JP6418451B2 - Ship - Google Patents

Description

  The present invention relates to a ship provided with a duct at the stern.

  In the case of a propeller that rotates clockwise as viewed from the stern due to the bilge vortex generated by the hull on the stern side above the height of the propeller shaft in a displacement type ship such as a general commercial ship, the bilge vortex appears on the port side. A flow in the same direction as the propeller rotation is induced on the outside, a flow in the same direction as the propeller rotation is induced on the starboard side inside the bilge vortex, and the reverse is the case in the case of the left rotation propeller. There is a problem that the relative flow velocity of the motor becomes slower and the propeller efficiency becomes worse.

  As one countermeasure against this, as a ship duct device having a high energy-saving effect and easy to manufacture, a substantially frustoconical outer shell obtained by cutting a substantially frustoconical cylinder into a half in a plane including the central axis; The outer shell is arranged so that the outer shell is directed to the propeller side and the outer shell faces the upper half of the propeller. A ship duct device has been proposed (see, for example, Patent Document 1).

  In this ship duct device, resistance occurs in a portion below the propeller rotation shaft in a normal circular duct, and the resistance increases compared to the thrust by the duct and the energy saving effect is reduced. A semicircular arc duct that leaves only the upper part (outer shell) of the duct that generates thrust, eliminating the lower part of the circular duct so that the duct effectively generates thrust and enhances the rectification effect. Adopt and set the dimensions and height position of this outer shell.

  However, in this ship duct device, it is preferable that the two connecting plates connected to both ends of the outer shell that fixes the outer shell to the stern portion have a shape that hardly resists the water flow through the duct device. However, it is used only as a support structure for the outer shell.

  Furthermore, in this connection, in order to improve the small amount of thrust generated in the side part of the semicircular duct, the propeller provided at the stern and the center of the stern vertical vortex generated at the front of the propeller and at the stern An arc-shaped duct that is arranged above the position and has an enlarged diameter from the rear to the front of the ship, and extends between the lower ends of the duct and the sides of the stern in the radial direction of the propeller. A ship including a main fin that is inclined forward and forward from the front is proposed (see, for example, Patent Document 2).

  In this ship, the main fin is formed in a downwardly projecting wing cross-sectional shape, and tilts forward from the rear of the ship toward the front, and assists from the downward flow flowing from the upper side to the lower side of the duct. It is said that by obtaining thrust, thrust can be generated efficiently and resistance does not increase.

  In addition, the auxiliary fin extended outwardly is formed in an upwardly convex wing cross-sectional shape, and is inclined forward and downward from the rear of the ship toward the front, so that the outer side of the duct is directed upward from below. It is said that by obtaining auxiliary thrust from the flowing upward flow, thrust can be generated efficiently and resistance does not increase.

JP 2008-137462 A JP 2011-178222 A

  As a result of considering the fluid effect of the duct (outer shell) and the strut (connecting plate, main fin) that supports the duct, the present inventors need the duct support function of the strut. The shape of the duct and strut is determined for the purpose of obtaining thrust. However, in addition to thrust generation, the flow direction that rectifies the bilge vortex to weaken the flow in the same direction as the propeller rotation direction and the direction of the water flow flowing into the propeller surface is opposite to the propeller rotation direction. The present invention has been conceived by thinking that it can have a conversion function and not only obtain thrust but also play a major role in improving propeller efficiency.

  The present invention has been made in view of the above situation, and an object of the present invention is to provide a duct having a duct member and a strut supporting the duct member at the stern, and a propeller rotation axis just before the propeller. In a ship arranged above the duct member, the duct member and the strut that supports the duct member can obtain a thrust by the duct member, and the bilge vortex is rectified by the connecting portion between the duct member and the strut to determine the propeller rotation direction. An object of the present invention is to provide a ship capable of improving the propeller efficiency by weakening the flow in the same direction and changing the direction of the water flow flowing into the propeller surface in the direction opposite to the rotation direction of the propeller by the strut.

