A pre-rotation combined guide vane and ship

Abstract

The application provides a combined guide vane and a ship, which achieves the basic requirement of improving the flow field around the stern and propeller and improving the propeller efficiency, reduces the stress on the structure by arranging the guide vanes in the axial direction, increases the energy saving effect, and avoids the negative influence of the axial misalignment arrangement on the propeller pulsating pressure by aligning the end. In addition, by limiting the circumferential length of the guide vane, the resistance generated by the device is small, that is, the resistance and structural performance of the energy saving device are improved; through the combination of various schemes of the guide vane, the guide vane, the connecting piece and the flow guide fin, and the establishment of the design method matched with each combination of the application, the optimal energy saving effect can be achieved for different ship types and navigation conditions, the effective complementation among multiple structures is realized, and the universality is strong.

Description

Technical Field

[0001] This invention relates to the field of ship propulsion components technology, and in particular to a pre-rotation guide wheel and a ship. Background Technology

[0002] Propeller inlet energy-saving devices are steel structures installed at the stern of a ship, in front of the propeller. They come in various forms, including pre-spin guide vanes and compensating ducts. Currently, the most common form on the market is a combination of both: a pre-spin guide wheel, which consists of an airfoil-like pre-spin stator and an asymmetric arc-shaped duct. By rectifying the flow field in front of the propeller and applying appropriate pre-spinning, it improves propeller propulsion efficiency. Practical application shows that installing such devices can typically result in energy savings of approximately 3-8% for ships.

[0003] In the patent application number 202411651042.1 submitted by the applicant, entitled "A flow guiding device for a ship propeller and a ship", although a basic structure of a flow guiding device was disclosed, it failed to provide clear limitations on the specific combination form and related structural parameters of key components such as guide vanes and guide wheels. As a result, the device is difficult to achieve the optimal flow field control effect in actual application, thus limiting the full realization of its flow guiding efficiency and energy-saving potential. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the present invention provides a pre-swirl combined guide wheel, which divides the ship into left and right sides with the longitudinal section where the propeller shaft is located. Multiple guide vanes are asymmetrically distributed on the left and right sides. The roots of the multiple guide vanes are fixedly connected to the stern of the hull around the propeller. The number of guide vanes on the left side is 3-4 and the number of guide vanes on the right side is 1-2. The guide vanes are used to support the guide wheel and generate a pre-swirl flow that is beneficial to the propeller propulsion efficiency. The arc-shaped guide wheel is connected to two or more guide vanes around the circumference, and some guide vanes have end plates at the ends away from the propeller shaft.

[0005] With the longitudinal section where the propeller shaft is located as the 0° reference plane, the left / right guide vanes are named the first guide vane, second guide vane, third guide vane, etc., according to the angle between them and the longitudinal section from large to small; among them, the two left guide vanes and one right guide vane closest to the longitudinal section are fixedly connected to the guide wheel.

[0006] Optionally, the guide vanes include a left first guide vane, a left second guide vane, a left third guide vane, a right first guide vane, and a right second guide vane; the propeller radius is defined as R.

[0007] Optionally, the length of the left guide vane is 0.6-1.0R, the length of the right second guide vane is 0.2-1.0R, and the length of the right first guide vane is 0.2-0.6R, which is less than the length of the left guide vane.

[0008] Optionally, the guide wheel includes a first guide wheel, a second guide wheel, and a third guide wheel, wherein the ends of the left first guide vane and the left second guide vane are provided with end plates, while the right second guide vane is not provided with end plates;

[0009] The first guide wheel connects the middle of the first guide vane on the left and the middle of the second guide vane on the left. The second guide wheel connects the middle of the third guide vane on the left and the second guide vane on the right. The third guide wheel connects the ends of the third guide vane on the left and the second guide vane on the right. The second guide wheel and the first guide wheel have the same radius and are integrated to form an integrated guide wheel. The vertex radius of the integrated guide wheel is 0.4-0.6R. The third guide wheel is located on the outer side of the integrated guide wheel away from the propeller shaft. The vertex radius of the third guide wheel is 0.75-0.95R. The distance between the third guide wheel and the integrated guide wheel at the mid-longitudinal section is 0.3-0.5R.

[0010] Optionally, the guide wheel includes a first guide wheel and a third guide wheel. The first guide wheel connects the middle part of the left first guide vane and the middle part of the left second guide vane, and the third guide wheel connects the middle part of the left third guide vane and the end of the right second guide vane. The first guide wheel and the third guide wheel have the same radius and are integrated, with their vertex radius ranging from 0.45 to 0.65R. The left guide vane and the guide wheel are cross-connected, and the right second guide vane is located on the inner side of the third guide wheel near the propeller shaft. The ends of the left first guide vane, the left second guide vane, and the left third guide vane are provided with end plates, while the ends of the right first guide vane and the right second guide vane are not provided with end plates.

