JP3886049B2 - Valve, rudder, ship - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a valve provided at a position facing a propeller in a rudder for improving propulsion efficiency of a ship, a rudder provided with the valve, and a ship provided with the rudder.
[0002]
[Prior art]
Various measures are taken to improve the propulsion efficiency of the ship in the propeller and the rudder around the ship. One of them is a valve, and the valve is provided at a position facing the propeller in the rudder, so that the wake of the propeller is excluded to the outside and the inflow speed of the wake that flows into the propeller is slowed down. Propulsion efficiency is improved (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 9-11990
[Problems to be solved by the invention]
Here, while the valve increases the propulsion efficiency by slowing the inflow speed of the wake that flows into the propeller, on the other hand, the valve itself generates drag and contributes to lowering the propulsion efficiency. An important issue is whether to take it.
[0005]
The conventional valve is formed so as to have a vertically symmetrical shape (so-called rotating body shape) around the rotation axis when viewed from the direction of the rotation axis of the propeller. However, from the viewpoint of the balance described above, It was not an ideal shape.
[0006]
Therefore, the present invention further improves the balance by forming a valve shape that is more balanced from the viewpoint of the merit of the valve that slows the inflow speed of the wake that flows into the propeller and the disadvantage that the valve itself generates drag. It is to improve propulsion efficiency.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, a first aspect of the present invention is a valve provided on an extension line of a rotation axis of a propeller at a position facing a propeller in a rudder of a ship, the rotation axis The shape in a direction view is formed such that the area of the lower region is larger than the area of the upper region with respect to the horizontal line intersecting the rotation axis of the propeller.
[0008]
In the range in which the valve is provided in the wake distribution of the propeller wake (when the propeller is operating), there is a region where the flow is fast from the propeller rotation axis to the upper portion. That is, it is an area where the propulsion efficiency is easily lowered. On the other hand, in the wake distribution of the hull wake flowing into the propeller, there is a fast flow region below the propeller rotation axis, so the propeller inflow speed of the region is slowed by the valve, and the propeller The wake gain can be effectively improved. Therefore, in the first aspect, in view of such a flow distribution, the valve shape is made smaller in the region above the propeller rotation axis and lower than the propeller rotation axis when viewed in the direction of the propeller rotation axis. Increased the area. As a result, the drag by the valve is reduced, and the wake that flows into the propeller can be effectively excluded to the outside of the propeller rotation surface to improve the propulsion efficiency.
[0009]
According to a second aspect of the present invention, in the first aspect, the lower region is formed by a true arc, and the upper region is formed by an elliptical arc.
According to the second aspect, since the lower region is formed by a true arc and the upper region is formed by an elliptical arc, the area of the lower region from the propeller axis of rotation of the valve in the direction of the propeller axis is shown. Becomes larger than the area of the upper region, whereby the operational effect of the first aspect described above can be obtained.
[0010]
According to a third aspect of the present invention, in the first aspect, the lower region is formed by a true arc, the lower region has two straight lines connected to two end points of the true arc, and the 2 It is formed by a true arc connected to the end points of two straight lines.
[0011]
According to the third aspect, the lower region is formed by a true arc, and the lower region is connected to two straight lines connected to the two end points of the true arc and the end points of the two straight lines. As a result, the area of the lower region from the propeller axis of rotation of the valve in the direction of the propeller axis of the valve is larger than the area of the upper region. Can be obtained.
[0012]
According to a fourth aspect of the present invention, there is provided a rudder provided in a ship, wherein the valve described in any one of the first to third aspects is provided at a position facing the propeller. . According to the fourth aspect, it is possible to obtain the same effect as any one of the first to third aspects.
[0013]
A fifth aspect of the present invention is a ship provided with the rudder of the fourth aspect. Also according to the fifth aspect, it is possible to obtain the same effects as any of the first to third aspects.
[0014]
A sixth aspect of the present invention is characterized in that, in the fifth aspect, a propeller cap provided at a position facing the valve is formed so that a diameter increases sequentially toward the valve. To do.