A ship for achieving the above object is a ship in which a duct having a duct member and a strut that supports the duct member on the hull is disposed immediately above the propeller and above the propeller rotation axis. The struts are connected to both ends of the duct member, and the connecting portion of the duct member and the strut is disposed near the center of the bilge vortex generated at the stern when the duct is not provided, and the duct member is disposed at the front end. The side is formed parallel to the propeller rotation axis than the rear end side , or is formed to be outward with an opening angle of greater than 0 ° and 40 ° or less , and the strut is rotated with respect to the hull longitudinal direction. An angle for guiding the flow component in the direction opposite to the direction to increase is provided, and the height of the propeller rotation axis is set immediately before the propeller. When the direction of the rotator is clockwise when viewed from the stern, it extends to the port side, or when the direction of the propeller is rotated to the left when viewed from the stern, it extends to the starboard side. A first horizontal fin is provided in the vicinity of the propeller rotation circle, and is configured to suppress a flow in the same direction as the propeller rotation direction outside the bilge vortex, and the propeller is set at the height of the propeller rotation axis immediately before the propeller. When the direction of rotation is clockwise when viewed from the stern, it is extended to the starboard side.When the direction of rotation of the propeller is rotated to the left when viewed from the stern, it is extended to the port side. A second horizontal fin is provided in the vicinity of the position in the ship width direction at the center of the bilge vortex so as to suppress the flow in the same direction as the propeller rotation direction inside the bilge vortex .

  According to this configuration, in the duct member, lift is generated by the wing effect caused by the downward water flow flowing along the hull flowing into the upper portion of the propeller surface, and the hull longitudinal component of this lift is used as the thrust. On the other hand, in the strut that supports the duct member on the hull, it is arranged at an angle with respect to the direction of the incoming water flow, and by changing the direction of the water flow, that is, the water flow flowing into the propeller surface is changed in the propeller rotation direction. By changing the flow component in the opposite direction, the propeller propulsion efficiency is increased.

Furthermore, the bilge vortex that develops at the stern, when viewed from the stern, flows in the same direction as the propeller rotation direction on the port side, outside the bilge vortex on the port side, and inside the bilge vortex on the starboard side. In the case of a propeller that rotates counterclockwise, a flow in the same direction as the propeller rotation direction is induced on the starboard side inside the bilge vortex and on the starboard side outside the bilge vortex. By arranging the connecting portion of the bilge vortex near the center of the bilge vortex, the bilge vortex can be rectified by the duct member and the strut, and the flow in the same direction as the propeller rotation direction of the bilge vortex can be weakened.
In addition, the first horizontal fin is configured to suppress the upward flow outside the bilge vortex in front of the propeller, that is, on the port side of the right-handed propeller as viewed from the stern, to the left as viewed from the stern. In the propeller of this type, on the starboard side, the tip side of the first horizontal fin is arranged in a region having a flow in the same direction as the propeller rotation direction, and the water flow is induced so as to have a flow opposite to the propeller rotation direction. Can be raised.
In addition, when the second horizontal fin is configured to suppress the downward flow generated inward from the center of the bilge vortex, it is on the starboard side when viewed from the stern on the starboard side, and on the left side when viewed from the stern. Therefore, since the horizontal fin can be arranged only in the range up to the vicinity of the ship width direction position of the center of the bilge vortex, which has the same flow direction as the propeller rotation direction, this horizontal fin allows the flow in the direction opposite to the propeller rotation direction. The propeller efficiency can be increased by guiding the water flow so that

  In the above-described ship, when the cross-sectional shape of the strut is formed in a shape having a convex camber on the direction in which the propeller rotates, the propeller rotation direction in the water flow flowing into the propeller surface by the strut Since the flow component can be increased in the opposite direction, the propeller efficiency can be improved.

  In the above-mentioned ship, when the cross-sectional shape of the duct member is formed into a wing shape having a convex camber on the inside, the lift generated by the duct member can be increased, and the thrust obtained from the duct can be increased. it can.

  In the above ship, when the cross-sectional shape of the strut is formed in a wing shape, the resistance component acting on the strut can be weakened while maintaining the function of changing the direction of water flow, and the resistance of the strut can be reduced.

  In the above-described ship, when the duct member is configured in a polygonal shape, the duct member can be disposed in a portion more suitable for generating lift than when the duct is formed in an arc shape, and the duct member The angle of attack can be set to an optimum angle with respect to the position of the duct member on each polygon side, and the thrust generated in the duct member can be increased. Note that the polygonal shape increases connection work such as welding of the duct member as compared with the arc shape, but the workability is not deteriorated because it is not necessary to bend the duct member.

  The “horizontal fin” in the “first horizontal fin” and the “second horizontal fin” is substantially horizontal when the ship is viewed from directly behind, for example, at an angle within 10 ° of horizontal plus / minus. , Refers to the fin to be attached. The cross-sectional shape of the first horizontal fin and the second horizontal fin is preferably an airfoil having a leading edge on the bow side and a trailing edge on the stern side.