[0011] Optionally, the guide wheel includes a first guide wheel and a third guide wheel. The first guide wheel connects the end of the left second guide vane and the end of the left third guide vane, and the third guide wheel connects the end of the left third guide vane and the end of the right second guide vane. The first guide wheel and the third guide wheel have the same radius and are integrated into one piece, with a vertex radius ranging from 0.75 to 0.95R. The left second guide vane, the left third guide vane, and the right second guide vane are all located inside the guide wheel. The end of the left first guide vane is provided with an end plate, while the ends of the right first guide vane, the right second guide vane, the left second guide vane, and the left third guide vane are not provided with end plates.

[0012] Optionally, the radial cross-sectional profile of the guide wheel includes an upper surface, front and rear circular arcs, and a lower surface. The upper and lower surfaces are straight lines or convex arcs, and both the upper and lower surfaces are tangent to the front and rear circular arcs.

[0013] The line connecting the centers of the front and rear arcs is the chord of the guide wheel section. The angle between the chord and the horizontal line in the plane containing the guide wheel section is the angle of attack Sα of the guide wheel section. The length between the two intersection points formed by the extended chord and the front and rear arcs is the chord length c1. The radii of the front and rear arcs are Sr1 and Sr2, respectively, and Sr1≥Sr2 to achieve effective flow guidance of the guide wheel. Sb≥2Sr1 to ensure a smooth transition. The maximum thickness of the guide wheel section is Sb. The intersection of the measurement line containing the maximum thickness with the upper and lower surfaces is the upper measurement point and the lower measurement point. Along the chord direction, the distances between the upper measurement point and the lower measurement point and the front end point of the front arc are Sc1 and Sc2, respectively. The chord length c1 of the guide wheel section is ≤0.6R.

[0014] Optionally, the guide wheel section farther from the center longitudinal section has a smaller maximum thickness Sb and angle of attack Sα compared to the guide wheel section closer to the center longitudinal section.

[0015] Optionally, the projections of the left and right sides of the guide wheel on the mid-longitudinal section do not coincide; the coordinate difference between the left and right ends of the guide wheel along the ship's length is the stretching distance p, and the stretching distance p is 0-0.15R.

[0016] Optionally, the radius of the guide wheel gradually decreases from front to back; the front radius rf of the guide wheel is 1-1.2 times the rear radius rb of the guide wheel.

[0017] Optionally, the cross-sectional profile of the guide vane includes a left surface, front and rear circular arcs, and a right surface, with both the left and right surfaces being tangent to the front and rear circular arcs. The right surface is a convex arc, and the left surface is a straight line or a concave-convex arc, with both surfaces being tangent to the front and rear circular arcs. The line connecting the centers of the front and rear circular arcs is the chord of the guide vane cross-section, and the angle between the chord and the mid-longitudinal section is the angle of attack Fα of the guide vane cross-section. The length between the two intersection points formed by extending the chord to the front and rear circular arcs is the chord length c2. The radii of the front and rear circular arcs are Fr1 and Fr2, respectively, with Fr1 > Fr2, to prevent excessive flow separation from the guide vane. The maximum thickness of the guide vane cross-section is Fb, and the intersection of the measurement line containing the maximum thickness with the left and right surfaces is the left measurement point and the right measurement point. Along the chord direction, the distances between the left and right measurement points and the front end point of the front circular arc are Fc1 and Fc2, respectively, with Fb ≥ 2Fr1. The chord length c2 of the guide vane cross-section is ≤ 0.6R.

[0018] Optionally, along the radial direction of the propeller shaft, the guide vane gradually contracts from the root to the tip, and the chord length of the guide vane tip is 0.5-1 times the chord length of the guide vane root, forming a guide vane whole that continuously contracts from the root to the tip.

[0019] Optionally, Dij represents the distance along the ship's length between the leading ends of the j-th leading guide vane and the (j+1)-th leading guide vane in the i-th guide vane arrangement.

[0020] In the first guide vane arrangement, the third guide vane on the left, the first guide vane on the right, and the second guide vane on the right are all the first forward guide vanes, the second guide vane on the left is the second forward guide vane, and the first guide vane on the left is the third forward guide vane; D11: 0-0.03R, D12: 0-0.02R, and D11>D12;

[0021] In the second guide vane arrangement, the second guide vane on the left, the third guide vane on the left, the first guide vane on the right, and the second guide vane on the right are all the first forward guide vanes, and the first guide vane on the left is the second forward guide vane; D21: 0-0.02R;

[0022] In the third guide vane arrangement, the second guide vane on the left and the second guide vane on the right are simultaneously the first forward guide vanes, and the first guide vane on the left, the third guide vane on the left, and the first guide vane on the right are simultaneously the second forward guide vanes; D31: 0-0.04R;

[0023] In the fourth guide vane arrangement, the second guide vane on the left and the second guide vane on the right are both the first forward guide vanes, the third guide vane on the left and the first guide vane on the right are both the second forward guide vanes, and the first guide vane on the left is the third forward guide vane; D41: 0-0.05R, D42: 0-0.02R, and D41> D42;

[0024] In the fifth guide vane arrangement, the first and second guide vanes on the right are simultaneously the first forward guide vanes, the third guide vane on the left is the second forward guide vane, the second guide vane on the left is the third forward guide vane, and the first guide vane on the left is the fourth forward guide vane; D51: 0-0.01R; D53: 0-0.03R; and D51 gradually increases to D53.

