JP6689736B2 - Fin unit device and ship equipped with the same - Google Patents

Description

  The present invention relates to a fin unit device for improving a flow field on the upstream side of a propeller and a ship equipped with the fin unit device.

In order to improve the propulsion performance of a ship, it is known to provide a fin unit on the upstream side of the propeller that induces a swirling flow in the direction opposite to the propeller (see Patent Documents 1 and 2).
Further, Patent Document 3 discloses a configuration in which a cylindrical front nozzle fixed to bossing is provided so that an external fin protrudes outward. Furthermore, it is described that the pre-vortex can be optimized by having different angles of attack for the outer fin and the inner fin.

Japanese Patent No. 5281559 Japanese Patent No. 5901512 Japanese Patent No. 5357319 (paragraph [0033])

  However, although the above Patent Document 3 discloses that the angles of attack of the external fins and the internal fins are different, the flow field on the upstream side of the propeller is complicated and the flow direction is different at each position. The angle of attack determined by the installation angle is not uniformly determined. That is, if the fins are installed at different positions, the angles of attack of the fins are different even if the fin installation angles are the same. Therefore, the matter of disposing the fins at different angles of attack disclosed in Patent Document 3 does not make a technical sense and does not indicate a concrete problem solving means.

  The present invention has been made in view of the above circumstances, and provides a fin unit device capable of improving the flow field on the upstream side of a propeller to improve the propulsion performance of the ship, and a ship including the fin unit device. The purpose is to

  In order to solve the above problems, a fin unit device of the present invention and a ship equipped with the fin unit device employ the following means.

  The fin unit device of the present invention is located in front of the propeller ship, and has a duct fixed to the bossing side so as to surround the rotation axis of the propeller, and an outer end portion fixed to the inner peripheral side of the duct, Inner fins that extend substantially inward in the radial direction toward the axis of rotation, and are located in the extending direction of the inner fins, and have inner ends fixed to the outer peripheral side of the duct and extending substantially outward in the radial direction. At least a pair of the inner fin and the outer fin, the propeller is on the port side when the propeller is rotating right when viewed from the rear of the ship, or when the propeller is rotated left when viewed from the rear of the ship. On the starboard side, the angle of attack is formed with respect to the inflowing water, the installation angle of the inner fin with respect to the reference plane including the rotation axis is θi, and the installation angle of the outer fin with respect to the reference plane is θo. In this case, θi> θo.

An inner fin and an outer fin fixed to a duct located in front of the propeller ship promotes pre-turning upstream of the propeller to improve propeller efficiency.
Since the inner fins and the outer fins are fixed to the duct, even if the inner fins and the outer fins have different installation angles, they can be easily installed through the duct.
The upstream side of the propeller has a complicated flow field due to the hull shape such as bossing. For example, in a plane orthogonal to the propeller rotation axis, the flow from the upper side to the lower side is mainly on the inner peripheral side around the propeller rotation axis, and the flow from the lower side to the upper side is mainly on the outer peripheral side along the circumferential direction. Becomes The present inventors have paid attention to this flow field and found that the installation angles of the inner fins and the outer fins can be optimized.
Specifically, in the case of propeller clockwise rotation, on the port side (in the case of propeller counterclockwise rotation, the starboard side), an angle of attack is formed with respect to the inflowing water, and the inner fin of the reference plane including the axis of rotation is When the installation angle is θi and the installation angle of the outer fin with respect to the reference plane is θo, the relationship of θi> θo is established. The reason for this is as follows.
On the port side in the case of right-hand rotation of the propeller (on the starboard side in the case of left-hand rotation of the propeller), the flow field on the inner peripheral side is mainly the flow from the upper side to the lower side, and the direction opposite to the propeller rotating from the lower side to the upper side. Become. Therefore, it is preferable to increase the installation angle θi of the inner fin so as to promote the flow from the upper side to the lower side.
On the other hand, the flow field on the outer peripheral side is mainly a flow from the lower side to the upper side, and is in substantially the same direction as the propeller rotating from the lower side to the upper side. Therefore, it is preferable that the outer fin has an installation angle that changes the flow downward. However, on the outer peripheral side, the flow velocity in the direction of the propeller rotation axis is higher than on the inner peripheral side. Therefore, it is not preferable to set the installation angle of the outer fins so as to obtain a large angle of attack, because the outer fins resist the flow. Therefore, the installation angle θo of the outer fin is set smaller than the installation angle θi of the inner fin (θi> θo).
As described above, the flow field on the upstream side of the propeller is improved on the inner peripheral side and the outer peripheral side, and the propulsive performance of the ship can be improved.
When the inner fins and the outer fins have a wing shape, it is preferable to install the wing shape with the ventral side facing downward. This makes it possible to effectively change the flow direction from the upper side to the lower side by utilizing the ventral shape.