  ADVANTAGE OF THE INVENTION According to this invention, while generating a thrust with the wing | blade effect of a duct member, the propulsion efficiency of a propeller can be improved by the effect of the direction change of the water flow which flows into the propeller surface in the strut which supports a duct member. Furthermore, by arranging the connection part of the duct member and the strut near the center of the bilge vortex, the bilge vortex generated at the stern can be rectified, and the flow in the same direction as the propeller rotation direction of the bilge vortex can be weakened. Efficiency can be improved.

It is a side view which shows typically arrangement | positioning of the duct in the ship of embodiment of this invention. It is a rear view which shows typically arrangement | positioning of the duct seen from the back of the ship of FIG. It is a side view for demonstrating the opening angle of a duct member. It is a rear view for showing the cross-sectional position of a duct member and a strut. It is Y1-Y1 sectional drawing of FIG. 4 which shows the cross section of a duct member. FIG. 6 is a cross-sectional view taken along the line Y2-Y2 of FIG. 4 showing a cross-section of the starboard side strut (in the case of a right-rotating propeller as viewed from the stern). FIG. 6 is a cross-sectional view taken along the line Y3-Y3 of FIG. 4 showing a cross-section of the port-side strut (in the case of a right-rotating propeller as viewed from the stern). It is a rear view which shows a square-shaped duct typically. It is a rear view which shows typically a pentagonal duct. It is a rear view which shows typically a hexagonal-shaped duct. It is a rear view which shows typically a 1st horizontal fin and a 2nd horizontal fin.

  Hereinafter, a ship according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the ship 1 has a propeller 3 and a rudder 4 at the rear of the hull 2, and at the stern just before the propeller 3 and above the propeller rotation axis Lp, the duct 10. Arranged.

  As shown in FIGS. 1 and 2, the duct 10 includes a duct member 11 and struts 12 a and 12 b that support the duct member 11 on the hull 2. The struts 12 a and 12 b are provided between the end of the duct member 11 and the hull 2. The starboard-side strut 12 a is connected to the starboard side end of the duct member 11, and the port side end of the duct member 11 is connected. A port side strut 12b is connected to the section. That is, the struts 12 a and 12 b are connected to both ends of the duct member 11. 2 indicates a circle drawn by the tip of the propeller 3 (propeller rotation circle), and the diameter of the circle 20 is the propeller diameter Dp.

  And in this invention, as shown in FIG. 2, this connection part 13 of the duct member 11 and struts 12a and 12b is arrange | positioned in the vicinity of the center Pw of the bilge vortex produced in the stern in the case where the duct 10 is not provided. In other words, the front end of the connecting portion 13 is centered on the center Pw of the bilge vortex generated at the stern when the duct 10 is not provided in the plane perpendicular to the propeller rotation axis Lp including the front end, and the radius ra is the propeller diameter. Arranged inside the circle C1 0.15 times Dp. In addition, the position of the center Pw of the bilge vortex when the duct 10 is not provided can be easily specified by calculation using a water tank test or a fluid analysis program.

  As a result, in the duct 10, by bringing the duct member 11 to the center Pw of the bilge vortex, water can flow into the duct member 11 at an appropriate angle of attack to obtain thrust, and the bilge vortex can be obtained by the struts 12a and 12b. As a result, the flow in the same direction as the propeller rotation direction can be converted in the reverse direction, so that the propulsion performance and the propeller efficiency can be improved.

Furthermore, as shown in FIG. 3, the duct member 11 is formed with an opening angle α of 0 ° or more and 40 ° or less where the front end side is more outward than the rear end side with respect to the propeller rotation axis Lp. In other words, the duct member 11 is formed so that the front end side is more parallel to the propeller rotation axis Lp than the rear end side, or is formed outward with an opening angle greater than 0 ° and 40 ° or less. As a result, the duct member 11 generates lift L due to the wing effect caused by the downward water flow W flowing along the hull 2 flowing into the upper portion of the propeller surface Sp, and uses the hull longitudinal component Lf of this lift L as thrust. To do.

  Furthermore, as shown in FIG. 5, it is preferable to form the cross-sectional shape of the duct member 11 into a wing shape having a convex camber on the inside. Thereby, the lift L generated in the duct member 11 can be further increased, and the thrust Lf obtained from the duct 10 can be increased.

  As shown in FIGS. 6 and 7, for the struts 12a and 12b, the angles γa and γb of the lines connecting the front and rear edges of the struts 12a and 12b with respect to the longitudinal direction of the hull are set to 0 ° to 20 °. It is preferable to make it into °.