[0025] Optionally, the roots of multiple guide vanes are distributed back and forth along the axial direction, and the ends of multiple guide vanes are located at the same position in the axial direction, with a linear transition between the roots and the ends.

[0026] Optionally, the cross-sectional shape of the end plate includes an ellipse or an airfoil shape with a pointed front and rounded rear; the structural form of the end plate includes a planar body and a contracted body.

[0027] The upper surface of the planar body is three-dimensionally stretched into an upper curved surface, transforming the planar body into a contracted body. The cross-sectional shape of the contracted body remains airfoil-shaped, and the upper curved surface of the contracted body is streamlined with a lower front and a higher back. The top edge of the upper curved surface tapers into a cusp or an airfoil-shaped opening.

[0028] Optionally, the y-direction is positive from the propeller shaft center to the left side of the hull; the z-direction is positive from the propeller shaft center to the deck; the guide wheel of the pre-spinning assembly forms a pitch angle β relative to the yoz plane, and the pitch angle β ranges from -5 to 15°.

[0029] Optionally, the pre-rotation guide wheel is connected and fixed to the stern of the hull via a connector, and multiple guide fins are provided at the stern of the hull, with the multiple guide fins parallel to each other; the guide fins are arranged only on the right side, and one of the guide fins is integrated with the connector.

[0030] The present invention also provides a vessel equipped with the aforementioned diversion and pre-spinning combined guide wheel.

[0031] As described above, this invention provides a combined guide wheel and vessel for diversion and pre-spinning. This combined guide wheel achieves the basic requirements of improving the flow field around the stern and propeller, and increasing propeller efficiency. Furthermore, by arranging the guide vanes axially, it reduces the stress on the structure, increasing energy-saving effects. Simultaneously, end alignment avoids the negative impact of axial misalignment on propeller pulsating pressure. In addition, by limiting the circumference length of the guide wheel, the resistance generated by the device is reduced, thus improving the resistance and structural performance of the energy-saving device. Through various combinations of guide wheels, guide vanes, connectors, and guide fins, and by establishing a design method that matches each combination of this invention, superior energy-saving effects can be achieved for different ship types and navigation conditions. It realizes effective complementarity among multiple structures and has strong versatility. Attached Figure Description

[0032] Figure 1 The diagram shown is a three-dimensional structural schematic of the pre-rotation combined guide wheel of the present invention.

[0033] Figure 2 The diagram shows the orientation definition of the pre-rotation combined guide wheel of the present invention.

[0034] Figure 3a The diagram shows the flow field without the pre-swirl guide wheel.

[0035] Figure 3b This is a schematic diagram of the flow field with the pre-swirl guide wheel set.

[0036] Figure 4 The diagram shown is a schematic diagram of the first embodiment of the pre-rotation combined guide wheel of the present invention.

[0037] Figure 5 The diagram shows the position of the guide wheel center and the propeller shaft center, as well as the radius of the vertex, in this invention.

[0038] Figure 6 The diagram shown is a schematic diagram of a second embodiment of the pre-rotation combined guide wheel of the present invention.

[0039] Figure 7 The diagram shown is a third embodiment of the pre-rotation combined guide wheel of the present invention.

[0040] Figure 8 The diagram shown is a schematic diagram of the cross-section and parameters of the guide wheel in this invention.

[0041] Figure 9 The diagram shows the variation of the guide wheel cross-section in this invention.

[0042] Figure 10 The diagram shows the sweeping of the guide wheel along the spiral line and the shrinkage of the guide wheel radius in this invention.

[0043] Figure 11 The diagram shows the cross-section and parameters of the guide vane in this invention.

[0044] Figure 12 The diagram shows the variation of the guide vane cross section in this invention.

[0045] Figure 13 The diagram shows a side view of the guide vanes distributed along the axial direction and their tips aligned in this invention.

[0046] Figure 14 The diagram shown is a top view of the guide vanes distributed along the axial direction in this invention.

[0047] Figures 15a to 15f The diagram shown is a schematic of the end plate in this invention.

[0048] Figure 16 The diagram shown is a longitudinal tilting schematic of the pre-rotation combined guide wheel in this invention.

[0049] Figure 17 The diagram shown is a side view of the connector and guide fin in this invention.

[0050] Figure 18 The diagram shown is a top view of the connector and guide fin in this invention.