  Further, the fin unit device of the present invention is located in front of the propeller ship, and has a duct fixed to the bossing side so as to surround the rotation axis of the propeller, and an outer end portion fixed to the inner peripheral side of the duct. , An inner fin extending substantially inward in the radial direction toward the rotation axis, and an inner end portion fixed to the outer peripheral side of the duct while being located in the extending direction of the inner fin, and being substantially outward in the radial direction. At least a pair of the inner fins and the outer fins, which extend with an outer fin, extend to the starboard side when the propeller rotates to the right when viewed from the rear of the ship, or the propeller rotates to the left when viewed from the rear of the ship. In this case, on the port side, an angle of attack is formed with respect to the inflowing water, the installation angle of the inner fin with respect to the reference plane including the rotation axis is θi, and the installation angle of the outer fin with respect to the reference plane is θi. If o, then θi <θo.

An inner fin and an outer fin fixed to a duct located in front of the propeller ship promotes pre-turning upstream of the propeller to improve propeller efficiency.
Since the inner fins and the outer fins are fixed to the duct, even if the inner fins and the outer fins have different installation angles, they can be easily installed through the duct.
The upstream side of the propeller has a complicated flow field due to the hull shape such as bossing. For example, in a plane orthogonal to the propeller rotation axis, the flow from the upper side to the lower side is mainly on the inner peripheral side around the propeller rotation axis, and the flow from the lower side to the upper side is mainly on the outer peripheral side along the circumferential direction. Becomes The present inventors have paid attention to this flow field and found that the installation angles of the inner fins and the outer fins can be optimized.
Specifically, in the case of propeller clockwise rotation, the starboard side (in the case of propeller counterclockwise rotation, the port side) forms an angle of attack with the inflowing water, and When the installation angle is θi and the installation angle of the outer fin with respect to the reference plane is θo, the relationship of θi <θo is established.
On the starboard side in the case of propeller clockwise rotation (port side in the case of propeller left rotation), the flow field on the inner circumference side mainly flows from the upper side to the lower side, and is in substantially the same direction as the propeller rotating from the upper side to the lower side. . Therefore, it is preferable to increase the installation angle θi of the inner fin so as to change the flow upward.
On the other hand, the flow field on the outer peripheral side is mainly a flow from the lower side to the upper side, and is in a direction facing the propeller rotating from the lower side to the upper side. Therefore, it is preferable to increase the installation angle θo of the outer fin so as to promote the flow from the lower side to the upper side. Therefore, the installation angle θo of the outer fin is set to be larger than the installation angle θi of the inner fin (θi <θo).
As described above, the flow field upstream of the propeller is improved on the inner peripheral side and the outer peripheral side, and the propulsion performance can be improved.
When the inner fins and the outer fins have a wing shape, it is preferable to install the wing shape with the ventral side facing upward. This makes it possible to effectively change the flow direction from the lower side to the upper side by utilizing the ventral shape.

  Further, the fin unit device of the present invention is located in front of the propeller ship, and has a duct fixed to the bossing side so as to surround the rotation axis of the propeller, and an outer end portion fixed to the inner peripheral side of the duct. , An inner fin extending substantially inward in the radial direction toward the rotation axis, and an inner end fixed to the outer peripheral side of the duct at a position different from the extending direction of the inner fin, and substantially outward in the radial direction. And an outer fin extending to the.

An inner fin and an outer fin fixed to a duct located in front of the propeller ship promotes pre-turning upstream of the propeller to improve propeller efficiency.
Since the inner fins and the outer fins are fixed to the duct, even if the inner fins and the outer fins have different installation angles, they can be easily installed through the duct.
The upstream side of the propeller has a complicated flow field due to the hull shape such as bossing. For example, in a plane orthogonal to the propeller rotation axis, the flow from the upper side to the lower side is mainly on the inner peripheral side around the propeller rotation axis, and the flow from the lower side to the upper side is mainly on the outer peripheral side along the circumferential direction. Becomes The present inventors have paid attention to this flow field and found that the installation angles of the inner fins and the outer fins can be optimized.
Specifically, the outer fins are provided at positions different from the extending direction of the inner fins. Inner fins and outer fins can be installed at appropriate positions independently on the inner peripheral side and outer peripheral side where the flow fields are different, and the flow field upstream of the propeller is improved on the inner peripheral side and outer peripheral side, and propulsion performance is improved. Can be improved.
It should be noted that the invention may be combined with the above invention regarding the installation angles of the inner fin and the outer fin.

Further, in the fin unit device of the present invention, the inner fin is provided below the duct, and the outer fin is not provided.

The outer peripheral side below the duct is a region where the flow velocity in the direction of the propeller rotation axis is large, and the outer fin may become a resistance. Therefore, the outer fin is not provided below the duct. In such a case, the number of outer fins may be smaller than the number of inner fins.
The lower side of the duct means, for example, a region below a horizontal line passing through the propeller rotation axis when the duct is viewed from the rear of the ship.

