each of the respective sails 910a to 910c may be provided with the drag increasing members 914 in various modes shown in Fig. 5A to Fig. 8B such as an upper side portion, a lower side portion or a surface of the wind receiving surface 951, or a mode where some configurations in some modes among these modes are combined with each other. For example, to the side edge por:,ion on a side where the sail drag increasing member 714 is not disposed on the sail 710B, the sail drag increasing members 714 disposed on the sail 710A on the same side may be disposed. These arrangements are applicable to the sails disposed on the bulk cargo ship 31 and the sails disposed on the tank ships 52, 53 and the ships 54, 35 described above. Also, unless otherwise specified, the above-mentioned arrangements are applicable to sails according to some examples described later.

[0175] Further, with respect to each of the sail arrangement structures of the ships 56 and the ship 57 described above, the description has been made with respect to the case where all of the sails 910a to 910c are installed upright on the deck 17 in a stand-alone manner. However, the sails 910a to 910c may be provided in any mode among the above-mentioned sail modules (sail modules M1 to M11, the sail modules M21 to M26, the sail modules M31 to M35 and the sail modules M41 to M45) or in modes of the sail modules where partial configurations of some modules among these modules are combined with each other. That is, each of the sail bodies 910a to 910c is provided to the ship as the sail module, and hence, each of the sail bodies 910a to 910c may include various mechanisms such as a rotation and tilting mechanism, an extending and retracting mechanism, a storing mechanism, a protective structure and the like. These arrangements are applicable to the sails disposed on the bulk cargo ship 31 and the sails disposed on the tank ships 52, 53 and the ships 54, 55 described above. Also, unless otherwise specified, the above-mentioned arrangements are applicable to sails according to some examples described later.

[0176] Fig. 30C is an explanatory view showing the deck 17 of the ship 38 on which sail modules not illustrated in the drawing are installed as viewed from above. Although an apparent wind that the ship 58 receives is the same tailwind as the ship 57 shown in Fig. 30B receives, the ship S8 shown in Fig. 30C differs from the ship 37 shown in Fig. 30B with respect to a point that the apparent wind is more or less inclined with respect to the stern-bow direction, and the directions of the sails 910c, 910b differ from each other.

[0177] Sails 910c, 910b shown in Fig. 30C are installed upright on the deck when necessary as parts of the configuration of the sail module not shown in the drawing. That is, each sail module includes a mast rotating device which functions as a mast rotating means and a mast extending and retracting device which functions as a mast extending and retracting means.

[0178] In the above-mentioned configuration, the mast rotating means is a means which rotates the mast at the time of displacing a facing azimuth of a wind receiving surface 951 of the sail installed upright on the deck 17 or at the time of rotating the mast about an axis of the must for displacing the sail to a posture for storing in storing the sail. The mast extending and retracting means is a means which displaces the sail between an upright erected posture where the sail is erected upright on the deck in a wind receivable manner and a storing posture that is provided to substantially prevent the sail from receiving a wind. Each sail extending and retracting means includes the means that extends or retracts the sail as shown in Fig. 11A to Fig. 17, Fig. 19A and the like in a raising and lowering manner, not to mention the means that vertically extends or retracts the sail such as the respective sail modules shown in in Fig. 9A to Fig. 10B, Fig. 18A and Fig. 18B. To describe in other words, these mast rotating means and the sail extending and retracting means can be realized as, for example, a mast rotating mechanism, a mast rotating device, a sail extending and retracting mechanism or a sail extending and retracting device. The mast rotating means and the sail extending and retracting means can be attached to the sail modules described in the present specification when necessary. In acquiring the grant of the patent on the present application, the applicant does not exclude the configuration where these means, mechanisms and devices are added to the sail module and the configuration where these means, mechanisms and devices are excluded from the sail module in executing the patent right when the patent is granted. [0179] By rotating the mast 918 about its axis in the direction indicated by an arrow by the mast rotating mechanism of the sail module not shown in the drawing, the sail 910c is rotated in conformity with the wind direction of the apparent wind so that the wind receiving surface 951 faces the windward. Accordingly, even in a case where the wind direction is changed more or less, the sail 910c can efficiently generate a drag force.