According to the sixth aspect, since the propeller cap provided at a position facing the valve is formed so that the diameter gradually increases toward the valve, the shape of the propeller is increased by such a shape. It can diffuse and rectify turbulent flows and vortices generated in the rear center.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
First, an embodiment of a valve according to the present invention will be described with reference to FIGS. Here, FIG. 1 is a stern side view, FIG. 2 is a wake distribution diagram of the propeller wake (when the propeller is operating), FIG. 3 is a circumferential distribution diagram of the wake coefficient of the propeller wake (when the propeller is operating), and FIG. Is a circumferential distribution diagram of the wake coefficient at the propeller position of the hull wake flowing into the propeller, FIG. 5 is a front view of the valve 13, FIG. 6A is a plan view of the valve 13, and FIG. 13 is a front view of the valve 14, FIG. 8A is a plan view of the valve 14, and FIG. 8B is a side view of the valve 14 (viewed from the starboard side). FIG. 9 is a diagram showing the difference between the self-propelled elements of the present invention and the conventional example.
[0016]
In FIG. 1, a rudder 9 is provided via a rudder shaft 11 behind a propeller 3 provided at the stern portion of the hull 1. The propeller 3 is provided so as to be rotationally driven about the rotation axis C, and a propeller cap 7 is attached to the tip of the propeller labs 5 (the side facing the rudder 9) constituting the rotation center portion of the propeller 3. ing. Further, a valve 13 is provided at a position in the rudder 9 that faces the propeller 3 and intersects the rotation axis C of the propeller 3. The valve 13 is intended to improve the wake gain in the propeller 3 by forming a flow area having a large wake coefficient in the rotating surface of the propeller 3 by blocking the wake flowing into the propeller. In addition, the line shown by code | symbol AP shows the rotating shaft core line of the rudder 9. FIG.
[0017]
The propeller cap 7 is formed in a shape that gradually increases in diameter toward the valve 13 (in this embodiment, a conical shape), and is configured to improve propulsion efficiency. That is, a so-called hub vortex is generated when the hull 1 sails behind the propeller labs 5 and disturbs the flow. However, by forming the propeller cap 7 in the conical shape as described above, Makes it possible to diffuse the hub vortex to the outside of the valve 13 and rectify the flow turbulence caused by the hub vortex.
[0018]
Next, the wake of the propeller 3 will be described with reference to FIGS. In FIG. 2, the symbol V indicates a vertical line intersecting with the rotation axis of the propeller 3, the symbol H similarly indicates a horizontal line intersecting with the rotation axis of the propeller 3, and the symbol PD indicates a propeller rotation surface. As shown in the drawing, the wake distribution of the propeller wake is a region below the horizontal line H, more specifically, in a range where the valve is provided in the propeller rotation surface PD (approximately the range of a circle indicated by reference sign PC). A state in which the flow is slow in the region below the horizontal line H and close to the rotational axis of the propeller 3 (the wake coefficient is large), and the flow in the region above the horizontal line H is fast (the wake coefficient is small). It has become.
FIG. 3 shows this state as a circumferential distribution of wake coefficients. In FIG. 3, 0 ° and 180 ° correspond to the vertical line V, and 90 ° and 270 ° correspond to the horizontal line H. As shown in the drawing, the wake coefficient is smaller in the range above the horizontal line H (270 ° to 90 °) than in the range below (90 ° to 270 °) (the flow is faster). ).
[0019]
On the other hand, in FIG. 4 showing the wake coefficient circumferential distribution of the hull wake flowing into the propeller 3, 0 ° and 180 ° represent the vertical line V, and 90 ° represents the horizontal line H. In FIG. 4, there is a region with a small wake coefficient (fast flow) in a region below the horizontal line H. That is, it can be seen that by providing the valve 13, the inflow speed of the hull wake flowing into the propeller 3 can be slowed, and thus the wake gain in the propeller 3 can be effectively improved.
[0020]
2 and FIG. 3, the region above the horizontal line H greatly contributes to the generation of drag due to the shape of the valve 13, and exhibits the damming effect of the wake that flows into the propeller 3. It can be seen that the effect of reduction in propulsion efficiency due to the generation of drag tends to be more significant than the effect of improving flow gain. On the other hand, it can be seen from FIG. 4 that the area below the horizontal line H can effectively improve the wake gain in the propeller 3 when the valve 13 exerts the weir effect of the propeller wake.
[0021]
Therefore, in the present embodiment, the shape of the valve 13 viewed in the direction of the propeller axis is made asymmetrical with respect to the horizontal line H as shown in FIG. 5, and the area of the lower region is larger than the area of the upper region above the horizontal line H. It was formed so as to be larger (formed so that the area of the upper region was smaller than the area of the lower region from the horizontal line H). In other words, the area of the upper region that greatly contributes to the generation of drag due to the shape of the valve 13 is small, and the area of the lower region that can effectively obtain the weir effect of the wake of the propeller is large, so that the propulsion efficiency Can be improved effectively.
