JP4356092B2 - Ship with baffle plate - Google Patents

Description

  The present invention relates to a ship provided with a current plate that improves propulsion performance.

FIG. 5 is a side view of a stern portion of a conventional ship disclosed in Patent Document 1.
In this figure, 1 is a stern frame, 2 is a stern boss, which is formed in the same body as the stern frame 1 and rotatably supports a shaft 3 inserted through a front-rear-facing hole.

Reference numeral 4 denotes a rudder receiving portion formed on the rear side of the stern frame 1, which supports the rudder plate 5 so as to be swingable. A propeller 6 is fixed to the rear end of the shaft 3.
The front end of the shaft 3 is connected to a main machine (not shown).

A pair of rectifying plates 7A and 7B are fixed to the outer hull surfaces of the left and right anchors near the stern boss 2.
In each of the pair of rectifying plates 7A and 7B, the front end portions b1 and b2 excluding the rear end portions a1 and a2 are made parallel to the keel k in both the length direction and the width direction of the ship and are attached to the left and right targets. ing.

The rear end portions a1 and a2 of the pair of rectifying plates 7A and 7B are bent in the direction opposite to the forward rotation direction of the propeller 6.
That is, the rear end portion a2 of the starboard side rectifying plate 7B is bent in a rearwardly rising manner, the rear end portion a1 of the portside rectifying plate 7A is bent in a rearwardly descending manner, and the starboard side rectifying plate 7B. The rearward rising front-back inclination angle θ2 of the rear end portion a2 and the rearward downward front-back inclination angle θ1 of the rear end portion a1 of the port side rectifying plate 7A have the same size.

  Since it is configured in this manner, when the shaft 3 is rotated by the main engine installed in the ship and the propeller 6 is rotated forward, and the hull sails by the thrust generated by the propeller 6, the flow of water near the stern is It becomes very complex and flows behind the hull.

  In particular, in the vicinity of the stern boss 2, a water flow 8 from the top to the bottom and a water flow 9 from the bottom to the top merge. Here, the water flow 8 is constantly generated near the surface of the hull skin, and the water flow 9 is constantly generated at a position relatively far from the surface of the hull skin. The right and left rectifying plates 7A and 7B are installed in the merging area. In particular, the rectifying action of the front portions b1 and b2 suppresses the generation of vortices due to the merging, reduces the resistance of the hull, and improves the propulsion performance. .

Further, when the propeller 6 rotates forward and the hull sails, the rear end portions a1 and a2 of the left and right rectifying plates 7A and 7B guide water in an inclined manner so that the water rotation in the direction opposite to the forward rotation direction of the propeller 6 occurs. Create a stream.
The water rotation flow in the opposite direction reaches the front surface of the propeller 6 and is given a rotational force in the same direction as the forward rotation direction of the propeller 6 by the propeller 6 rotating forward, and the propeller 6 generated behind the propeller 6. The power of the water rotation flow in the forward rotation direction is reduced, and energy loss due to the water rotation flow behind the propeller 6 is reduced.
As a result, the energy transmitted to the propeller 6 is more effectively converted into the thrust of the propeller 6 and the propulsion performance is improved.

Japanese Utility Model Publication No. 58-63196

  In the technique shown in Patent Document 1 described above, when the action of the rear end portions a1 and a2 of each of the rectifying plates 7A and 7B is observed, on the starboard side, as shown in FIG. Then, as shown in FIG. 5B, it collides with the water flow 9 from the bottom to the top at a large angle of attack, and energy loss occurs due to a relatively large drag generated on the rectifying plates 7A and 7B, which improves the propulsion performance. It was confirmed that it was a blocking factor.

  Moreover, although the conventional baffle plates 7A and 7B are welded and fixed to the stern boss 2, there is a concern about the distortion effect of the stern boss 2 due to welding heat.

  The present invention was devised in view of the above circumstances, and includes a rectifying plate that can further improve the propulsion performance by combining the actions of each part of the rectifying plate while utilizing the advantages of the conventional technology. The purpose is to provide a ship.

In order to achieve the above object, according to the present invention, as described in claim 1, the front end portion is fixed substantially parallel to the keel at the rotation center position of the propeller on the outer surface of the left and right hulls near the stern boss. It has a baffle plate, the rear end of the rectifier plate on one side is in a back-up state so that the water flow is guided in the direction opposite to the forward rotation direction of the propeller, and the rear end portion of the rectifier plate on the other side is In a ship bent backward and downward , the flow straightening plate has a height range from the rotation center position of the propeller to a position 0.7 times the propeller radial length on the outer surface of each hull near the stern boss. The front and rear inclination angle of the rear end portion of the rectifying plate bent in the rearward direction is larger than the front and rear inclination angle of the rear end portion of the rectifying plate bent in the rearward downward direction and bent in the rearward upward direction. The rear end of the straightened current plate has a front / rear tilt angle of 30 to 40 degrees. On the other hand, wherein the rear end portion of the rectifying plate which is bent to the back edge shape is a longitudinal inclination angle of 0 to 10 degrees.

