KR20100097571A - Device for reducing the power demand for the propulsion of a ship - Google Patents

Abstract

PURPOSE: A device for reducing a power demand required for propelling a ship is provided to form a hydrofoil or a hydroplane and to improve efficiency of a propeller. CONSTITUTION: A device for reducing a power demand required for propelling a ship comprises a front nozzle(20). The front nozzle has a cylindrical cross section and is located in the upper side of a propeller of a ship(100). A hydrofoil(30) or a hydroplane is arranged in the inner space(20a) of the front nozzle. The front nozzle is arranged in the ship to be symmetrical with an axis line(21).

Description

DEVICE FOR REDUCING THE POWER DEMAND FOR THE PROPULSION OF A SHIP}

The present invention relates to a device for reducing the power requirements required to propel a single propeller or multiple floppler ship, in particular a broad-built or non-broad-built ship.

DE 42 23 570 C1 discloses a flow guide surface for a pitch controllable propeller. This flow guide surface provides a ring nozzle disposed upstream to affect the flow in a diffuser manner. To this end, flow acceleration in the outer region and flow deceleration in the near region are performed. The diffuser diameter is 65% smaller than the propeller diameter. Such a nozzle is designed as a deceleration nozzle or diffuser with an outwardly curved ring nozzle. The diffuser may slow down the flow in that area and, if a very thick hub is used, such as a pitch controllable propeller, may drive improvement in propulsion efficiency. Therefore, the nozzle is not designed as an acceleration nozzle having a ring nozzle bent inwardly. Thus, the nozzles disclosed in the literature as described above do not accelerate the flow in that area and therefore are not suitable for all propeller shapes, and in particular for fixed propellers. DE 42 23 570 C1 does not describe the effective principle of the front nozzle, which consists of increasing the propeller flow rate in the region where the main stream is very fast.

JP 07 267189A discloses another propeller device comprising a ring nozzle and a fin arranged in a star form. The propeller diameter corresponds almost to the ring diameter of the nozzle.

JP 58 00492A discloses another propeller device which results in a reduction in power requirements for propulsion and an improvement in efficiency. Such a device includes not only a structure comprising six elements arranged in a honeycomb manner, but also a leveler.

It is an object of the present invention to provide an apparatus for reducing the power requirements required for ship propulsion. It is also aimed at improving efficiency and achieving harmonization of horizontal or hydrofoils against the flow. It is also aimed at improving the flow to the propeller.

These objects are achieved by an apparatus having the features of claim 1.

According to the above, the device according to the invention, which is attached to the hull at a short distance from the propeller, is designed in such a way that it includes a front nozzle with a horizontal rudder or hydrofoil disposed therein, wherein the front nozzle at the top passes through the center of the front nozzle. It preferably inclines to 8 ° forward in the horizontal transverse axis that extends.

By means of a device designed in this way, it is possible to reduce the power requirements required for ship propulsion. As the degree of trust load on the propeller increases, the gains that can be obtained also increase. The device is particularly suitable for low speed wide area vessels such as tankers, bulk carriers, tugboats and the like and not very fast vessels. Since the device itself is fixed to the hull, it is arranged upstream of the ship's propeller, and the device comprises two functional elements: a front nozzle and a horizontal rudder or hydrofoil.

In this arrangement, the effective principle of the front nozzle consists of an increase in the flow rate for the propeller in the region where the main stream is very fast, and a decrease in the flow for the propeller in the region where the main stream is slow; The nozzle itself generates a trust, and the effective principle of the horizontal rudder or hydrofoil arranged inside the front nozzle consists of the generation of electric current; The two functional elements aim at different sources of loss, ie the front nozzle aims at effective reduction of thrust loads, and the rudder or hydrofoil aims at reducing vortex losses in the propeller stream. These two effects result in increased efficiency of the propulsion system.

Due to the device attached as close as possible upstream of the propeller, the best effect can be obtained even with different loads.

In addition to the above, the device according to the invention is not only suitable for wide area ships, but also can be used for the same effect even for all ships which are not very fast, for example V ≦ 25 kn and the like. The device can also be used for very large container ships.

Another preferred embodiment forms part of the dependent claims.

In order to achieve the best effect, the trailing edge of the device or front nozzle is not fixed more than 0.3 times the propeller diameter upstream of the propeller plane.

According to another embodiment of the present invention, the front nozzle rotates laterally on a vertical axis extending through the center of the front nozzle, so that the front nozzle is inclined forward on the ups-beating side of the propeller. .