[0022]
As a specific example, the shape of the valve 13 can be formed by an elliptical arc 13a in which the lower region from the horizontal line H is connected by a true arc 13b and the upper region is connected to the end point of the true arc. Further, as shown in FIGS. 6A and 6B, it is preferable to form a streamline shape in plan view and side view from the viewpoint of preventing flow separation. Further, as another embodiment, a front shape as shown in FIG. 7 and 8 show a valve 14 according to another embodiment. The valve 14 has a lower region formed by a true arc 14c in a front view and an upper region a straight line 14b connected to the true arc. , 14b and an arc 14a connected to the straight lines 14b, 14b.
[0023]
The shape of the valve described above is an example, and the shape of the lower region from the rotation axis of the propeller 3 is larger than the area of the upper region (the shape of the upper region is smaller than the area of the lower region). Any shape can be used.
[0024]
FIG. 9 shows a case without a valve, a valve according to the prior art (a circular shape symmetrical in the vertical direction (so-called rotating body shape) in the direction of the rotation axis of the propeller 3), valves 13 and 14 according to the present embodiment, It is a figure which shows the self-propelled element. In the figure, “asymmetric valve A” indicates the valve 13, “asymmetric valve B” indicates the valve 14, η _R is the propeller efficiency ratio, 1-t is 1-t based on the propulsion reduction coefficient t, and 1-w _S is a model. 1-w _S based on the actual ship wake coefficient w _S estimated based on the ship wake coefficient, Δη is the propulsive efficiency η _P (= ((1-w _S ) / (1-t)) * (eta) _R * (eta) _O : (eta) _O shows the improvement rate of propeller independent efficiency. As shown, an asymmetric valve A, B are both according to prior art compared to the valve 1-w decreases, whereby it can be seen that the propulsion efficiency eta _P is improved greatly.
[0025]
Next, fins attached to the rudder 9 will be described with reference to FIGS. 10 to 16. Here, FIG. 10 is a flow velocity distribution diagram in a plane perpendicular to the propeller shaft center around the rudder (rudder section) when the propeller is operated (clockwise), and FIGS. 11A and 11B are perspective views of the rudder. 12 is a side view of the stern part, FIG. 13 is a diagram showing a self-propelled element when fins are provided only on the starboard, only on the starboard, and on both the port and starboard, and FIG. 14 is a relationship between the span of the starboard fin and the self-propelled element. FIG. 15 is a front view of the stern part, and FIG. 16 is a view showing the cross-sectional shape (wing shape) of the fins.
[0026]
By attaching the fin rudder 9, to generate lift and drag by the propeller slipstream, the propulsion direction component in the resultant force of該揚force and drag it possible to improve the propulsion efficiency eta _P to recover rotational flow of the propeller 3 it can. Hereinafter, specific embodiments of the fin will be described.
[0027]
First, FIG. 10 is a vector diagram showing the flow direction of the propeller wake in the cross section of the rudder 9 (viewed from the rear of the hull). Since the propeller 3 rotates to the right when viewed from the rear of the hull, the wake generated only by the propeller 3 is an upward flow on the port side of the rudder 9 and a downward flow on the starboard side. However, the propeller 3 is a vortex in the clockwise direction in FIG. 2 on the port side of the rudder 9 from the hull 1 and in the counterclockwise direction on the starboard side, that is, a vortex generated from the hull 1 by the propulsion of the hull 1. 3, a vortex (so-called bilge vortex) that flows upward at the outer periphery of the propeller rotation surface PD on the left and right sides of the rotation axis of the propeller 3 and flows downward toward the rotation axis of the propeller. Flows in (see FIG. 11). Therefore, due to these canceling effect and synergistic effect, as shown in FIG. 10, a slow random flow field (slow flow) is generated in the vicinity of the rudder side surface on the port side, and abrupt in the outer peripheral portion of the propeller rotating surface PD. An upward flow field is generated. On the starboard side, a steep downward flow field (rapid flow) is generated in the vicinity of the rudder side surface.
[0028]
As described above, when the fin is attached to the rudder 9, the fin attached to the port side needs to be sufficiently extended to the outer peripheral portion of the propeller rotation surface PD so as to reach the above-described steep upward flow field. In this case, however, the fins must pass through a slow random flow field near the left side of the rudder 9.