[0051] Component designation explanation

[0052] Stern section of the hull 1, First guide wheel 2, Second guide wheel 3 and Third guide wheel 4, Left first guide vane 5, Left second guide vane 6, Left third guide vane 7, Right first guide vane 8, Right second guide vane 9, End plate 10, Left half guide wheel 41, Right half guide wheel 43, Connecting guide wheel 42, Connector 11, Transverse plate 111, Longitudinal plate 112, Guide fin 12, Wing planar body 101, Elliptical planar body 102, First wing retractable body 103, Second wing retractable body 104. Detailed Implementation

[0053] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0054] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0055] A schematic diagram of the orientation of the pre-rotation guide wheel of the present invention is shown below. Figure 1 , Figure 2 As shown, the coordinate system is based on the diagram, with the origin located at the center of the propeller shaft. The x-direction is from the center of the propeller shaft to the bow, hence the term "fore" in later text indicates its position is relatively closer to the bow, and vice versa; the y-direction is from the center of the propeller shaft to the left side of the hull, which is positive; the z-direction is from the center of the propeller shaft to the deck, which is positive. Figure 2 As shown, the mid-section (z=0, BB in the figure) serves as the dividing line, vertically dividing the ship into upper and lower parts. The mid-longitudinal section (y=0, AA in the figure) marks the left (port) and right (starboard) sides of the ship, respectively, thus dividing the stern yoz plane into four quadrants. When describing the pre-rotation guide wheel of this invention, the axial, radial, and circumferential directions of a cylindrical coordinate system are used. The origin remains the propeller shaft center, the axial direction is the x-direction, the radial direction r is the direction from the propeller shaft center to the tip of the propeller blade, and the circumferential direction θ is the propeller rotation direction (…). Figure 2 ), with the top of the mid-longitudinal section as 0° and clockwise as positive.

[0056] In addition, unless otherwise specified, when describing variables such as length and distance in the following descriptions of this invention, the propeller radius R shall be used. The propeller is the specific propeller that is matched one by one with the diversion and pre-spinning combined guide wheel involved in this invention. Therefore, different ships have different propeller radii R.

[0057] Figure 3a , Figure 3b This is a contour map of the circumferential flow field velocity magnitude at the yoz section in front of the propeller and behind the stern, along with the directional distribution of the velocity and the outline of the propeller model. Figure 3a This assumes the propeller is not preceded by a pre-spinning guide wheel. Figure 3b This is for the case of a pre-swirl combined guide wheel. Taking a right-handed propeller (clockwise) as an example, to achieve high propeller efficiency, the flow direction in front of the propeller and within its effective range needs to be counter-clockwise, i.e., pre-swirl opposite to the propeller's rotation direction. However, due to the complex shape of the stern and its complete symmetry along the mid-longitudinal section, therefore... Figure 3aThe circumferential velocity along the longitudinal section is completely opposite on the left and right sides. The pre-swirl guide vane only needs to improve the clockwise flow field, i.e., the outer left side and the inner right side, so an asymmetrical arrangement is required to achieve the highest possible energy saving effect. In the radial direction, the circumferential velocity of the flow field may also change from clockwise to counterclockwise, so the guide vanes also need to be changed in the radial direction. The pre-swirl guide vane in this invention will be described in detail below.

[0058] like Figures 4 to 7 As shown, the present invention provides a pre-rotation combined guide wheel for drainage, specifically comprising:

[0059] The ship is divided into left and right sides by the longitudinal section along the propeller shaft. Multiple guide vanes are asymmetrically distributed on both sides. The roots of these guide vanes are fixedly connected to the stern 1 of the hull around the propeller circumferentially. The left side has 3-4 guide vanes, and the right side has 1-2. These guide vanes support the guide wheels and generate a pre-swirling flow that improves propeller propulsion efficiency. Two or more guide vanes are connected circumferentially to the arc-shaped guide wheels. The radial distances between the guide wheels and the propeller shaft can be the same or different. End plates 10 are provided at the ends of some guide vanes furthest from the propeller shaft.

[0060] Taking the longitudinal section containing the propeller shaft as the 0° reference plane, the left / right guide vanes are named left / right first guide vane, second guide vane, third guide vane, etc., according to their angles with the longitudinal section from largest to smallest. The two left guide vanes and one right guide vane closest to the longitudinal section are fixedly connected to the guide wheel, while the remaining guide vanes can be in a free state, reducing the effective range of the guide wheel and preventing it from being connected to the guide vanes. Due to the irregular flow field at the stern, provided the structural strength is sufficient, this free state can avoid the reduction in energy-saving benefits caused by certain parts of the guide wheel being in unfavorable flow areas. The length of the left guide vane is 0.6-1.0R, the length of the right second guide vane is 0.2-1.0R, and the length of the right first guide vane is 0.2-0.6R, significantly shorter than the length of the left guide vane. The lengths of each guide vane may also vary. The guide vanes include left first guide vane 5, left second guide vane 6, left third guide vane 7, right first guide vane 8, and right second guide vane 9.

[0061] Specifically, in the first embodiment, such as Figure 4 As shown, the guide vanes include a first guide vane 2, a second guide vane 3, and a third guide vane 4. The ends of the left first guide vane 5 and the left second guide vane 6 are equipped with end plates 10, while the right second guide vane 9 does not have an end plate. The asymmetrical end plate arrangement is due to cavitation during propeller operation. Cavitation mainly occurs in the upper region, therefore, end plates are added to the upper guide vanes to reduce the vortices formed at the protruding ends, thereby reducing the disturbance of cavitation caused by vortices hitting the propeller surface and mitigating cavitation instability. The area where the right second guide vane 9 is located has no impact on cavitation, therefore no end plate is provided.