[0180] Further, also with respect to the sail 910b, by rotating the mast 918 about its axis, the wind receiving surface 951 is made to face the windward, and an airflow Fcl which cannot be captured by the sail 910c on the front stage can be captured by the sail 910b on the rear stage using the sail drag increasing member 914b. Accordingly, compared with the case where the sail arrangement structure of a ship according to this embodiment is not provided, the sail 910b can generate a large drag force.

[0181] That is, the drag increasing structure P3 is configured by arranging the sail drag increasing member 914a such that the wind receiving area (projection area) of the sail 910c becomes relatively smaller than the wind receiving area (projection area) of the sail 910b disposed on the leeward side (stern side) . Accordingly, in addition to the efficient generation of a drag force derived from the arrangement of the sail drag increasing member 914a, the efficient generation of a drag force can be also realized by rotating the mast.

[0182] Fig.31A is an explanatory view of the configuration on a deck 17 of a ship 59 schematically showing as a plan view. On the deck 17 of the ship S9, two sails 910c, 910b shown in Fig.31B are installed upright in a state where the sails 910c, 910b are spaced apart by a predetermined interval in a stern-bow direction in an overlapping manner with each other. Further, Fig.31A shows a state which becomes an apparent wind (indicated by a white blanked arrow) that forms a tail wind inclined with respect to the stern-bow direction blows from a stern 902 side to a bow 901 side. However, in Fig.31A, for the sake of convenience of the description, the sails 910c, 910b are not shown in the drawing, and the masts 918 of the sails 910c, 910b and the configuration of main parts of the mast position moving means provided to the sail modules and described later are shown. On the other hand, in Fig.31B, the description of the sail module and the mast position moving means described later is omitted and the positional relationship between the sails is mainly shown.

[0183] As described previously, the sail module may include the mast rotating means and the mast extending and retracting means when necessary. However, in this embodiment, the sail module includes a mast position moving mechanism that moves a mast 918 in a chord direction as a mast position moving means.

[0184] Rails 952 shown in Fig. 31A and bases 953 which are configured to be slidable and be fixed on the rails 952 form parts of the mast position moving mechanism of the sail module not shown in the drawing. By moving the masts 918 disposed on the bases 953 together with the bases 953, it is possible to arrange and fix the sails 910c, 910b on the deck 17 at arbitrary positions in the ship direction.

[0185] As shown in Fig.31B, against the apparent wind which is the stern wind that is inclined more or less with respect to the stern-bow direction, the sails 910c, 910b which are arranged at an approximately center portion in the ship direction of the hull indicated by a broken line on the rail 952 are moved toward a left ship side by a length L1 with respect to the sail 910c, and toward a right ship side by a length L2 with respect to the sail 910b so that the sails 910c, 910b are disposed substantially in an overlapping manner in the longitudinal direction with respect to the wind direction. Further, the respective sails 910c, 910b are brought into a state where the wind receiving surface 951 faces in the windward direction by the mast rotating mechanism of the sail module.

[ 0186] With such a configuration, irrespective of the advancing direction of the ship 39, with respect to the relationship between the wind direction and the sails, it is possible to provide the situation substantially equal to the situation shown in Fig. 303 and hence, the efficient generation of a drag force can be realized. In other words, the drag increasing structure 93 is configured by arranging the sail drag increasing member 914a such that the wind receiving area (projection area) of the sail 910c becomes relatively smaller than the wind receiving area (projection area) of the sail 910b disposed on the leeward (stern side) . Accordingly, in addition to the efficient generation of a drag force derived from the arrangement of the sail drag increasing member 914a, the efficient generation of a drag force can be also realized by rotating the mast and moving the mast.

[0187] Fig.32A is an explanatory view showing a sail arrangement structure of another ship S10. Fig. 32A shows substantially the same arrangement structure and substantially the same wind diction situation as Fig. 30A. However, the sail arrangement structure shown in Fig.32A differs from the sail arrangement structure shown in Fig.30A with respect to a point that a shape of a sail drag increasing member 914d that a sail 910d on a relatively windward side has and a shape of a sail drag increasing member 914e that a sail 910c on a relatively leeward side has differ from each other, and a point that the sail arrangement structure of another ship S10 includes a sail drag increasing member posture displacement member that is capable of changing angles of the sail drag increasing members 914d, 914e and support positions of the sail drag increasing members 914d, 914e on the side edge portions of sail body 912.