[0029]
Here, in the slow random flow field in the vicinity of the left side surface of the rudder 9, the fin cannot exhibit sufficient lift, and the drag becomes dominant, rather, the propulsion efficiency (hereinafter represented by the symbol η _P ) is reduced. It is easy to cause. Further, the allowable range of the fin mounting conditions such as the fin mounting position or mounting angle that can improve the propulsion efficiency η _P is extremely narrow, and the adjustment work is likely to be extremely difficult. In most cases, the optimum fin attachment conditions cannot be obtained as a result in all the navigation conditions of the ship, and the propulsion efficiency η _P is reduced by attaching the fins.
[0030]
Therefore, to avoid reliably slow random flow field generated in the vicinity of the side surface of the port side of the rudder 9 described above, by providing the fins only starboard side of the rudder 9, reliably eliminate the reduction factors of propulsion efficiency eta _P Te, it is possible to improve the propulsion efficiency eta _P efficiently.
[0031]
FIG. 13 is a diagram comparing the self-propelled elements when fins are provided only on the port side, only on the starboard side, and on both the port side and starboard side (the fin span is 35% of the propeller diameter Dp for both the starboard side and the port side). . As shown in the figure, it can be seen that the propulsion efficiency η _P when fins are provided only on the starboard is improved as compared to the propulsion efficiency η _P when fins are provided on both sides (in particular, 1-t is Significantly improved). In other words, it is understood that the port fin becomes a factor of lowering the propulsion efficiency eta _P.
[0032]
Next, FIG. 14 shows changes in the self-propelled element when the span of the starboard fin (ratio to the propeller diameter Dp) is changed from 0% (no fin) to 20%, 28%, and 35%. As shown in the figure, it can be seen that as the fin span is increased, the propulsion efficiency η _P increases in proportion to the fin span up to 35% (particularly, 1-t is significantly improved).
[0033]
On the other hand, if the fins protrude outward from the propeller rotation surface, the fins exist in the range where the propeller rotation flow does not exist, and it is considered that the drag is dominant and the propulsion efficiency η _P decreases. The propeller wake is contracted because it is accelerated by the propeller, and the range where the propeller rotating flow exists is actually narrower than the propeller rotating surface.
As described above, the function of the starboard fin can be effectively exhibited by setting the span of the starboard fin to be at least about 20% to 45% of the propeller diameter.
[0034]
Next, FIGS. 11 and 12 show an embodiment of a starboard fin. In any of the rudder 9 shown in FIGS. 11 and 12, no fin is provided on the port side, and the side surface on the starboard side. Fins 15a are provided only on 9a. FIG. 11A shows an embodiment in which the fins 15a are directly attached to the side surface 9a, and FIGS. 11B and 12 show an embodiment in which the fins 15a are attached to the valve 12. FIG.
[0035]
Similarly to the valves 13 and 14 described with reference to FIGS. 5 to 8, the valve 12 has a shape that is vertically asymmetric with respect to the propeller rotation axis, and the propeller rotation axis is more to the area of the upper region, that is the area of the lower region is formed as a large becomes, can be improved even more propulsion efficiency eta _P as described above. However, even if it is a vertically symmetrical valve shape (so-called rotating body shape), it is possible to obtain the effect of the fin 15a only on the starboard side described above.
[0036]
In addition, the following effects can be obtained. FIG. 15A is a view showing a state where fins are attached to the left and right sides of the rudder 9 (reference numeral 15b is a port side fin), and FIG. 15B is a view showing a state where fins 15a are attached only to the starboard. It is. When fins are attached to the left and right sides, lift is generated in the direction indicated by the arrows in the figure. Here, the respective lift forces give a rotating moment in the clockwise direction in the figure to the rudder shaft 11 or the rudder 9 body of the rudder 9, and it is necessary to consider this in the strength design of the rudder shaft 11 or the rudder 9. . However, by attaching the fins 15a only to the starboard, the rotational moment can be reduced, whereby the strength considered in the design of the rudder shaft 11 or rudder 9 can be set low, and the degree of freedom in design The cost of the rudder shaft 11 or rudder 9 can be reduced by simplifying the structure and the like.
[0037]
Next, the airfoil of the fin 15a in this embodiment will be described in detail. As shown in FIG. 12, the fins 15a can be formed in an airfoil shape. In this case, the starboard-side fins 15a are provided so that the camber line protrudes downward (in the case of being provided on the port side, the upper side). To be convex.) FIG. 15 is a view showing the airfoil of the fins 15a so that the camber line is convex upward for the convenience of explanation, and the symbol CB indicates the camber line. In FIG. 15, in the present embodiment, the maximum thickness d in the blade cross-sectional shape is set to be 5% to 25% of the blade saddle length a + b. Therefore, it is possible to keep the increase in drag constant while obtaining a certain camber so as to reliably obtain lift. Further, the position Q of the maximum thickness d is set to an arbitrary position (distance indicated by the symbol e) of 45% to 50% of the chord length from the blade leading edge. Accordingly, the distribution of the blade thickness is uniform before and after, and the decrease in blade strength can be prevented.