[0062] The first guide wheel 2 connects the middle of the left first guide vane 5 and the middle of the left second guide vane 6, with the ends of the left first guide vane 5 and the left second guide vane 6 protruding outwards from the first guide wheel 2. The second guide wheel 3 connects the middle of the two guide vanes closest to the mid-longitudinal section (i.e., the left third guide vane 7 and the right second guide vane 9). The third guide wheel 4 connects the ends of the two guide vanes closest to the mid-longitudinal section (i.e., the left third guide vane 7 and the right second guide vane 9). The second guide wheel 3 has the same radius as the first guide wheel 2, and the two are integrated to form an integrated guide wheel with a vertex radius dr. 12 The range is 0.4-0.6R. The third guide wheel 4 is located on the outer side of the integrated guide wheel, away from the propeller shaft. The vertex radius dr3 of the third guide wheel 4 ranges from 0.75-0.95R. The distance between the third guide wheel 4 and the integrated guide wheel at the mid-longitudinal section is 0.3-0.5R. This will improve the poor wake field near the mid-longitudinal section over a wider area, further improving propeller efficiency. The vertex radius of the guide wheel is the farthest distance between the outer surface of the guide wheel and the center of the propeller shaft.

[0063] Due to the process requirements of installing the connectors, the third guide wheel 4 is welded together from the left half guide wheel 41, the right half guide wheel 43, and the connecting guide wheel 42. The left half guide wheel 41 and the right half guide wheel 43 are arc-shaped, while the connecting guide wheel 42, located between the left half guide wheel 41 and the right half guide wheel 43, is straight and located near the mid-longitudinal section. It is used for further improvements to the arrangement and welding of the connector 11 (see [reference]). Figure 17 The length is 0-0.25R. For adaptability to complex circumferential wake fields, the centers of the various guide wheels may not be at the propeller shaft center, and their radii may differ. Therefore, the circumferential orientation of the guide wheels will deviate from that of the propeller, such as... Figure 5 As shown. The parameter for determining the influence range of the guide wheel is the farthest distance between the outer surface of the guide wheel and the center of the propeller shaft, i.e., the radius dr of the guide wheel vertex.

[0064] In the second embodiment, compared to the first embodiment, the structure of the guide wheel and end plate is changed, and the end of the second guide vane 9 on the right side is contracted inward, while the rest remains unchanged.

[0065] Specifically, such as Figure 6 As shown, the second guide wheel is removed, leaving only the first guide wheel 2 and the third guide wheel 4. The first guide wheel 2 connects the middle of the left first guide vane 5 and the middle of the left second guide vane 6, with the ends of the left first guide vane 5 and the left second guide vane 6 protruding outwards from the first guide wheel 2. The third guide wheel 4 connects the middle of the left third guide vane 7 and the end of the right second guide vane 9. The first guide wheel 2 and the third guide wheel 4 have the same radius and are integrated, with their vertex radius dr. 13The range is 0.45-0.65R. The left guide vane and the guide wheel form a cross connection, and the right second guide vane 9 is located on the inner side of the third guide wheel 4 near the propeller shaft. The ends of the left first guide vane 5, left second guide vane 6, and left third guide vane 7 are provided with end plates, while the ends of the right first guide vane 8 and right second guide vane 9 are not provided with end plates.

[0066] In the third embodiment, compared to the first embodiment, the structure of the guide wheel and end plate is changed, while everything else remains the same.

[0067] Specifically, such as Figure 7 As shown, the second guide wheel is removed, leaving only the first guide wheel 2 and the third guide wheel 4. The first guide wheel 2 connects the end of the left second guide vane 6 and the end of the left third guide vane 7, while the third guide wheel 4 connects the end of the left third guide vane 7 and the end of the right second guide vane 9. The first guide wheel 2 and the third guide wheel 4 have the same radius and are integrated into one unit, with their vertex radius dr. 13 The range is 0.75-0.95R. The guide vanes connected to the guide wheel (i.e., the second guide vane 6 on the left, the third guide vane 7 on the left, and the second guide vane 9 on the right) are all located inside the guide wheel. The first guide vane 5 on the left has an end plate at its end, while the first guide vane 8 on the right, the second guide vane 9 on the right, the second guide vane 6 on the left, and the third guide vane 7 on the left do not have end plates at their ends.

[0068] In the above embodiments, the specific connection form between the guide vane and the guide wheel has been described. The following further defines the outline shape and specific dimensions of the guide vane, guide wheel, and end plate. It should be understood that the following parameter limitations regarding the guide vane, guide wheel, and end plate apply to all three embodiments described above.

[0069] (a) Parameter limitations for the guide wheel.