The present invention additionally provides a front nozzle that rotates laterally to 3 ° (preferably 1 °), so that the front nozzle can rotate forward on the upstroke side of the propeller, and the rotation may be 0 °. But not in the other direction.

The present invention also provides a profile form of the front nozzle that is 12% or less in length. The thickness of the profile shape of the front nozzle may be 7.5% or 9% of its length.

Yet another embodiment provides a horizontal rudder or hydrofoil in a radial direction that includes a variable angle of incidence, the horizontal rudder or hydrofoil being twisted so that the horizontal rudder or hydrofoil is directed upward from the inside of the ship, with the angle of incidence outward toward the front nozzle. Is reduced.

Thus, the front nozzle is arranged rotationally symmetrically with respect to the upwardly moved axis disposed above the propeller axis, and the inner diameter of the front nozzle is about 90% of the propeller diameter to the maximum.

Four horizontal rudders or hydrofoils are arranged asymmetrically in the front nozzle radially with respect to the propeller axis; The horizontal rudder or hydrofoil connects the hull to the front nozzle and is disposed at the rear end of the front nozzle; The bent side of the hydrofoil form or profile of the lenticular section of the horizontal rudder or hydrofoil is directed upward on the upward strike side of the propeller and downward on the downward strike side of the propeller. However, the arrangement of four horizontal rudders or hydrofoils in the interior space of the front nozzle is not to be interpreted limitedly, and more or fewer horizontal rudders or hydrofoils may be provided.

The figure shows an embodiment of a ship with a propeller of the device according to the invention, with the propeller at the top rotating towards the starboard.

In FIG. 1 showing the apparatus 1 according to the invention, the front nozzle 20 (front nozzle 20 when attached to the hull) having a cylindrical or other shape or cross section is a propeller of the hull 100. Provided immediately upstream (not shown). A horizontal rudder or hydrofoil 30 is disposed in the interior space 20a of the front nozzle 20. The front nozzle 20 is disposed on the hull so as to be rotationally symmetric with respect to the axis 21 moved upward.

In the exemplary embodiment shown in Fig. 2, four horizontal rudders or hydrofoils 30a, 30b, 30c, and 30d having different lengths of horizontal rudders or hydrofoils are arranged in the inner space 20a of the front nozzle 20. These four horizontal rudders or hydrofoils are arranged asymmetrically in the interior of the front nozzle and radially with respect to the propeller axis PA. In this arrangement, the horizontal rudder or hydrofoil 30a, 30b, 30c, 30d connects the front nozzle 20 to the hull 100, which is disposed at the rear end of the front nozzle 20 The rear end faces the propeller; The hydrofoil shape of the horizontal rudder or hydrofoils 30, 30a, 30b, 30c, 30d or the curved side of the lenticular cross-sectional profile 31 is directed upward at the port side of the ship or the upward striking side of the propeller, and the starboard of the ship It is directed downward on the side or on the down strike side of the propeller. In addition, the horizontal rudder or hydrofoil 30a, 30b, 30c, 30d is directed upward from the front side of the port side, and downwards from the front side of the starboard side (FIGS. 2 and 3). The direction of rotation of the propeller is indicated in the direction of arrow X (Fig. 1). The angular position of the horizontal rudder or hydrofoil 30, 30a, 30b, 30c, 30d disposed in the interior space 20a of the front nozzle 20 is adjustable, and the set angular position can be fixed.

According to an exemplary embodiment with a propeller rotating upward with respect to the starboard, the horizontal rudder or hydrofoil 30a, 30b, 30c, 30d assumes a good radial and initial angular position as follows.

Leveling angle

Port (BB) floor leveler (30a) 247.5 ° 14 °

Port (BB) Medium horizontal rudder (30b) 292.5 ° 12 °

Top port (BB) flat rudder (30a) 337.5 ° 8 ° Starboard (SB) flat rudder (30d) 90.0 ° 10 °

That is, in the horizontal rudder angle (12 o'clock = 0 °, clockwise increase) observed from the rear, the rudder angle and the incident angle may deviate from the values described.

1 and 3 and 6, the horizontal or hydrofoil comprises a lenticular cross-sectional profile 31 having curved sidewalls 32 and a straight bottom region 33. As shown in FIG. In this setting, for example, the arrangement and position of the two horizontal rudders 30 with respect to the propeller axis PA must be such that the base region 33 of the upper horizontal rudder extends almost parallel to the propeller axis PA, The horizontal rudder must extend its base region 33 at an angle α of at least 5 °, preferably 10 °, with respect to the propeller axis PA. Other positions of the horizontal rudder are also possible. Overall, the horizontal hits 30a, 30b, 30c, 30d are in the position shown in FIG.