The present invention is preferably embodied as follows.
That is,
According to a second aspect of the present invention, a gap is formed between the inner edge of the rear end of the current plate on the left and right sides and the outer surface of the hull.

  According to a third aspect of the present invention, in at least one of the right and left rectifying plates, the outer edge of the rear end portion and the outer edge of the front portion are joined by a longitudinally oriented plate in the front-rear direction.

According to the present invention, the following effects can be obtained.
That is, according to the first aspect of the present invention, the rear end portion of the rectifying plate on one side corresponding to the ascending side in the direction opposite to the forward rotation direction of the propeller has a front-rear inclination angle of about 30 to 40 degrees. The rear end of the other side of the current plate corresponding to the descending side in the opposite direction is bent in a rear downward shape with a front and rear inclination angle of about 0 degrees to 10 degrees. Therefore, the power of the water rotational flow generated behind the propeller is reduced, and the energy loss is reduced as in the conventional case. At this time, the back-and-forth front and rear inclination angle of the rear end portion of the rectifying plate on one side is larger than that in the technique shown in FIGS. The back and forth tilt angle of the rear end of the rear end portion is smaller than in the case of the technique shown in FIGS. 4 to 6 of Patent Document 1, and therefore, the energy loss is reduced by the water rotation flow generated behind the propeller. Is almost the same as the case of the technique shown in FIGS.

  In addition, since the rear end portion of the other side of the rectifying plate corresponding to the descending side in the direction opposite to the forward rotation direction of the propeller has been bent in a rearward downward shape with a front-to-back inclination angle of about 0 degrees to 10 degrees, The angle of attack of the rear end of the current plate with respect to the upward flow in the region relatively far from the hull on the other side of the ship is smaller than in the case of the technique shown in FIGS. The drag force of the left and right rectifying plates as a whole is reduced, and energy loss can be suppressed.

Further, the front portions of the right and left rectifying plates suppress the generation of vortices due to merging and reduce the resistance of the hull as in the prior art.
By combining the various effects described above, it is possible to reliably improve the propulsion performance as compared with the conventional technique shown in FIGS.

Further, the following additional effects can be obtained.
In other words, the front side of the rectifying plate is keel within the height range from the center of rotation of the propeller to the position approximately 0.7 times the propeller radial length on the outer surface of the left and right hulls near the stern boss. And the rear end of the rectifying plate on one side corresponding to the rising side in the direction opposite to the forward rotation direction of the propeller is raised to a back and forth inclination angle of about 30 to 40 degrees. And the rear end portion of the other side of the rectifying plate corresponding to the descending side in the opposite direction is bent in a rear downward shape with a front and rear inclination angle of about 0 degrees to 10 degrees. From the conventional technology shown in FIGS. 4 to 6 of Patent Document 1, the force of the upward flow from around the stern boss toward the top of the propeller becomes stronger, and the action of accelerating the slow flow at the top of the propeller is obtained. Yes, this action is during forward rotation of the propeller Reduce the variation of the thrust and torque, it becomes to suppress the hull vibration caused by this variation.

  According to the second aspect of the present invention, it is not necessary to weld the rear end portion of the current plate to the stern boss. Therefore, the influence of the welding heat of the stern boss is reduced, and the quality can be maintained well, and welding is performed. Can be reduced. In addition, the downward flow of the hull surface passes through the gap between the rear end of the rectifying plate and the hull surface, so that the drag of the rectifying plate due to the downward flow can be reduced and the propulsion performance is further improved. be able to.

  According to the third aspect of the present invention, the rigidity of the rectifying plate can be increased by the vertically oriented plate, and the rectifying effect of the rectifying plate can be enhanced by suppressing three-dimensional separation from the outer edge of the rectifying plate. The propulsion performance can be further improved.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a stern part of a ship according to an embodiment of the present invention, in which A is a right side view, B is a left side view, FIG. 2 is a plan view of the stern part, and FIG. FIG. 4 is a perspective view showing a modified example of the stern part.

  As shown in FIG. 1 and FIG. 2, the rectifying plates 7A and 7B on the left and right sides are made of a single flat plate member made up of front end portions b1 and b2 and rear end portions a1 and a2, as in the prior art. Front portions (horizontal portions parallel to the keel k) b1 and b2 are on the outer surface of the hull in front of the stern boss 2 and at a position approximately 0.7 times the propeller radial length from the rotation center position of the propeller 6. The inner edges c1 and c2 are fixed to the outer surface of the hull by welding, and the rear ends a1 and a2 are arranged on the side of the stern boss 2 and the inner edge d1. , D2 and the hull are formed with a gap e, which is coupled to and supported by the hull via the front portions b1 and b2.