Further, in the fin unit device of the present invention, when the propeller rotates clockwise when viewed from the rear of the ship, or on the starboard side when the propeller rotates counterclockwise when viewed from the rear of the ship, the outside The inner end of the fin is fixed to the duct at a position near the inner end and above the corresponding inner fin.

  When the propeller is rotating to the right when viewed from the rear of the ship, or on the starboard side when the propeller is rotating to the left when viewed from the rear of the ship, place the inner end of the outer fin from the corresponding inner fin. Also decided to fix it to the duct at the upper position. This is because when the propeller rotates clockwise, the port on the port side (in the case of propeller left rotation, the starboard side) can avoid a larger flow velocity in the direction of the propeller rotation axis toward the upper region. This is because the effect of field improvement is great.

  Further, the fin unit device of the present invention is located in front of the propeller ship, and has a duct fixed to the bossing side so as to surround the rotation axis of the propeller, and an outer end portion fixed to the inner peripheral side of the duct. , An inner fin extending substantially inward in the radial direction toward the rotation axis, and an inner end portion fixed to the outer peripheral side of the duct while being located in the extending direction of the inner fin, and being substantially outward in the radial direction. With extending outer fins, above the port side when the propeller is rotating to the right when viewed from the rear of the ship, or above the starboard side when the propeller is rotating to the left when viewed from the rear of the ship. The extending direction of the outer fins is higher than the extending direction of the corresponding inner fins.

An inner fin and an outer fin fixed to a duct located in front of the propeller ship promotes pre-turning upstream of the propeller to improve propeller efficiency.
Since the inner fins and the outer fins are fixed to the duct, even if the inner fins and the outer fins have different installation angles, they can be easily installed through the duct.
The upstream side of the propeller has a complicated flow field due to the hull shape such as bossing. For example, in a plane orthogonal to the propeller rotation axis, the flow from the upper side to the lower side is mainly on the inner peripheral side around the propeller rotation axis, and the flow from the lower side to the upper side is mainly on the outer peripheral side along the circumferential direction. Becomes The present inventors have paid attention to this flow field and found that the installation angles of the inner fins and the outer fins can be optimized.
Specifically, in the case of propeller clockwise rotation, above the port side (in the case of propeller counterclockwise rotation, above the starboard side), the extension direction in the radial direction of the outer fin is set to the radial direction of the corresponding inner fin. It was designed to point upwards rather than the extension direction. As a result, the flow can be changed in the direction opposite to the propeller rotating from the lower side to the upper side.
It should be noted that, in the case of propeller clockwise rotation, above port side (in the case of propeller counterclockwise rotation, above starboard side) is, for example, a region above the horizontal line passing through the propeller rotation axis when viewed from the rear of the ship. Means
Further, the invention may be combined with the above invention relating to the installation angles of the inner fins and the outer fins, or the above invention in which the installation positions of the inner fins and the outer fins with respect to the duct are different.

  Further, in the fin unit device of the present invention, the duct has a blade-shaped longitudinal section in which a cord length direction is provided so as to incline toward the rotation axis side from an upstream side to a downstream side. .

  Since the duct has a wing-shaped longitudinal section in which the cord length direction is provided so as to incline from the upstream side to the downstream side toward the propeller rotation axis, the propulsive force can be obtained by the flow flowing into the duct. You can

  Furthermore, the fin unit device of the present invention is characterized in that the cord length below the duct is smaller than the cord length above the duct.

Since the flow field on the inner peripheral side is directed downward below the duct, flow separation easily occurs even in a blade-shaped duct, and propulsive force is difficult to obtain. Therefore, the length of the cord below the duct was made shorter than that above so that it would not become more resistant. The installation angle below the duct may be different from the installation angle above the duct, and the installation angle may be set so that resistance is not further increased.
The lower side of the duct means, for example, a region below a horizontal line passing through the propeller rotation axis when the duct is viewed from the rear of the ship.

  Furthermore, the fin unit device of the present invention is characterized in that a duct defect portion, which is a partial defect of the duct, is provided below the duct.

  Below the duct, a partially defective duct defect portion is provided to form a region where the duct is not provided. Thereby, the flow separation and the resistance of the duct in the region where the flow velocity in the propeller rotation axis direction is high can be reduced.

  Further, in the fin unit device of the present invention, the center position of the duct when viewed from the rear of the hull is different from the rotation axis.

The upstream side of the propeller has a complicated flow field due to the hull shape such as bossing. For this reason, the duct has a region where thrust is generated as described above, while there is a region where the duct itself becomes a resistance. Therefore, the performance of the duct can be effectively exhibited by installing the center position of the duct at a position different from the propeller rotation axis.
For example, at a position where thrust can be generated, such as above the duct, position the duct at a position where thrust can be effectively generated against the flow, and at a position where it is difficult to generate thrust, such as below the duct, streamline as much as possible. Position the ducts along to reduce resistance. In this case, the cross-sectional shape of the duct is not limited to the circular shape, but may be an elliptical shape, an oval shape, or a shape in which a part is cut away. The center position in a shape that is not circular means the centroid.
Further, when the flow field on the upstream side of the propeller changes due to the influence of the rotation of the propeller, the center position of the duct is set accordingly. For example, the center position of the duct may be set so as to be shifted from the vertical line passing through the propeller rotation axis in the propeller rotation direction.