[0188] In the sail 910d, a drag increasing structure P4 is formed as follows. Sail drag increasing members 914d are arranged on one side edge portion (a left side edge portion 950L) and the other side edge portion (a right side edge portion 950R) of the sail body 912 over an approximately entire length in a longitudinal direction (a direction extending perpendicular to a surface of a sheet on which drawing is depicted) by way of a posture displacement mechanism 954. Although the sail drag increasing member 914d has an elongated rectangular shape, the sail drag increasing member 914 has is not a flat plate and is curved in an arcuate shape in a width direction (lateral direction).

[0189] The sail drag increasing member 914d that forms the drag increasing structure P4 is configured such that a portion of one side edge portion of the drag increasing structure P4 disposed at the position in the vicinity of one side is supported on left and right side edge portions 950 by way of a posture displacement mechanism 954, a portion of the sail drag increasing member 914d which covers a major portion of a length in the lateral direction protrudes toward a wind receiving surface 951 side as shown in the drawing, and an imaginary plane 01 which connects the other side edge portion and the one side edge portion of the sail drag increasing member 914d to each other is arranged in a state where the imaginary plane 01 is approximately orthogonal to the wind receiving surface 951 as viewed in a plan view by the posture displacement mechanism 954. No significant gap is formed between the sail body 912 and the sail drag increasing member 914d.

[0190] On the other hand, the sail 910c is a sail that is disposed on a relatively bow side with respect to the relationship with the sail 910d. In this embodiment, the sail 910c is a sail which is positioned on a leeward side in the situation described above. [0191] Further, in the same manner as the sail 910d, in the sail 910e, a drag increasing structure PS is formed as follows. Sail drag increasing members 914e are arranged on a left side edge portion 950L and a right side edge portion 95OR of the sail body 912 over an approximately entire length in a longitudinal direction (a direction extending perpendicular to a surface of a sheet on which drawing is depicted) by way of a posture displacement mechanism 954. Although the sail drag increasing member 914e has an elongated rectangular shape, the sail drag increasing member 914e is not formed of a flat plate and is curved in an arcuate shape in a width direction (lateral direction). [0192] However, mounting of the sail drag increasing member 914e that forms the drag increasing structure PS on the sail body 912 37 differs from mounting of the sail drag increasing member 914d that forms the drag increasing structure P4 on the sail body 912. That is, the sail drag increasing member 914e is configured such that a portion of one side of the drag increasing structure P5 disposed at the position in the vicinity of one side edge portion is supported on left and right side edge portions 950 by way of a posture displacement mechanism 954, and an imaginary plane G2 which connects the other side edge portion and one side edge portion of the sail drag increasing member 914d to each other is arranged in a state where the imaginary plane G2 protrudes toward the wind receiving surface 951 approximately horizontally as viewed in a plan view by the posture displacement mechanism 954. [0193] That is, with respect to the relationship between the sail 910d and the sail 910e, to particularly focus on the drag increasing structures P4, P5, it must be noted that the drag increasing structures P4 attached to the sail 910d disposed relatively on a windward side (stern side) is constructed by arranging the sail drag increasing member 914d such that a wind receiving area (a projection area) of the sail 910d is smaller than a wind receiving area (a projection area) of the sail 910e relatively on a leeward side (bow side) . [0194] By adopting such a configuration, as shown in Fig. 32A, when an apparent wind from a stern side reaches the sail 910d, the apparent wind impinges on the wind receiving surface 951 and is dispersed along the wind receiving surface 951. A dispersed part of the apparent wind moves toward a portion where the drag increasing structure P4 is formed as indicated by an airflow Fdl. [0195] The airflow in the vicinity of the drag increasing structure P4 is forced to take a large roundabout route as indicated by an airflow Fd2 by the drag increasing structure P4. Accordingly, as indicated in a mesh pattern in the drawing, an unstable airflow and a vortex are generated behind the sail 910d on a leeside thus generating a large pressure drag force that leads to the generation of a propulsive force of the ship.