  At this time, the rear ends a1 and a2 have a length corresponding to the stern boss 2. For example, the front end is positioned at the front end of the stern boss 2 or the front end thereof, and the rear end is the rear end of the stern boss 2. Reach nearby.

  The forward rotation direction of the propeller 6 is a backward clockwise direction, and, as shown in FIG. 1A, the starboard rectifying plate 7B that forms one side corresponding to the rising side opposite to the forward rotation direction. The rear end portion a2 is bent upward so as to form a front / rear inclination angle θ2 of about 30 to 40 degrees.

  Therefore, when the propeller 6 rotates forward and the hull moves, the rear end portion a2 of the starboard side rectifying plate 7B guides water rearward and upward to generate a water rotational flow in a direction opposite to the propeller forward rotational direction. Contributes above. At this time, the fact that the back-and-forth back-and-forth inclination angle θ2 is about 30 to 40 degrees works extremely effectively in generating a water rotation flow in a direction opposite to the propeller forward rotation direction.

  The rear end portion a1 of the left side rectifying plate 7A corresponding to the descending side opposite to the forward rotation direction of the propeller 6 is lowered after forming a front and rear inclination angle θ1 of about 0 ° to 10 °. It is bent into a shape.

  Therefore, when the propeller 6 rotates forward and the hull sails, the rear end a1 of the port side rectifying plate 7A guides the water horizontally backward or slightly rearward and downward in the direction opposite to the propeller forward rotation direction. This contributes to the generation of water rotation.

  At this time, the fact that the back and forth tilt angle θ1 is about 0 ° to 10 ° indicates that the water rotation flow in the opposite direction to the propeller forward rotation direction is compared to the case where this is about 30 ° to 40 °. As a result, the effect of reducing the energy loss due to the suppression of the water rotation flow behind the propeller 6 is less than the case where the back-and-forth front-back inclination angle θ1 is, for example, about 30 to 40 degrees. descend.

  However, as compared with the prior art shown in FIGS. 4 to 6 of Patent Document 1, the front / rear inclination angle θ2 of the starboard side rectifying plate 7B is made larger than that of the prior art, while the starboard side rectifying plate 7A. Since the front and rear inclination angle θ1 is smaller than that of the conventional technique, the effect of generating the water rotation flow in the direction opposite to the propeller forward rotation direction is not much different from that of the conventional technique. The effect of reducing the energy loss due to the suppression of the water rotation can be almost the same.

  On the other hand, the fact that the rearwardly inclined front and rear inclination angle θ1 is about 0 ° to 10 ° indicates that the rear end portion a1 on the port side rectifying plate 7A is higher than that in the case where this is about 30 ° to 40 °. It collides with the water flow 8 going downward from the water at a relatively small angle of attack, and contributes to reducing the drag of the rear end a1 due to this water flow.

  As described above, the drag of the rear end a1 is reduced by the rearwardly inclined front / rear inclination angle θ1 being about 0 ° to 10 °, even if the front / rear inclination angle θ1 is about 0 ° to 10 °. Even if there is a reduction in the energy loss reduction effect due to the suppression of the water rotation flow behind the propeller 6, it contributes to improving the propulsion performance when the functions of the left and right rectifying plates 7A and 7B are combined. To be.

  Further, a gap e formed between the rear end portions a1 and a2 of the left and right rectifying plates 7A and 7B and the outer surface of the hull makes the water flow 8 from the upper side to the lower side of the left and right sides around the stern boss 2 near the hull outer surface. This contributes to the flow of the current plates 7A and 7B so that they can pass without colliding with the rear ends a1 and a2 of the current plates 7A and 7B. The propulsion performance is further improved by being relatively small.

  Further, in particular, the front portions b1 and b2 of the right and left rectifying plates 7A and 7B are, as in the prior art shown in FIGS. 4 to 6 of Patent Document 1, a water flow 8 from the top to the bottom and a water flow from the bottom to the top. It is located in the merging area of 9 and rectifies these water streams so as to guide them backward, thereby suppressing the generation of vortices and reducing the resistance of the hull.

  The pair of left and right rectifying plates 7A and 7B of the present embodiment described above has the same angle in the direction opposite to the propeller forward rotation direction with respect to the rear end portions a1 and a2 of the respective rectifying plates 7A and 7B due to the synthesis of the operations of the respective portions described above. The propulsion performance is surely improved as compared with the conventional technique shown in FIGS.