  Further, the watercraft of the present invention is a propeller that rotates around a rotation axis, a bossing that rotatably supports the propeller, a boshing provided in front of the propeller ship, and one of the above-mentioned boshings provided. And a fin unit device.

  Since the inner fins and the outer fins are properly installed according to the flow field on the upstream side of the propeller, the flow field on the upstream side of the propeller can be improved to improve the propulsion performance of the ship.

It is the side view which showed the stern part of the ship which concerns on 1st Embodiment of this invention. It is a front view when the fin unit device concerning a 1st embodiment of the present invention is seen from the back of a ship. It is the side view which showed the inner fin and the outer fin which looked at the fin unit apparatus of FIG. 2 from the port side. It is the side view which showed the inner fin and the outer fin which looked at the fin unit apparatus of FIG. 2 from the starboard side. It is the figure which showed the flow field of the propeller upstream from the back of a ship. It is a front view at the time of seeing the fin unit device concerning a 2nd embodiment of the present invention from the back of a ship. It is a front view at the time of seeing the fin unit device concerning a 3rd embodiment of the present invention from the back of a ship. It is a longitudinal section showing the duct concerning a 4th embodiment. It is a longitudinal section showing a duct concerning a 5th embodiment. It is a front view at the time of seeing the duct concerning a 6th embodiment from the back of a ship. It is a front view at the time of seeing the duct concerning a 7th embodiment from the back of a ship. It is a front view of the duct which showed the modification of FIG. It is a front view of the duct which showed the other modification of FIG.

Embodiments according to the present invention will be described below with reference to the drawings.
[First Embodiment]
FIG. 1 shows a stern portion of a ship 1 according to a first embodiment of the present invention. A stern portion is provided with a bossing 11 and a stern overhang portion 12. The boshing 11 is located on the upstream side of the propeller and rotatably supports the propeller 10 so that the propeller 10 for propulsion can rotate about the rotation axis L1. The stern overhang portion 12 is provided above the propeller 10.

  A fin unit device 20 is attached to the bossing 11. The fin unit device 20 improves the propeller efficiency by generating a swirling flow in a direction opposite to the rotation direction of the propeller 10 when moving forward.

  FIG. 2 shows a front view of the fin unit device 20 as viewed from the rear. As indicated by the coordinate axes in the lower right of FIG. 2, the traveling direction of the ship is the x axis, the horizontal direction orthogonal to the x axis is the y axis, and the vertical direction orthogonal to the x axis is the z axis (hereinafter the same).

  The fin unit device 20 includes a duct 22, an inner fin 24 located on the inner peripheral side of the duct 22, and an outer fin 25 located on the outer peripheral side of the duct 22.

  The duct 22 has a cylindrical shape, and the central axis of the duct 22 coincides with the rotation axis L1 of the propeller 10. The radius of the duct 22 is 0.3R or more and 0.9R or less, where R is the radius of the propeller 10.

  The inner fin 24 has an inner end fixed to the boshing 11 and an outer end fixed to the inner peripheral surface of the duct 22. The inner fins 24 extend in the radial direction around the rotation axis L1. As shown in FIGS. 3 and 4, the inner fins 24 have a wing-shaped cross section, and are arranged so that the tip of the wing faces the front side of the vessel and the rear end of the wing faces the rear side of the vessel.

  As shown in FIG. 2, the outer fin 25 has an inner end fixed to the outer peripheral surface of the duct 22 and an outer end free. The outer end of the outer fin 25 is arranged at a position equivalent to the outer diameter D1 of the propeller 10. The outer fins 25 extend in the radial direction about the rotation axis L1 so as to match the extending direction of the corresponding inner fins 24. As shown in FIGS. 3 and 4, the outer fin 25 has a wing-shaped cross section, and is arranged so that the tip of the wing faces the front side of the vessel and the rear end of the wing faces the rear side of the vessel.

Six pairs of inner fins 24 and outer fins 25 extending in the same radial direction are provided in this embodiment. Specifically, three pairs of lower fins 24a, 25a, middle fins 24b, 25b and upper fins 24c, 25c are provided on the port side, and lower fins 24d, 25d and middle fins are provided on the starboard side. Three pairs of 24e, 25e and upper fins 24f, 25f are provided. The fins 24, 25 of each pair are provided symmetrically with respect to the vertical line V passing through the rotation axis L1, but their positions can be changed appropriately.
The fins 24b, 25b, 24e, 25e in the middle stage extend in the horizontal line H direction. The lower fins 24a, 25a, 24d, 25d and the upper fins 24c, 25c, 24f, 25f are distributed to the object with respect to the extending direction (horizontal line H direction) of the middle fins 24b, 25b, 24e, 25e. It is arranged. However, the present invention is not limited to these fin arrangements.