  With this configuration, the struts 12a and 12b that support the duct member 11 on the hull 2 are arranged at angles βa and βb with respect to the direction of the inflowing water flow W, and change the direction of the water flow W. Since the direction of the water flow W flowing into the propeller surface Sp can be increased by increasing the component of the flow in the direction opposite to the propeller rotation direction R, the effect of increasing the propulsion efficiency of the propeller 3 can be obtained.

  As shown in FIGS. 6 and 7, when the cross-sectional shape of the struts 12a and 12b is formed to have a shape having a convex camber on the direction side R in which the propeller 3 rotates, the struts 12a and 12b are formed. Thus, since the component in the direction opposite to the propeller rotation direction R can be increased in the water flow W flowing into the propeller surface Sp, the propeller efficiency can be improved.

  Moreover, if the cross-sectional shape of the struts 12a and 12b is formed into a wing shape, the resistance component acting on the struts 12a and 12b can be weakened while maintaining the function of changing the direction of the water flow W, and the resistance of the struts 12a and 12b can be reduced. Can be reduced.

  Further, as shown in the ducts 10A, 10B, and 10C as shown in FIGS. 8 to 10, when a polygonal shape such as a quadrangular shape, a pentagonal shape, or a hexagonal shape is used, the duct 10 is formed in an arc shape. In addition, the duct member 11 can be arranged in a portion more suitable for generating the lift L, and the opening angle (attack angle) α of the duct member 11 is set with respect to the position of the duct member 11 on each polygonal side. An optimum angle can be obtained, and the thrust Lf generated in the duct member 11 can be increased. Note that the polygonal shape increases connection work such as welding of the duct member 11 as compared to the arc shape, but the workability is not deteriorated because the duct member 11 need not be bent.

  Further, as shown in FIG. 11, the propeller rotation axis Lp is set to the height immediately before the propeller 3, and when the propeller rotation direction R is a right rotation when viewed from the stern, the propeller rotation direction is not shown. Is provided with first horizontal fins 14 extending in the width direction of the ship from the hull outer plate and having a tip position in the vicinity of the propeller rotation circle 20 on the starboard side when rotating counterclockwise when viewed from the stern. The flow is configured to suppress the flow in the same direction as the rotation direction R. That is, the first horizontal fin 14 whose tip position is in the vicinity R1 of the propeller rotation circle 20 is provided. When the first horizontal fin 14 is viewed from the lateral direction, when the angle at which the front edge is above the rear edge is defined as plus, within ± 30 °, preferably within ± 20 °, more preferably It arrange | positions with an angle of -10 degrees or more and 20 degrees or less. The first horizontal fin 14 guides the water flow so as to suppress the flow in the same direction as the propeller rotation direction R. That is, the first horizontal fin 14 suppresses the upward flow in front of the propeller on the tip side of the first horizontal fin 14, in other words, the upward flow outside the bilge vortex. In FIG. 11, only the starboard side of the bilge vortex is shown for easy viewing.

  As a result, the first horizontal fin 14 is placed in a region having a flow in the same direction as the propeller rotation direction R on the port side of a propeller that rotates clockwise as viewed from the stern or on the starboard side of a propeller that rotates left as viewed from the stern. Since the front end side is arranged and the water flow is induced so as to suppress the flow in the same direction as the propeller rotation direction R, the propeller efficiency can be increased.

  Further, as shown in FIG. 11, the propeller rotation axis Lp is positioned immediately before the propeller 3, and on the starboard side when the propeller rotation direction R is a right rotation when viewed from the stern, or although not illustrated, the propeller rotation direction Is provided with a second horizontal fin 15 extending from the hull skin plate in the ship width direction and having a tip position near the position in the ship width direction of the center Pw of the bilge vortex. It is configured to suppress the flow in the same direction as the propeller rotation direction R inside the bilge vortex. In other words, the second horizontal fin 15 whose tip position is the vicinity R2 of the position in the ship width direction of the center Pw of the bilge vortex is provided. The second horizontal fin 15 is within ± 30 °, preferably within ± 20 °, more preferably −20 ° when the angle at which the leading edge is upward with respect to the trailing edge when viewed from the lateral direction is positive. It arrange | positions with an angle of 10 degrees or more and 20 degrees or less. The second horizontal fin 15 guides the water flow so as to suppress the flow in the same direction as the propeller rotation direction R. In other words, the second horizontal fin 15 suppresses the downward flow generated inside the center Pw of the bilge vortex.