[0070] like Figure 8 As shown, the radial cross-sectional profile of the guide wheel includes an upper surface, front and rear arcs, and a lower surface. The upper and lower surfaces are either straight lines or convex arcs, and both are tangent to the front and rear arcs. The line connecting the centers of the front and rear arcs is the chord of the guide wheel's cross-section. The angle between the chord and the horizontal line in the plane containing the guide wheel's cross-section is the angle of attack Sα of the guide wheel's cross-section. The length between the two intersection points formed by the extended chord and the front and rear arcs is the chord length c1 (i.e., SL marked in the figure). The radii of the front and rear arcs are Sr1 and Sr2, respectively, with Sr1 ≥ Sr2, to achieve effective airflow guidance. Sb ≥ 2Sr1 to ensure a smooth transition. The maximum thickness of the guide wheel's cross-section is Sb. The intersection points of the measurement line containing the maximum thickness with the upper and lower surfaces are the upper and lower measurement points, respectively. Along the chord direction, the distances from the upper and lower measurement points to the front end point of the front arc are Sc1 and Sc2, respectively.

[0071] The chord length c1 of the guide wheel section is ≤0.6R. Other section parameters involving length are represented by the chord length c1 due to their relatively small magnitude. The range of values ​​for other section parameters is as follows:

[0072] Sα: 0-10°, clockwise is positive;

[0073] Sr1: 0.05-0.1c1; Sr2: 0.005-0.1c1;

[0074] Sb: 0.05-0.15c1;

[0075] Sc1:0.2-0.5c1, with the preceding endpoint as the zero point;

[0076] Sc2:0.2-0.5c1, with the preceding endpoint as the zero point;

[0077] The upper and lower surfaces of the guide wheel are constructed using polynomials / analytic functions t(c) and f(c) for thickness and camber, respectively. The upper and lower surfaces are as follows:

[0078] Y_up(c) = t(c) + f(c);

[0079] Y_down(c) = t(c) - f(c); the value of c is 0-c1.

[0080] By parametrically representing the cross-section and adding constraints such as maximum thickness and front and rear arc radii, the shapes of the upper and lower surfaces under one or more specific optimization objectives can be solved.

[0081] As an example, t(c) = t_max × [a0c (1 / 2) + a1c + a2c 2 + a3c 3 + a4c 4 f(c) = f_max × [b0c + b1c] 2 + b2c 3 + b3c 4 ] t_max is the maximum thickness, and f_max is the maximum camber.

[0082] When the guide wheel is located in a region far from the central longitudinal section, i.e., when the absolute value of the y-coordinate is large, its energy-saving effect is often worse than that of the guide wheel in the central longitudinal section. If the strength is insufficient at this point, and the guide wheel needs to extend to the entire structure, then the guide wheel profiles in the regions far from and near the central longitudinal section can be different, such as... Figure 9 As shown in the diagram (variable cross-section), the angle of attack Sα on the left side gradually decreases, and the difference in radius between the front and rear ends becomes smaller, resulting in a smaller maximum thickness. This design retains the structural function of the guide wheel while avoiding unnecessary drag in areas with favorable flow fields. In other words, the guide wheel section farther from the mid-longitudinal section has a smaller maximum thickness Sb and a smaller angle of attack Sα compared to the guide wheel section closer to the mid-longitudinal section, thus reducing drag by minimizing obstruction to the flow field.

[0083] like Figure 10 As shown, the guide wheel can be stretched a certain distance along the ship's length, meaning the projections of the left and right sides of the guide wheel on the mid-longitudinal section do not coincide. The bold solid line in the figure is the line connecting the midpoints of the guide wheels. The coordinate difference between the left and right ends of the guide wheel along the ship's length (i.e., the x-direction) is the stretching distance p, which is 0-0.15R. The radius rf of the guide wheel's front end can be 1-1.2 times the radius rb of the guide wheel's rear end. In other words, the radius of the guide wheel contracts to a certain extent from front to back, thus concentrating the water flow. Figure 10 The upper guide wheel is shown. The center of the upper guide wheel is located above the center of the propeller shaft.

[0084] (ii) Parameter limitations for guide vanes.

[0085] like Figure 11 As shown, the cross-sectional profile of the guide vane includes a left surface, front and rear circular arcs, and a right surface. The left and right surfaces are either straight lines or convex arcs, and both are tangent to the front and rear circular arcs. The right surface is a convex arc, while the left surface can be either a straight line or a concave-convex arc, and both surfaces are tangent to the front and rear circular arcs. The line connecting the centers of the front and rear circular arcs is the chord of the guide vane cross-section. The angle between the chord and the mid-longitudinal section is the angle of attack Fα of the guide vane cross-section. The length between the two intersection points formed by the chord and the two circular arcs is the chord length c2 (i.e., FL in the figure). The radii of the front and rear circular arcs are Fr1 and Fr2, respectively, with Fr1 > Fr2, to prevent excessive flow separation in the guide vane. The maximum thickness of the guide vane cross-section is Fb. The intersection points of the measurement line containing the maximum thickness with the left and right surfaces are the left and right measurement points, respectively. Along the chord direction, the distances from the left and right measurement points to the front end of the front circular arc are Fc1 and Fc2, respectively, with Fb ≥ 2Fr1, to ensure a smooth transition. The construction of the left and right surfaces of the guide vane and the optimization of its parameters are the same as those of the guide wheel.