  As described above, the inner fins 24 and the outer fins 25 are fixed to the duct 22, respectively. Therefore, even if the inner fins 24 and the outer fins 25 have different installation angles as described later, they can be easily inserted through the duct 22. It can be installed in.

  The propeller 10 rotates clockwise as seen from the rear of the ship, as indicated by arrow A1 in FIG.

FIG. 3 shows the inner fins 24 and the outer fins 25 as viewed from the port side. In the figure, the water flow flows from right to left as indicated by arrow A2. The inner fins 24 and the outer fins 25 are arranged with the ventral side of the wing shape facing down and the back side facing up. The inner fins 24 are arranged at an installation angle θi with respect to the reference plane P1 including the rotation axis L1 (see FIG. 2). The outer fins 25 are arranged at an installation angle θo with respect to the reference plane P2 including the rotation axis L1 (see FIG. 2). Then, on the port side, the relationship between these installation angles θi and θo is expressed by the following equation.
θi> θo (1)

FIG. 4 shows the inner fins 24 and the outer fins 25 as viewed from the starboard side. In the figure, the water flow flows from right to left as indicated by arrow A3. The inner fins 24 and the outer fins 25 are arranged so that the ventral side of the wing shape is up and the back side is down. The inner fins 24 are arranged at an installation angle θi with respect to the reference plane P1 including the rotation axis L1 (see FIG. 2). The outer fins 25 are arranged at an installation angle θo with respect to the reference plane P2 including the rotation axis L1 (see FIG. 2). Then, on the starboard side, the relationship between these installation angles θi and θo is expressed by the following equation.
θi <θo (2)

The operation and effect of this embodiment having the above configuration will be described below.
The upstream side of the propeller 10 forms a complicated flow field as shown in FIG. 5 depending on the shape of the bossing 11 and the shapes of the hulls on the upstream side and the surroundings reaching the bossing 11. This figure shows the flow field on the upstream side of the propeller 10 as seen from the rear of the ship, as in FIG. In the figure, a horizontal line H and a vertical line V passing through the rotation axis L1 are shown. A solid line drawn like a contour line shows a constant flow rate line in the direction of the rotation axis L1 (direction perpendicular to the plane of the drawing). The flow rate is smaller on the inner peripheral side closer to the rotation axis L1 and higher on the outer peripheral side. The plurality of arrows indicate the flow direction of the water flow in the plane orthogonal to the rotation axis L1 (the yz plane).

  As can be seen from the figure, the flow from the upper side to the lower side is mainly on the inner peripheral side around the rotation axis L1, and the flow from the lower side to the upper side is mainly on the outer peripheral side along the circumferential direction. The region indicated by reference numeral S1 is located below the rotation axis L1 and on the outer peripheral side, and is a region where the flow velocity in the rotation axis L1 direction is large due to the influence of the flow outside the hull.

As shown in the above equation (1), in the case of propeller clockwise rotation, the relationship between the installation angle θi of the inner fins 24 and the installation angle θo of the outer fins 25 on the port side was set to θi> θo. The reason for this is as follows.
On the port side in the case of right rotation of the propeller, the flow field on the inner peripheral side is, as shown in FIG. 5, mainly the flow from the upper side to the lower side, and the direction opposite to the propeller 10 rotating from the lower side to the upper side. . Therefore, the installation angle θi of the inner fin 24 is increased so as to promote the flow from the upper side to the lower side. The installation angle θi is set to have an angle of attack along the inflowing flow. In this case, the angle of attack is set to, for example, 0 ° or more and 20 ° C or less, preferably 0 ° or more and 15 ° or less.

On the other hand, the flow field on the outer peripheral side is mainly a flow from the lower side to the upper side, and is in substantially the same direction as the propeller 10 rotating from the lower side to the upper side. Therefore, it is preferable that the outer fin 25 has an installation angle that changes the flow downward. However, since the flow velocity on the outer peripheral side in the direction of the rotation axis L1 of the propeller 10 is higher than that on the inner peripheral side, if the installation angle θo of the outer fin 25 is set so as to obtain a large angle of attack, the outer fin 25 becomes a resistance against the flow. Therefore, it is not preferable. Therefore, as shown in the equation (1), the installation angle θo of the outer fin 25 is set smaller than the installation angle θi of the inner fin 24.
As described above, the flow field on the upstream side of the propeller 10 is improved on the inner peripheral side and the outer peripheral side, and the propulsive performance of the ship 1 can be improved.

  With respect to the inner fins 24 and the outer fins 25, the wing-shaped ventral side is set to face downward. This makes it possible to effectively change the flow direction from the upper side to the lower side by utilizing the ventral shape, and further improve the flow field.