[0196] Here, the area of the imaginary projection plane of the sail 910e is larger than the area of the imaginary projection plane of the sail 910d, and the drag increasing structures P5 are formed on both left and right sides in a protruding manner. Accordingly, the sail 910e that is positioned on a relatively leeward side can also realize the efficient generation of a drag force by capturing again the airflow that contributes to the generation of the drag force by making the airflow to take a large roundabout route around the drag increasing structure P4 like the airflow Fd2.

[0197] Particularly, the sail drag increasing member 914d has the curved structure. Accordingly, the airflow Fd2 which is forced to take a roundabout route flows along an outer side surface of the sail drag increasing member 914a and is straightened so as to be directed toward the inside and hence, it is possible to allow a rear flow to effectively impinge on the sail on a leeward side. [0198] Further, a wind (an airflow) such as an airflow Fd3 that cannot be captured by the sail 910d on a front stage can be captured by the sail 910e on a rear stage. Further, the airflow such as the airflow Fd3 is directed toward the inside of the sail 910e by being guided by the airflow Fd2. Accordingly, compared to a ship which is not provided with the sail arrangement structure of a ship according to the present invention, it is possible to generate a large drag force.

[0199] Particularly, in a case where the sail drag increasing member 914 is attached by way of the posture displacement mechanism 954, a gap may be necessary more or less between the sail body 912 and the sail drag increasing member 914 for moving the sail drag increasing member 914. However, to prevent leakage of an airflow from a wind receiving surface 951 side to a back surface side through the gap, particularly, to prevent the generation of a drag force by such a leakage, a gap closing member which closes the gap while allowing the movement of the sail drag increasing member 914 may be provided. Although such a gap closing member may not be particularly limited, the gap closing member may be realized by extending an elastic membrane or a flexible membrane between the sail body 912 and the sail drag increasing member 914 along the gap in a hermetic manner. With such a configuration, it is possible to interrupt the flow of air through the gap. Even in a case where the flow of air through the gap cannot be completely interrupted, the generation of a drag force can be sufficiently prevented and hence, an efficient generation of a drag can be enhanced. Further, in this case, to prevent a movable range of the sail drag increasing member 914 from being limited as much as possible, both side edge portions of the membrane-like gap closing member that is extended between the sail body 912 and the sail drag increasing member 914 may be intentionally not closed and be held in an open state.

[0200] Fig. 323 is an explanatory view showing a sail arrangement structure of still another ship 511. The sail arrangement structure differs from the sail arrangement structure shown in Fig. 32A with respect to points such as a sail drag increasing member 914d of a sail 910d disposed on a relatively windward side and a posture of a sail drag increasing member 914e of a sail 910e disposed on a relatively windward side. That is, Fig. 32B shows a mode where postures of the sail drag increasing members 914d, 914e are changed by the posture displacement mechanism 954. [0201] To be more specific, in the sail drag increasing member 914d, a drag increasing structure P6 is formed as follows. A portion of the sail drag increasing member 914d which is disposed at an approximately center position in the width direction is supported on left and right side edge portions 950 of the sail body 912 respectively by way of the posture displacement mechanism 954. Further, an approximately half portion of one side edge of the sail drag increasing member 914d in a width direction is arranged so as to protrude toward a wind receiving surface 951 side and an approximately half portion of the other side edge of the sail drag increasing member 914d in the width direction is arranged so as to protrude toward a back surface side. Further, an imaginary plane G3a which connects the other side edge portion and one side edge portion of the sail drag increasing member 914d and an imaginary plane G3b which connect the other side edge portion and one side edge portion of the sail drag increasing member 914d are arranged by the posture displacement mechanism 954 in a state where the imaginary planes G3a, G3b are expanded from the wind receiving surface 951 side to the windward side (stern direction) as viewed in a plan view. No significant gap is formed between the sail body 912 and the sail drag increasing member 914d.

[0202] On the other hand, the sail 910e is configured as follows.