The front nozzle 20 according to FIGS. 1 and 6 comprises a main body 25 shaped like a cross section profile 26; The cross-sectional profile is a wall portion 26a disposed on the outside and inclined at an angle with respect to the propeller axis PA, and a wall portion 26b disposed on the inside and extending in a straight line parallel to the propeller axis PA. ); In the region facing away from the propeller, the wall portion 26b comprises a curved wall portion 26c which forms a transition to the outer wall portion 26a. The wall portion 26a disposed on the outside may be curved. The propeller side is shown as PS in FIG.

As shown in FIG. 7, the device 10 is attached to the hull 100 at some distance upstream of the propeller 101. In this arrangement, the device 10 is arranged as close as possible upstream of the propeller 101. In this arrangement, the front nozzle 20 is disposed on a horizontal transverse axis extending through the center of the front nozzle, so that it rotates forward by 8 ° at the top. In Fig. 7, the upper part of the front nozzle 20 is inclined forward by 4 degrees. In this arrangement, the trailing edge of the front nozzle 20 is not fixed more than 0.3 times the propeller diameter upstream of the propeller plane.

Further, since the front nozzle 20 is rotatable laterally on a vertical axis extending through the center of the front nozzle, for example, up to 3 °, the front nozzle can rotate forward on the upward striking side of the propeller 101. . Rotation up to 1 ° is considered appropriate in this arrangement. A rotation of 0 ° can also be applied, but not in the other direction.

The thickness of the profile of the front nozzle 20 is 12% or less of its length. The thickness of the profile of the front nozzle 20 is preferably 7.5% or 9% of its length.

The horizontal or hydrofoils 30, 30a, 30b, 30c, 30d in the radial direction may include a variable angle of incidence, which may be twisted such that the horizontal or hydrofoil inside the ship is directed upwards. The angle of incidence is reduced from the outside towards the front nozzle 20 (Figure 8).

The thickness design of the profile of the front nozzle 20 and the design as the horizontal rudder or hydrofoils 30, 30a, 30b, 30c, 30d in the radial direction include a variable angle of incidence are essential for a wide area vessel; This design can also be used on fast ships.

The design of the device 10 according to the present invention results in significant power savings, as is evident in the diagram of FIG. 9, which shows three vessels (two of which have different drafts (X = design speed)). The power savings in the case of using the device 10 for the above are illustrated.

The diagram according to FIG. 10 illustrates the power requirement of a bulk transporter with a deadweight capacity of 118,000 DWT, with or without device 10.

For a ship of 12,000 DWT, for example, the high gain contributes to the thick hub, especially in the case of pitch controllable propellers, the loss of which is reduced by the apparatus 10.

The degree of trust load is especially significant for very large low speed vessels. The diagram of FIG. 11 shows the possible power savings when using the device 10 depending on the C _Th − value. The lower part of Figure 11 provides an assignment for the vessel type.

The device according to the invention is characterized by the embodiments shown in Figs. 1 to 11 and the details set forth in the description and claims.

As devices 10 save fuel or make ships faster, new devices have been developed that improve propulsion of wide-area low speed vessels. The device comprises two elements that are fixedly mounted to the vessel, namely a nozzle disposed just in front of the propeller, and a horizontal rudder system integrally formed therewith. The nozzle improves propeller inflow in the region of adverse wakes and creates its own trust; The leveler system reduces losses in propeller jets and propeller bosses due to current generation, so that propeller trust can be increased for the same drive power.

The power savings that can be achieved by the device depend on the propeller load, which is 3% for small multipurpose ships and 9% for large tankers and cargo ships. Power savings are almost independent of the ship's draught and speed. The device is also suitable for use with new ships and series of installations.

1 is a side view of the apparatus according to the present invention, viewed from the starboard, comprising a front nozzle with a horizontal rudder or hydrofoil disposed in the interior space of the apparatus;

Figure 2 is a perspective view of the apparatus from behind, with the horizontal rudder or hydrofoil shown without an angle of incidence.

3 is an enlarged cross-sectional view of a profile of a horizontal rudder or hydrofoil;

4 is a side view of the stern shape.

5 is a front view of the rear hull.

Figure 6 shows the positional arrangement of the horizontal rudder and shows a front nozzle in which the horizontal rudder or hydrofoil according to the invention is arranged in an interior space.