Further, as shown in the above equation (2), when the propeller 10 is rotated to the right, the relationship between the installation angle θi of the inner fin 24 and the installation angle θo of the outer fin 25 is θi <θo on the starboard side. did. The reason for this is as follows.
As shown in FIG. 5, the flow field on the inner peripheral side is mainly the flow from the upper side to the lower side, and is in substantially the same direction as the propeller 10 rotating from the upper side to the lower side. Therefore, the inner fin 24 has a large installation angle θi so as to change the flow upward.
On the other hand, the flow field on the outer peripheral side is mainly a flow from the lower side to the upper side, and is in a direction facing the propeller 10 rotating from the lower side to the upper side. Therefore, the installation angle θo of the outer fin 25 is increased so as to promote the flow from the lower side to the upper side. The installation angle θo is set to have an angle of attack along the inflowing flow, and in this case, the angle of attack is set to, for example, 0 ° or more and 20 ° C or less, preferably 0 ° or more and 15 ° or less.
From the above, as shown in the equation (2), the installation angle θo of the outer fin 25 is set to be larger than the installation angle θi of the inner fin 24.

  With respect to the inner fins 24 and the outer fins 25, the wing-shaped ventral side is set to face upward. Thereby, the flow direction can be effectively changed from the lower side to the upper side by utilizing the ventral shape, and the flow field can be further improved.

  The present embodiment has been described on the premise that the propeller rotates clockwise, but the present embodiment can be applied to the case where the propeller rotates counterclockwise. Specifically, when the propeller is turned clockwise, the port side corresponds to the starboard side when the propeller is turned counterclockwise, and when the propeller is turned clockwise, what is used as the starboard side corresponds to the propeller counterclockwise port side. . This also applies to each of the following embodiments.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
The present embodiment is different from the first embodiment in the arrangement of the inner fins 24 and the outer fins 25, and is otherwise the same. Therefore, only the differences will be described below, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

  As shown in FIG. 6, there is a pair in which the corresponding outer fin 25 is not provided at a position corresponding to the extending direction of the inner fin 24.

  Specifically, there is no corresponding outer fin 25 in the extending direction of the lower inner fin 24a on the port side and the lower inner fin 24d on the starboard side. Thus, the outer fin 25 is not provided at the position on the lower side and the outer peripheral side where the flow velocity in the direction of the rotation axis L1 is large, thereby avoiding resistance. As described above, it is preferable that the outer fins 25 are not provided below the duct 22, that is, in a region below the horizontal line H passing through the rotation axis L1.

  In addition, a corresponding outer fin 25b is provided at a position B1 which is displaced upward from the extending direction of the inner fin 24b on the port side middle stage. That is, the inner end of the outer fin 25b is fixed to the duct 22 above the position where the outer end of the corresponding inner fin 24b is fixed to the duct 22. This is because the flow velocity in the direction of the rotation axis L1 that is larger in the upper region can be avoided, and the effect of improving the flow field by providing the outer fins 25b in this region is large.

  On the other hand, corresponding outer fins 25c, 25f are provided in the extending direction of the upper inner fins 24c on the port side and the upper inner fins 24f on the starboard side. This arrangement is the same as in the first embodiment.

The installation angles θi and θo of the fins 24 and 25 are determined according to the flow field as in the first embodiment.
As described above, in the present embodiment, the number of the outer fins 25 is smaller than the number of the inner fins 24, and the respective numbers are different.

According to this embodiment, the following operational effects are exhibited.
By providing the outer fins 25 at positions different from the extending direction of the corresponding inner fins 24, the inner fins 24 and the outer fins 25 are independently positioned at proper positions on the inner peripheral side and the outer peripheral side where the flow fields are different. Can be installed in As a result, the flow field upstream of the propeller is improved on the inner peripheral side and the outer peripheral side, and the propulsion performance can be improved.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG.
The present embodiment is different from each of the above-described embodiments in the arrangement of the inner fins 24 and the outer fins 25, and is otherwise the same. Therefore, only the differences will be described below, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

  As shown in FIG. 7, the extending direction in the radial direction of the port outer middle fin 25b and the port upper outer fin 25c is larger than the corresponding radial direction of the corresponding inner fins 24b, 24c. Facing upwards.

The outer fins 25b in the middle of the port side are fixed to the duct 22 at a position B1 above the extending direction of the corresponding inner fins 24b, and above the horizontal line H that is the extending direction of the corresponding inner fins 24b. It is arranged to face.
The outer fins 25c on the upper end of the port side are fixed at the same circumferential position as the position where the corresponding inner fins 24c are fixed to the duct 22, while the fixed position with respect to the duct 22 serves as a boundary. On the other hand, it is arranged in a state of being bent upward.

  The starboard side outer fins 25e, 25f are provided in the same extending direction as the corresponding inner fins 243, 24f, as in the first embodiment.