Aportion of the sail drag increasing member 914d which is disposed at a position in the vicinity of one side edge portion is supported on the left or right side edge portion 950 of the sail body 912 by way of a posture displacement mechanism 954. Further, an imaginary plane G4a which connect the other side edge portion and one side edge portion of the sail drag increasing member 914e and an imaginary plane G4b which connect the other side edge portion and one side edge portion of the sail drag increasing member 914e are arranged by the posture displacement mechanism 954 in a state where the imaginary planes 4A, 4b are expanded in a windward direction (stern direction) from a wind receiving surface 951 side at an obtuse angle which is slightly narrower compared to a corresponding angle of the imaginary planes G3a, G3b of the drag increasing structure PS (however, an angle which the imaginary plane G4a and the imaginary plane G4b make with he wind receiving surface 951 being a wide angle compared to the drag increasing structure P6).

[0203] With such a configuration, when an apparent wind from astern side reaches the sail 910d, the apparent wind impinges on the wind receiving surface 951, and a portion of the wind dispersed along 40 the wind receiving surface 951 advances toward a part where the drag increasing structure P6 is constructed as indicated by an airflow Eel.

[0204] Airflows in the vicinity of the drag increasing structure P6 are forced to take a large roundabout route like an airflow Fd2 by the drag increasing structure £6.

[0205] In the above-mentioned configuration, the sail drag increasing members 914d are supported on the left and right side edge portions 950 of the sail body 912 at an approximately center portion in a width direction. Accordingly, as described above, an approximately half portion of the other side edge of the sail drag increasing member 914d is disposed so as to protrude toward a back surface side of the sail body 912, and the sail drag increasing member 914d in the width direction is disposed such that the imaginary planes G3a, G3b are expanded toward a windward side.

[0206] Such arrangement of the sail drag increasing member 914d brings about a situation where the wind that take a roundabout route flows along an arcuate protruding side surface of the sail drag increasing member 914d without being peeled off. Accordingly, as indicated in a mesh pattern, a pressure drag generation region generated by vortices and an unstable airflow becomes slightly narrow compared to a case shown in Fig. 32A and hence, it seems disadvantageous from a viewpoint of the generation of a drag force.

[0207] However, to take into account the presence of the sail 910e on a leeward side together with such a phenomenon, soon, the airflow Fe2 which is separated from the circular protruding side surface of the sail drag increasing member 914d can be largely guided to a position closer to the center of the sail 901e on a rear stage compared to the drag increasing structure P4 shown in Fig. 32A and hence, wind receiving efficiency on a leeward side can be further enhanced.

[0208] That is, while peeling off the airflow by an approximately half portion of one side edge of the sail drag increasing member 914d that protrudes toward a wind receiving surface 951 side, it is possible to straighten the airflow such that the airflow efficiently impinges on the sail on a leeward side by the other-side approximately half portion that protrudes toward a back surface side.

[0209] Further, with respect to such airflow Fe2, the wind (airflow) that cannot be captured by the sail 910d on the front stage such 41 as an airflow Fe3 and an airflow Fe4 which takes a large roundabout route around the sail drag increasing member 914d can be captured by the sail 910e on the rear stage. Accordingly, it is possible to generate a large drag force.

[0210] Further, the drag increasing structure P6 can increase an upper limit of a wind force that can be structurally used to a higher value compared to an upper limit of a wind force generated by the drag increasing structure P4. Accordingly, even in a case where a relatively strong wind blows, it is possible to expect the generation of an efficient drag force.

[0211] Further, also with respect to the drag increasing structure P7, the sail drag increasing member 914e having an expanded shape of a narrow angle compared to the drag increasing structure P5 is disposed. Accordingly, the airflow can be peeled off by forcing the airflow to take a large roundabout route around the sail drag increasing member 914e and hence, a drag force generated by the sail 910e can be further enhanced.

[0212] In Fig. 32A and Fig. 32B, the sail drag increasing member 914d and the sail drag increasing member 914e are configured to be capable of changing their postures by way of the posture displacement mechanism 954. However, the present invention is not limited to such a mode. That is, the sail drag increasing member 914d and the sail drag increasing member 914e maybe fixedly disposed on left and right side edge portions 950 without using the posture displacement mechanism 954 in a mode where the sail drag increasing member 914d and the sail drag increasing member 914e cannot be displaced to other postures.