  As a result, the ship at the center Pw of the bilge vortex center Pw has the same flow direction as the propeller rotation direction R on the starboard side in the right-hand propeller 3 as viewed from the stern and on the starboard side in the left-hand propeller 3 as viewed from the stern. Since the second horizontal fin 15 can be disposed only in the range up to the vicinity R2 of the width direction position, the second horizontal fin 15 induces a water flow so as to suppress the flow in the same direction as the propeller rotation direction R, Propeller efficiency can be increased.

  The first horizontal fins 14 and the second horizontal fins 15 are attached substantially horizontally when the ship is viewed from directly behind, for example, at an angle within a horizontal plus / minus 10 °. The cross-sectional shapes of the first horizontal fin 14 and the second horizontal fin 15 are preferably airfoils with a leading edge on the bow side and a trailing edge on the stern side.

  The range R1 in the vicinity of the propeller rotation circle 20 indicating the tip position of the first horizontal fin 14 is a circle of Dp × 0.5 times and a circle of Dp × 1.15 times the propeller diameter Dp. And a range R2 in the vicinity of the position in the ship width direction of the center Pw of the bilge vortex Pw indicating the tip position of the second horizontal fin 15 is the horizontal distance from the center line of the hull is the center of the bilge vortex from the center line of the hull The inside R2 in a range in which the distance to Pw is plus or minus by a distance of 0.15 times the propeller diameter Dp.

  According to the ship 1 having the above-described configuration, the propeller is caused by the thrust Lf generated by the wing effect of the duct member 11 and the direction change effect of the water flow W flowing into the propeller surface Sp in the struts 12a and 12b supporting the duct member 11. 3 propulsion efficiency can be increased. Further, by arranging the connection part 13 between the duct member 11 and the struts 12a and 12b in the vicinity of the center Pw of the bilge vortex, the bilge vortex is rectified and the flow of the bilge vortex in the same direction as the propeller rotation direction R is weakened. Can improve the propeller efficiency.

  According to the ship of the present invention, the propulsion efficiency of the propeller can be increased by the thrust generated by the wing effect of the duct member and the effect of changing the direction of the water flow flowing into the propeller surface of the strut that supports the duct member. Furthermore, by arranging the connection part between the duct member and the strut in the vicinity of the center of the bilge vortex, the bilge vortex can be rectified to weaken the flow of the bilge vortex in the same direction as the propeller rotation direction, and the propeller efficiency can be improved. So it can be used for many ships.

DESCRIPTION OF SYMBOLS 1 Ship 2 Hull 3 Propeller 4 Rudder 10, 10A, 10B, 10C Duct 11 Duct member 12a, 12b Strut 13 Connection site | part 14 1st horizontal fin 15 2nd horizontal fin 20 The circle | round | yen of the tip locus of a propeller (propeller rotation circle)
C1 circle (near the bilge vortex)
Dp Propeller diameter L Lift Lf Thrust Lp Propeller rotation axis Ls Vertical component Pc of lift L Pc Propeller rotation center Pw Bilge vortex center R Propeller rotation direction ra Circle radius Sp Propeller surface W Water flow α Duct member opening angle βa, βb Strut Angle γa, γb Strut angle with respect to hull longitudinal direction δ Angle of water flow with respect to hull longitudinal direction

Claims (1)

In a ship in which a duct having a duct member and a strut that supports the duct member on the hull is disposed above the propeller rotation axis immediately before the propeller,
The struts are connected to both ends of the duct member, and the connection site between the duct member and the strut is disposed in the vicinity of the center of the bilge vortex generated at the stern when the duct is not provided.
The duct member is formed so that the front end side is parallel to the propeller rotation axis than the rear end side , or is formed outward at an opening angle of greater than 0 ° and not more than 40 ° , and
The strut is provided with an angle for inducing the flow component in the direction opposite to the propeller rotation direction to increase with respect to the hull longitudinal direction,
Furthermore, it is set to the height of the propeller rotation axis immediately before the propeller, on the port side when the propeller rotation direction is right rotation when viewed from the stern, or on the starboard side when the propeller rotation direction is left rotation when viewed from the stern. A first horizontal fin extending from the hull outer plate in the ship width direction and having a tip position near the propeller rotation circle is configured to suppress the flow in the same direction as the propeller rotation direction outside the bilge vortex. ,
The hull at the height of the propeller rotation axis immediately before the propeller, on the starboard side when the propeller rotation direction is clockwise when viewed from the stern, or on the port side when the propeller rotation direction is counterclockwise when viewed from the stern. A second horizontal fin that extends from the outer plate in the ship width direction and whose tip position is in the vicinity of the ship width direction position at the center of the bilge vortex suppresses the flow in the same direction as the propeller rotation direction inside the bilge vortex. A ship characterized by being configured to do so .

Images