With such a configuration, the following operational effects are exhibited.
Since the extending directions of the outer fins 25b and 25c are set to be higher than the extending directions of the corresponding inner fins 24b and 24c, the flow in the direction facing the propeller 10 rotating from the lower side to the upper side on the port side. Can be changed. Accordingly, the propeller efficiency can be improved by further improving the flow field above the port side.
In addition, the upper side on the port side means an area above a horizontal line H passing through the rotation axis L1.
Further, the invention of this embodiment may be combined with the invention of each of the above-described embodiments.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIG.
The present embodiment relates to the structure of the duct 22 shown in each of the above embodiments, and is otherwise the same. Therefore, only the differences will be described below, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

FIG. 8 shows a vertical sectional view of the duct 22. In the figure, the water flow flows from right to left as indicated by arrow A4.
The vertical cross section of the duct 22 has a wing shape. The cord length direction is provided so as to incline toward the rotation axis L1 side from the upstream side to the downstream side. That is, the downstream opening is smaller than the upstream opening of the duct 22. In addition, the ventral side of the wing shape is provided so as to face the inner peripheral side (the rotation axis L1 side).

According to this embodiment, the following operational effects are exhibited.
Since the duct 22 has a wing-shaped longitudinal section in which the cord length direction is provided so as to incline toward the rotation axis L1 side from the upstream side to the downstream side, the propulsive force is generated by the flow flowing into the duct 22. Obtainable. That is, above the duct 22, the water flow that has flowed into the inner peripheral side of the duct 22 generates lift F1 on the ventral side of the blade shape. The component of the lift F1 on the rotation axis L1 becomes the propulsion force.

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described with reference to FIG.
The present embodiment is different from the duct of the fourth embodiment in shape, but is otherwise the same. Therefore, only the differences will be described below, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

  As shown in FIG. 9, the cord length below the duct 22 is smaller than the cord length above the duct 22. That is, the downstream opening position of the duct 22 is aligned above and below the duct 22 in the rotation axis L1 direction, but the upstream opening position of the duct 22 is below the duct 22 above the water flow. It is located on the downstream side of.

According to this embodiment, the following operational effects are exhibited.
As shown in FIG. 5, below the duct 22, the flow field on the inner peripheral side is directed downward, so that flow separation may occur even in the wing-shaped duct 22 and a propulsive force can be obtained. It is hard to be caught. Therefore, the cord length below the duct 22 is made shorter than the cord length above so as not to become more resistant.
It should be noted that the installation angle below the duct 22 may be different from that above the duct 22 so as to set an installation angle that does not cause more resistance.

[Sixth Embodiment]
Next, a sixth embodiment of the invention will be described with reference to FIG.
The present embodiment is different in shape from the ducts of the fourth and fifth embodiments, but is otherwise the same. Therefore, only the differences will be described below, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

  As shown in FIG. 10, below the duct 22, a duct defective portion 22a in which the duct 22 is partially broken is provided. That is, the duct 22 does not exist between the lower inner fins 24a and 24d. Therefore, the cross-sectional shape of the duct 22 is a C shape having an opening downward.

According to this embodiment, the following operational effects are exhibited.
Below the duct 22, a partially missing duct missing portion 22a is provided to form a region where the duct 22 is not provided. Thereby, the flow separation and the resistance of the duct 22 in the region where the flow velocity in the direction of the rotation axis L1 is high can be reduced.
The present embodiment can be combined with each of the above-described embodiments.

[Seventh Embodiment]
Next, a seventh embodiment of the present invention will be described with reference to FIGS. 11 to 13.
The present embodiment is different from the ducts of the fourth to sixth embodiments in shape, but is otherwise the same. Therefore, only the differences will be described below, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

  FIG. 11 is a diagram showing the duct 22 superimposed on the flow field shown in FIG. As shown in the figure, the duct center C1 is located at a position different from the rotation axis L1 and is provided above the rotation axis L1. The cross-sectional shape of the duct 22 is an elliptical shape having a long axis coinciding with the vertical line V. The duct center C1 is an oval centroid.

The upper half portion of the duct 22 is installed in a region that flows from above toward the duct center C1. Thereby, the thrust can be more effectively generated in the duct 22.
In the lower half portion of the duct 22, the major axis of the ellipse is directed to the vertical line V direction, and the left and right wall portions in the figure are extended in the vertical direction so that the flow can be made to follow the vertical flow to reduce the resistance. There is. Further, by directing the minor axis of the ellipse in the direction of the horizontal line H, the area of the lower end portion of the duct 22 is shortened and the resistance is reduced.

FIG. 12 shows a modification of FIG. 11. As shown in the figure, the duct center C1 is provided below the rotation axis L1. The elliptical shape of the cross section of the duct 22 is provided with a short axis corresponding to the vertical line V and a long axis along the horizontal line H direction.
The upper half portion of the duct 22 is installed in a region that flows from above toward the duct center C1. Thereby, the thrust can be more effectively generated in the duct 22.
The lower half portion of the duct 22 is provided so that the water flow is deflected in the left-right direction (horizontal direction) from the downward flow and substantially coincides with the upward flow. As a result, the resistance of the duct 22 can be reduced.