[0213] Further, the posture displacement mechanism 954 may be configured to manually change the posture of the sail drag increasing member 914. However, the posture displacement mechanism 954 may include a controller for posture displacement and may electrically change the posture of the sail drag increasing member 914d by a control performed by the controller. [0214] To recapitulate the above-mentioned configuration and to add some additional technical features, a sail drag increasing member or a drag increasing member would typically be located on the edge or edges ofa sail, the sail surface or surfaces, or fitted directly to a ship or vessel.

[0215] Sail drag increasing members could be fixed in position or moved either manually or automatically via a movement mechanism or control system.

[0216] The sail drag increasing members could be an intrinsic part of the sail structure and design itself and/or integrated into the structure of the ship.

[0217] The sail drag increasing members could also be manufactured separately and added as sail and/or ship modifications.

[0218] According to the present invention, it is possible to acquire the following advantageous effects.

(1) A drag force produced by the sail canbe increased when airflow is generated onto and around the sail.

(2) The sail drag increasing member can protect the sail and/or sail side edges when the sail is raised or lowered.

(3) The sail drag increasing member forms a part of a storage housing or a module thus simplifying the design of the module or housing.

(4) The sail drag increasing member acts as a hatch or a cover for a sail storage housing or a module.

(5) The sail drag increasing member increases the overall area of the sail.

(6) The sail drag increasing member provides an extra strength and/or support for the sail especially if flexible materials are used for forming the sail.

(7) A surface or surfaces of the sail drag increasing member can be used to support the sail when the sail is stored or lowered.

(8) The sail drag increasing member protects the sail from damage during cargo operations when the sail is raised or lowered.

(9) The sail drag increasing member allows the sail to be integrated more easily into the overall design of the ship by utilizing existing ship designs, structures and/or fitting on ships.

(10) The sail drag increasing member provides removable and replaceable protective devices for sails, sail side edges and other parts of a sail-assisted propulsion device.

(11) The sail drag increasing member reduces or eliminates a lift force when the sail is stored on the deck or other surface of a ship.

(12) A method of controlling the forces exerted on the sail and the mast is provided where a drag profile and a surface area of the sail can be altered when the sail drag increasing member positions is adjusted manually or automatically via a computer control system.

(13) The sail drag increasing member acts as a means to slow down the ship if headwinds are present by being deployed in such a way to increase the aerodynamic drag working against the forward motion of the ship.

(14) The sail drag increasing member provides a simple means to upgrade or modify existing sails on ships. 43 (15) The sail drag increasing member acts as a device that enables the sail to be physically or mechanically restrained either via a mechanical means or electro-magnetically.

(16) The sail drag increasing member acts as a surface or structure to mount other equipment or devices on a sail especially in cases where the sail was made from or partially made from lightweight or flexible materials.

(17) The sail drag increasing member can be affixed directly to the structure of a ship including the hull with or without a mast.

(18) The sail drag increasing member acts as a source of propulsive force when an apparent wind was moving on or around the rear surface of the sail drag increasing member.

(19) The sail drag increasing member acts as a wind shield to deflect airflow around the ship or parts of the ship when an apparent wind was moving across and around the front surfaces of the sail drag increasing member (that is, when the apparent wind direction was from or around the bow of the ship) so as to reduce the drag force acting against the hull and superstructure thus improve fuel efficiency.

(20) The sail drag increasing members act as moveable barriers to block access to some parts of the ship. For example, they could be used to prevent certain areas of the ship whilst the vessel was underway or as an anti-piracy device that would prevent intruders accessing certain areas.

(21) The sail drag increasing members act as air brakes to help slow or stop a vessel by creating additional aerodynamic drag when headwinds are present.

(22) The sail drag increasing members provide a simple means to upgrade or modify existing ships so that they can utilize the power of the wind.

(23) The sail drag increasing member acts as a relatively low cost and simple wind-assisted or sail-assisted propulsion device for new or existing ships and vessels.