  Further, the pair of left and right rectifying plates 7A and 7B are positioned within a height range from the rotation center position of the propeller 6 to a position approximately 0.7 times the propeller radial length, and the propeller 6 is moved forward. Bend the rear end portion a2 of the starboard rectifying plate 7B, which forms one side corresponding to the rising side in the direction opposite to the rotation direction, in a rearward rising shape with a front-rear inclination angle θ2 of about 30 ° to 40 °, and Since the rear end part a1 of the left side rectifying plate 7A that forms the other side corresponding to the descending side in the opposite direction is bent in a rearward downward direction with a front-rear inclination angle θ1 of about 0 degrees to 10 degrees, Compared with the prior art shown in FIGS. 4 to 6 of Patent Document 1 in which the current plate 7A, 7B is positioned below the stern boss 2, the force of the upward flow toward the upper portion of the propeller 6 becomes stronger.

  In general, the upper part of the propeller 6 has a slower flow than the surrounding area, and when the propeller 6 is driven to rotate in a region where the flow is slow, fluctuations in thrust and torque of the propeller 6 become large, and vibrations caused by this increase. It may be transmitted to the hull and cause hull vibration.

  However, as described above, the force of the upward flow toward the top of the propeller 6 is strengthened by the left and right rectifying plates 7A and 7B, whereby the slow flow at the top of the propeller 6 is accelerated, and the propeller 6 is rotationally driven in the fast flow. The thrust and torque fluctuations are reduced. As a result, the generation of hull vibration due to the thrust and torque is suppressed.

  Further, the rear end portions a1 and a2 of the left and right rectifying plates 7A and 7B do not need to be welded to the stern boss 2, so that the thermal effect and welding labor caused by welding to the stern boss 2 are reduced.

  FIG. 3 shows a result of an experiment by a model ship for each of the ship not provided with the current plate, the ship provided with the current plate shown in FIGS. 4 to 6 of Patent Document 1, and the ship according to the present invention.

  FIG. 3A is a comparison of the additive effect and shows that the resistance of the ship according to the present invention is reduced by about 2% to 3% compared to that of the other.

  FIG. 3B compares the hull efficiency proportional to the propulsion performance. The hull efficiency of the ship according to the present invention is more reliable than that of the ship including the current plate shown in FIGS. It shows that it becomes larger.

  FIG. 4 shows a modification of the above embodiment. The outer edge of the rear end portion a2 of the starboard side rectifying plate 7B and the outer edge of the front end portion b2 are connected by a longitudinal plate 10 in the front-rear direction. In this way, the rigidity of the rectifying plate 7B is increased, and three-dimensional separation from the outer edge of the rectifying plate 7B is suppressed, the rectifying effect in the front-rear direction is improved, and the drag of the rectifying plate 7B is reduced.

  When the rear end portion a1 of the port side rectifying plate 7A is bent rearward and downward, the outer edge and the front portion b1 of the rear end portion a1 of the rectifying plate 7A are conformed to the starboard side rectifying plate 7B. It is also possible to join the outer edges of the two with a longitudinal plate in the front-rear direction.

1 shows a stern part of a ship according to an embodiment of the present invention, in which A is a right side view and B is a left side view. It is a top view of the stern part. It is a figure which shows an experimental result. It is a perspective view which shows the modification of the said stern part. The stern part of the ship of a prior art example is shown, A is a right view and B is a left view.

Explanation of symbols

2 Stern boss 6 Propeller 7A Rectifying plate 7B Rectifying plate 10 Vertically oriented plate a1 Rear end portion a2 Rear end portion b1 Front side portion b2 Front side portion c1 Inner edge c2 Inner edge e Gap k Keel θ1 Front and rear tilt angle θ2

Claims (3)

It has a baffle plate with the front end fixed in parallel to the keel at the center of rotation of the propeller on the outer surface of the left and right hulls near the stern boss, and guides the water flow in the direction opposite to the propeller's forward rotation direction. In a ship where the rear end of the rectifier plate on one side is bent upwards and the rear end of the rectifier plate on the other side is bent downwardly ,
The rectifying plate is provided in a height range from the rotation center position of the propeller to a position 0.7 times higher than the propeller radial length on the outer surface of each hull near the stern boss,
The front / rear inclination angle of the rear end portion of the rectifying plate bent upwardly is larger than the front / rear inclination angle of the rear end portion of the rectifying plate bent downwardly, and is behind the rectifying plate bent upwardly. An end portion has a front / rear inclination angle of 30 ° to 40 °, and a rear end portion of the current plate bent in a rearwardly descending manner has a front / rear inclination angle of 0 ° to 10 °. Ship equipped.   The ship provided with the current plate according to claim 1, wherein a gap is formed between the inner edge of the rear end portion of the current plate on each of the left and right sides and the outer surface of the hull.   The rectifying plate according to claim 1 or 2, wherein at least one of the rectifying plates on each of the left and right sides, the outer edge of the rear end portion and the outer edge of the front end portion are coupled by a longitudinally oriented plate in the front-rear direction. Ship.

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