  Although the duct 22 has an elliptical cross-sectional shape in FIGS. 11 and 12, the shape is not limited to this, and the duct 22 may have a shape in which a plurality of curvatures are combined so that the duct 22 has an appropriate position according to the flow field. Is also good.

FIG. 13 shows another modification. As shown in the figure, the duct center C1 is located above and to the right of the rotation axis L1. This corresponds to the case where the flow field on the upstream side of the propeller 10 is deviated by a predetermined angle in the right direction indicated by the arrow A5 about the rotation axis L1 due to the influence of the rotation of the propeller 10. That is, the horizontal line of the flow field is displaced to the position indicated by the reference symbol H'and the vertical line is displaced to the position indicated by the reference symbol V '. This allows the duct 22 to be installed at an appropriate position according to the flow field.
The present embodiment can be combined with each of the above-described embodiments.

1 Ship 10 Propeller 11 Bossing 12 Stern Overhang 20 Fin Unit Device 22 Duct 24 Inner Fin 25 Outer Fin L1 Rotation Axis D1 Propeller Outer Diameter A1 Propeller Rotation Direction A2, A3, A4 Water Flow Direction H Horizontal Line V Vertical Line

Claims (10)

A duct located in front of the propeller ship and fixed to the bossing side so as to surround the rotation axis of the propeller,
An inner fin whose outer end is fixed to the inner peripheral side of the duct and extends substantially inward in the radial direction toward the rotation axis,
Outer fins that are located in the extending direction of the inner fins, have inner ends fixed to the outer peripheral side of the duct, and extend substantially outward in the radial direction,
Equipped with
At least a pair of the inner fin and the outer fin,
On the port side when the propeller rotates right when viewed from the rear of the ship, or on the starboard side when the propeller rotates left when viewed from the rear of the ship,
When an angle of attack is formed with respect to the inflowing water, the installation angle of the inner fin with respect to the reference plane including the rotation axis is θi, and the installation angle of the outer fin with respect to the reference plane is θo,
θi> θo
A fin unit device characterized in that A duct located in front of the propeller ship and fixed to the bossing side so as to surround the rotation axis of the propeller,
An inner fin whose outer end is fixed to the inner peripheral side of the duct and extends substantially inward in the radial direction toward the rotation axis,
Outer fins that are located in the extending direction of the inner fins, have inner ends fixed to the outer peripheral side of the duct, and extend substantially outward in the radial direction,
Equipped with
At least a pair of the inner fin and the outer fin,
On the starboard side when the propeller rotates right when viewed from the rear of the ship, or on the port side when the propeller rotates left when viewed from the rear of the ship,
When an angle of attack is formed with respect to the inflowing water, the installation angle of the inner fin with respect to the reference plane including the rotation axis is θi, and the installation angle of the outer fin with respect to the reference plane is θo,
θi <θo
A fin unit device characterized in that A duct located in front of the propeller ship and fixed to the bossing side so as to surround the rotation axis of the propeller,
An inner fin whose outer end is fixed to the inner peripheral side of the duct and extends substantially inward in the radial direction toward the rotation axis,
An outer fin whose inner end is fixed to the outer peripheral side of the duct at a position different from the extending direction of the inner fin, and which extends substantially outward in the radial direction;
Equipped with
A fin unit device characterized in that the inner fin is provided below the duct, and the outer fin is not provided . On the port side when the propeller rotates right when viewed from the rear of the ship, or on the starboard side when the propeller rotates left when viewed from the rear of the ship,
The inner end portion of the outer fin, according to claim 3, characterized in that it is fixed to the duct at a position above said inner fins which corresponds close to the inner lateral ends Fin unit device. A duct located in front of the propeller ship and fixed to the bossing side so as to surround the rotation axis of the propeller,
An inner fin whose outer end is fixed to the inner peripheral side of the duct and extends substantially inward in the radial direction toward the rotation axis,
Outer fins that are located in the extending direction of the inner fins, have inner ends fixed to the outer peripheral side of the duct, and extend substantially outward in the radial direction,
Equipped with
Above the port side when the propeller is rotating to the right when viewed from the rear of the ship, or above the starboard side when the propeller is rotating to the left when viewed from the rear of the ship,
The fin unit device, wherein the extending direction of the outer fins is higher than the extending direction of the corresponding inner fins. The duct according to any one of claims 1 to 5, characterized in that it comprises a longitudinal section of the wing shape code length direction is provided to the upstream side toward the downstream side inclined to the axis of rotation side Fin unit device. The fin unit device according to claim 6 , wherein the cord length below the duct is smaller than the cord length above the duct. The fin unit device according to claim 6 or 7 , wherein a duct defective portion, which is a partial defect of the duct, is provided below the duct. Center position when viewed the duct from the hull behind the fin unit according to any one of claims 6 to 8, characterized in that different from the rotational axis. A propeller that rotates around the axis of rotation,
While rotatably supporting the propeller, bossing provided in front of the propeller ship,
The fin unit device according to any one of claims 1 to 9 , which is provided on the bossing,
A ship characterized by being equipped with.

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