(24) The sail drag increasing member Enables ships to alter their aerodynamic profile based on the prevailing wind conditions at a point of time.

(25) The number, sizes and types of sail drag increasing members can be adjusted so that the sail drag increasing members are suitable for all types of sails.

[0219] [Reference Signs List] 1 0: sail 12: sail body 14: sail drag increasing member 16: side edge 1 8: mast

Claims

[Document Name] Claims [Claim]] A sail comprising: a sail body; and a sail drag increasing member attached to an edge or a surface of the sail body without forming a gap or without forming a gap or a significant gap between the edge or the surface of the sail body and the sail drag increasing member.
[Claim 2] The sail having a sail drag increasing member according to claim 1, wherein the sail drag increasing member is attached to a plurality of side edges of the sail body without forming a gap or a significant gap between the sail body and each of the sail drag increasing members.
[Claim 3] The sail having a sail drag increasing member according to claim 1 or 2, wherein the sail drag increasing member is formed of a raised strip-shaped plate raised at a side edge of the sail body from one surface of the sail body.
[Claim 4] The sail having a sail drag increasing member according to claim 1 or 2, wherein the sail drag increasing member is formed of a flat plate having a longitudinal center portion of one surface of the flat plate is attached to the side edge of the sail body, the sail drag increasing member extending in a direction perpendicular to the sail body.[Claim.5] The sail having a sail drag increasing member according any one of claims 1 to 4, wherein the sail drag increasing member has a straight-line transverse cross section.[Claim 6] The sail having a sail drag increasing member according any one of claims 1 to 4, wherein the sail drag increasing member has a curved transverse cross section.[Claim 7] The sail having a sail drag increasing member according to any one of claims 1 to 4, wherein the sail drag increasing member is movable relative to the sail body.[Claim 8] The sail having a sail drag increasing member according to any one of claim 1 or 2, wherein one end of the sail drag increasing member is pivotally connected to the sail body so as to allow the sail drag increasing member to pivotally move relative to the sail body.[Claim 9] The sail having a sail drag increasing member according to 45 any one of claims 1 to 8, wherein the sail drag increasing member is configured to change an aerodynamic profile of the sail drag increasing member.[Claim 10] The sail having a sail drag increasing member according to any one of claims 1 to 9, wherein the sail is fixedly mounted on a deck or a superstructure of a ship directly or by way of a mast.[Claim 11] The sail having a sail drag increasing member according to any one of claims 1 to 9, wherein the sail is movably mounted on a deck or a superstructure of a ship directly or by way of a mast.[Claim 12] The sail having a sail drag increasing member according to any one of claims 1 to 10, wherein, the sail is configured to be stored in a housing by a storing module.[Claim 13] The sail having a sail drag increasing member according to any one of claims 1 to 12, wherein the sail is configured to be movable, rotatable or extendable.[Claim 14] The sail having a sail drag increasing member according to any one of claims 1 to 13, wherein the sail is configured to automatically change a position of the sail by a computer-controlled positioning system.[Claim 15] The sail having a sail drag increasing member according to any one of claims 1 to 14, wherein the sail is configured to automatically change a posture of the sail by a computer-controlled posture changing system.[Claim 16] The sail having a sail drag increasing member according to any one of claims 1 to 15, wherein the sail includes a sail support which supports the sail on a deck.[Claim 17] The sail having a sail drag increasing member according to any one of claims 1 to 13, wherein the sail includes a support means which assists a storage of the sail or fixes the sail in place.[Claim 18] A ship equipped with the sail according to any one of claims 1 to 17.[Claim 19] A sail securing method, wherein the sail according to any one claims 1 to 17 is fixed to the ship when the sail is lowered. [Claim 20] A sail module comprising; the sail according to any one of claims 1 to 17; a mast which supports the sail; and an operating device which lifts, lowers or rotates the sail. [Claim 21] The sail module according to claim 20, further comprising a housing which stores the sail, the mast and the operating device, and the sail drag increasing member functions as a cover of the housing.[Claim 22] A drag increasing member being mounted on a structure of a ship as a standalone device without forming a gap or without forming a gap or a significant gap between an edge of the structure of the ship and the sail drag increasing member.