Figure 7 is a side view of the device, with the front nozzle tilted 4 ° at the top;

Fig. 8 shows a front nozzle in which the horizontal stroke inside the ship is oriented upward and twisted.

9 is a diagram illustrating power savings in the use of the device according to the invention.

Fig. 10 is a diagram showing power requirements with or without the device according to the invention.

11 is a diagram illustrating power savings in the use of the device according to the invention in various types of ships.

[Explanation of symbols on the main parts of the drawings]

10: apparatus 10: front nozzle

20a: internal space 21: axis of front nozzle

25: shaped body 26: cross-sectional profile

26a-26c: wall section 30: horizontal rudder / hydrofoil

30a-30d: Horizontal rudder / hydrofoil 31: Sectional profile

32: curved sidewall 33: base region

100: hull 101: propeller

BB: Porthole SB: Starboard

PA: Propeller Axis PS: Propeller Side

X: direction of propeller rotation α: angle

Claims (13)

Apparatus for reducing the power demands required for propulsion of single propeller or plural floppler vessels, in particular not very fast wide area or non wide area vessels, The device 10 attached to the hull 100 at a short distance from the propeller 101 includes a front nozzle 20 in which horizontal rudder or hydrofoils 30; 30a, 30b, 30c, 30d are disposed therein, And the front nozzle at the top is inclined forward by 8 ° in a horizontal transverse axis extending through the center of the front nozzle. 2. The device of claim 1, wherein the trailing edge of the device or the front nozzle (20) is not fixed more than 0.3 times the propeller diameter upstream of the propeller plane. The apparatus of claim 1 or 2, wherein the front nozzle at the top is inclined about 4 degrees forward. The front nozzle is rotated laterally on a vertical axis extending through the center of the front nozzle so that the front nozzle is moved forward on the upward striking side of the propeller 101. Power demand reduction device. 5. The lateral direction of claim 4, wherein the front nozzle 20 extends up to 3 ° (preferably 1 °) on a vertical axis extending through the center of the front nozzle, such that the front nozzle 20 rotates forward on the upward striking side of the propeller 101. Power demand reduction device, characterized in that for rotating. Device according to any one of the preceding claims, characterized in that the thickness of the profile of the front nozzle (20) is not more than 12% of its length. 7. The apparatus of claim 6 wherein the thickness of the profile of the front nozzle is 7.5% or 9% of its length. 8. The horizontal rudder or hydrofoil 30, 30a, 30b, 30c, 30d in the radial direction comprises a variable angle of incidence, wherein the horizontal rudder or hydrofoil is horizontal inside the ship. The power demand reducing device, characterized in that the rudder or hydrofoil may be twisted upwardly, the angle of incidence being reduced outwardly towards the front nozzle (20). The front nozzle (20) according to any one of the preceding claims, wherein the front nozzle (20) is disposed rotationally symmetrically with respect to the upwardly moved axis (21) disposed above the propeller axis (PA), the inner diameter of the front nozzle being the propeller diameter. Power reduction device, characterized in that less than 90% of. 10. The inner space 20a of the front nozzle 20 according to claim 1, wherein the four horizontal or hydrofoils 30: 30a, 30b, 30c, 30d radially in the propeller axis PA. Is arranged asymmetrically, and the horizontal rudder or hydrofoil connects the hull to the front nozzle (20) and is disposed at the rear end of the front nozzle (20); The curved side 32 of the lenticular cross-sectional profile 31 of the hydrofoil 30: 30a, 30b, 30c, 30d of the horizontal strike or hydrofoil is directed upward on the upward strike side of the propeller and on the downward strike side of the propeller. Power demand reduction device, characterized in that directed downward. The power demand according to any of the preceding claims, wherein the horizontal rudder or hydrofoil 30 (30a, 30b, 30c, 30d) assumes good radial angular and initial angular positions as follows. Reduction device. Leveling angle Port (BB) floor leveler (30a) 247.5 ° 14 ° Port (BB) Medium horizontal rudder (30b) 292.5 ° 12 ° Top port (BB) flat rudder (30a) 337.5 ° 8 ° Starboard (SB) flat rudder (30d) 90.0 ° 10 ° 12. Power demand according to any one of the preceding claims, characterized in that the angular position of the horizontal rudder or hydrofoil 30 disposed in the interior space 20a of the front nozzle 20 can be changed or adjustable. Reduction device. To reduce the power requirement for propulsion of low speed wide area and non wide area and very fast ships, such as tankers, bulk carriers, tugboats, etc., and also to improve the flow to the propeller as well as the generation of current. , The use of the device (10) according to claim 1.

Images