[0086] The guide vane section chord length c2 ≤ 0.6R. Other section parameters involving length are represented by chord length c2 due to their relatively small magnitude. The range of values ​​for other section parameters is as follows:

[0087] Fα: -25 to 25°, clockwise is positive;

[0088] Fr1: 0.02-0.05c2; Fr2: 0.005-0.02c2;

[0089] Fb: 0.05-0.15c2;

[0090] Fc1:0.1-0.9c2, with the preceding endpoint as the zero point;

[0091] Fc2:0.1-0.9c2, with the preceding endpoint as the zero point;

[0092] Along the radial direction, with any point on the line connecting the inlet and outlet of the airfoil as the base point, the guide vane gradually tapers from the root to the tip. The chord length at the tip of the guide vane is 0.5-1 times the chord length at the root, forming a guide vane as a whole that continuously tapers from root to tip. Furthermore, the parameters of the guide vane cross-section can vary radially to conform to the radially varying circumferential flow field and the characteristics of the propeller on both sides. Figure 12 As shown, the angle of attack and shape of the three guide vane sections (upper, middle, and lower) selected sequentially from the tip to the root are different, in order to cope with... Figure 3a Flow field characteristics such as abrupt changes in velocity in the mid-circumferential direction.

[0093] The angle between the first guide vane on the left and the mid-longitudinal section is 65-140°, and the angle between the remaining guide vanes on the left is 20-45°; the angle between the first guide vane on the right and the mid-longitudinal section is 20-140°, and the angle between the second guide vane on the right and the mid-longitudinal section is 20-45°, in order to avoid the blade cascade effect caused by the dense distribution of guide vanes, which would significantly increase drag.

[0094] The guide vanes can be partially or entirely distributed along the axial direction, or they can be distributed non-axially, meaning the x-coordinates of the guide vanes are equal. Since the shapes of the guide vanes may differ, the root end closest to the propeller is used as the reference. The axial spacing between the guide vanes is 0-0.05R; the first guide vane on the left is closest to the propeller disk, at a distance of 0.2-0.6R, meaning the first guide vane on the left is further back than the other guide vanes.

[0095] Figure 13 , 14 The diagrams show five axial arrangement schemes of guide vanes, with three guide vanes on the left and two on the right, viewed from left and top views respectively. Scheme 1 shows the left guide vane gradually moving forward from near the propeller until it is the same as the right guide vane; Scheme 2 shows only the first guide vane on the left moving backward; Scheme 3 shows staggered guide vanes with the first guide vane on the left fixed close to the propeller; Scheme 4 shows the first guide vane on the left moving even closer to the propeller compared to Scheme 3; and Scheme 5 shows the guide vanes gradually moving forward from left to right.

[0096] Dij represents the distance along the ship's length between the leading ends of the j-th leading guide vane and the (j+1)-th leading guide vane in the i-th guide vane arrangement. Each arrangement and distance is based on a multiple of the propeller radius R. The arrangement schemes and their value ranges are defined as follows:

[0097] In the first guide vane arrangement, the third guide vane 7 on the left, the first guide vane 8 on the right, and the second guide vane 9 on the right are all the first leading guide vanes, the second guide vane 6 on the left is the second leading guide vane, and the first guide vane 5 on the left is the third leading guide vane. D11: 0-0.03R, D12: 0-0.02R, and D11>D12.

[0098] In the second guide vane arrangement, the second guide vane 6 on the left, the third guide vane 7 on the left, the first guide vane 8 on the right, and the second guide vane 9 on the right are all the first leading guide vanes, while the first guide vane 5 on the left is the second leading guide vane. D21: 0-0.02R.

[0099] In the third guide vane arrangement, the second guide vane 6 on the left and the second guide vane 9 on the right are both the first leading guide vanes, and the first guide vane 5 on the left, the third guide vane 7 on the left, and the first guide vane 8 on the right are both the second leading guide vanes. D31: 0-0.04R.

[0100] In the fourth guide vane arrangement, the second guide vane 6 on the left and the second guide vane 9 on the right are both the first leading guide vanes, the third guide vane 7 on the left and the first guide vane 8 on the right are both the second leading guide vanes, and the first guide vane 5 on the left is the third leading guide vane. D41: 0-0.05R, D12: 0-0.02R, and D41>D12.

[0101] In the fifth guide vane arrangement, the first guide vane 8 and the second guide vane 9 on the right are both the first forward guide vanes, the third guide vane 7 on the left is the second forward guide vane, the second guide vane 6 on the left is the third forward guide vane, and the first guide vane 5 on the left is the fourth forward guide vane. D51: 0-0.01R; D53: 0-0.03R; and D51 gradually increases to D53.