[0038]
Furthermore, on the side opposite to the convex side (blade bottom surface), the straight line between the blade trailing edge and an arbitrary position P from 45% to 55% of the chord length from the blade trailing edge (section indicated by symbol b) is a straight line. It is formed to be a (flat surface) (straight line G). Therefore, the workability of the fin is excellent, and the cost of the fin can be reduced. In addition, the section from the terminal position of the straight line to the blade leading edge (section indicated by symbol a) is a curve (curve F) located on the blade thickness increasing direction side with respect to the extension line of the straight line. The maximum distance (the distance indicated by the symbol c) between the straight line extension line and the extension line is less than 5% of the chord length a + b. Therefore, the camber can be sufficiently obtained in the front half of the blade where the blade effect can be effectively obtained.
[0039]
Such a shape of the airfoil is not limited to the embodiment in which fins are attached only to the starboard side of the rudder 9, and the above-described effects can be obtained also in the embodiment in which fins are attached to both sides of the rudder 9. Needless to say.
[0040]
【The invention's effect】
As described above, according to the present invention, in view of the flow distribution in the range where the valve is provided (in the propeller cap surface) and the flow distribution in the entire propeller rotation surface, the valve shape is changed to the propeller rotation axis. In the direction view, the area above the propeller rotation axis is made smaller and the area below the propeller rotation axis is made larger. This reduces the drag force caused by the valve and effectively prevents the propeller from flowing into the propeller. It is possible to improve the propulsion efficiency by removing it outside the rotating surface.
[Brief description of the drawings]
FIG. 1 is a stern side view of a ship according to the present invention.
FIG. 2 is a wake distribution diagram of the propeller wake (when the propeller is operated).
FIG. 3 is a circumferential distribution diagram of a wake coefficient of a propeller wake (when a propeller is operated).
FIG. 4 is a circumferential distribution diagram of the wake coefficient at the propeller position of the hull wake flowing into the propeller.
FIG. 5 is a front view of a valve according to the present invention.
6A is a plan view of a valve according to the present invention, and FIG. 6B is a side view thereof.
FIG. 7 is a front view of a valve according to the present invention.
8A is a plan view of a valve according to the present invention, and FIG. 8B is a side view thereof.
FIG. 9 is a diagram showing a difference in self-propelled elements between a valve according to the present invention and a valve according to a conventional example.
FIG. 10 is a flow velocity distribution diagram in a plane perpendicular to the propeller shaft core around the rudder (rudder cross section) when the propeller is operated (clockwise).
11A is an external perspective view of a rudder, and FIG. 11B is an external perspective view of a rudder according to another embodiment.
FIG. 12 is a side view of the stern part.
FIG. 13 is a diagram showing each self-propelled element when fins are provided only on the starboard side, only on the starboard side, and on both sides.
FIG. 14 is a diagram illustrating a relationship between a span of a starboard fin and a self-propelled element.
FIG. 15 is a front view of the stern part.
FIG. 16 is a diagram showing a cross-sectional shape (blade cross-section) of a fin.
[Explanation of symbols]
1 Hull 3 Propeller 5 Propeller Labs 7 Propeller 7a Propeller Cap 9 Rudder 11 Rudder Shaft 13, 14 Valve 15a Fin (Starboard Side)

Claims (6)

A valve provided on the extension line of the rotation axis of the propeller at a position facing the propeller in the rudder of the ship,
2. The valve according to claim 1, wherein the shape of the rotation axis when viewed from the direction of the rotational axis is formed such that the area of the lower region is larger than the area of the upper region with respect to the horizontal line intersecting the rotation axis of the propeller. In claim 1, the lower region is formed by a true arc,
The upper region is formed by an elliptical arc;
A valve characterized by that. In claim 1, the lower region is formed by a true arc,
The lower region is formed by two straight lines connected to the two end points of the true arc and a true arc connected to the end points of the two straight lines.
A valve characterized by that. A rudder provided in a ship, wherein the valve according to any one of claims 1 to 3 is provided at a position facing a propeller.
Rudder characterized by that. A ship comprising the rudder according to claim 4. In claim 5, the propeller cap provided at a position facing the valve is formed so that the diameter gradually increases toward the valve.
A ship characterized by that.

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