[0102] In addition to moving as a whole along the propeller shaft axially, the guide vane tip can also translate axially independently, allowing the guide vane to be stretched into a forward or backward sweeping shape. Since propeller cavitation largely adheres to surfaces above 0.6R, and as each blade rotates to different flow field ranges with significant circumferential differences, the attached cavitation changes accordingly, leading to severe vibrations that can damage the ship's structure. In this invention, while the root of the guide vane is distributed forward and backward along the axial direction, the blade tip (guide vane end) is located at the same position axially, with a linear transition between the root and tip. This considers both the circumferential velocity of the flow field, improving energy efficiency, and maintains the consistency of the flow field at the blade tip, ensuring that the impact of cavitation and pulsating pressure on the ship remains essentially unchanged. Figure 14 As shown.

[0103] (iii) Parameter limitations for end plates.

[0104] The cross-sectional shape of the end plate includes, but is not limited to, elliptical, airfoil-shaped (pointed at the front and rounded at the rear), etc., and the structural forms include both planar and contracted bodies. A typical structure of end plate 10 is shown below. Figures 15a to 15d As shown, the planar body includes an airfoil planar body 101 and an elliptical planar body 102. The planar body is obtained by simple extrusion of a plane, and its chord length c3 is 1.1-1.2 times the chord length of the guide vane tip. If the planar body is an airfoil planar body, then the cross-sectional shape of the guide vane tip is continued and enlarged proportionally by 1.1-1.2 times.

[0105] The retractable body includes two forms: the first wing retractable body 103 and the second wing retractable body 104.

[0106] If the flow velocity at the location is high, the upper surface of the planar body is three-dimensionally stretched into an upper curved surface, transforming the planar body into a contracted body. The stretching height, i.e., the height difference h3 between the highest and lowest points of the upper curved surface, is 0.05-0.1R. The cross-sectional shape of the contracted body remains airfoil-shaped, and the upper curved surface of the contracted body is streamlined with a lower front and higher rear. In the first airfoil contracted body 103, the top edge of the upper curved surface tapers into an airfoil-shaped opening; while in the second airfoil contracted body 104, the top edge of the upper curved surface tapers into a pointed tip.

[0107] The curved surface design ensures a smooth transition of the incoming flow as it passes through the end plate, reducing flow separation. The top edge of the curved surface tapers from 0 to 0.2c3 (0 meaning it tapers to a cusp), corresponding to different structural strength requirements. Figure 15c Shrink to 0.15c3, Figure 15d It shrinks into a single point. Figure 15e , Figure 15f This is a 3D diagram showing two contraction patterns. Additionally, since the main body of the vortex is located on the right side of the guide vane tip, the endplate will translate a certain distance to the right side of the guide vane tip to cover the area where the vortex appears.

[0108] Furthermore, based on the above structural design, the present invention also makes certain deformations to the overall guide wheel for pre-rotation.

[0109] like Figure 16 As shown, the drainage pre-rotation combined guide wheel involved in this invention rotates clockwise around the y-axis by a certain angle, that is, it forms a longitudinal tilt angle β relative to the yoz plane, and the longitudinal tilt angle β ranges from -5 to 15°.

[0110] Figure 17 , Figure 18 The diagram shows a schematic of the structure of the pre-swirl guide wheel with added connectors and some guide fins in this invention. When the structural strength is insufficient or the main body cannot adequately improve the flow field, the invention is connected and fixed to the stern 1 of the hull via connector 11, and multiple guide fins 12 are provided at the stern 1. Connector 11 includes a transverse plate 111 and a longitudinal plate 112 located in the mid-longitudinal section. The guide fins are slender fin-like bodies located in front of the connector and fixed to the stern surface. The number of fins, their arrangement angle, and their position in the z-direction vary depending on the hull type. Guide fins 12 are only arranged on the right side, and one of the guide fins is integrally connected to connector 11. Figure 18As shown, the right-side transverse plate 111 and the integrated guide fin 12 have the same thickness, and the guide fin 12 gradually tapers in an arc shape. This arrangement enhances the guiding effect, further improves the flow field, and also strengthens the overall structure of the invention, playing a complementary role. The thickness of the left-side transverse connector remains unchanged. The guide fins make an angle of -10° to 10° with the x-direction, and multiple guide fins 12 are parallel to each other. In this embodiment, there are two guide fins, with the lower guide fin along the z-direction being wider. By altering the upstream flow field of the propeller, it improves the inherently poor wake field of certain ship types, and can serve as an auxiliary energy-saving device for the propeller.

[0111] The design method of the pre-rotation combined guide wheel in this invention specifically includes the following steps:

[0112] 1: Calculate the three-dimensional flow field information of the propeller disk surface (located at the center of the hub, the circular area swept by the blades when the propeller rotates) and its surroundings using CFD.

[0113] 2: Using flow field information as one of the constraints, the guide wheel and propeller designed in this invention are calculated together in a specific CFD scheme. Under different propeller models, the parameters mentioned in this invention are optimized to obtain the guide wheel scheme corresponding to the propeller model.

[0114] 3: Using flow field information as one of the constraints, import it into a specific CFD scheme or potential flow theory calculation program to calculate the guide vane (with endplate) and propeller designed in this invention together. Under different propeller models, optimize the various parameters mentioned in this invention to obtain the guide vane scheme corresponding to the propeller model.

[0115] 4: After combining the guide wheel and guide vane, a combined guide wheel scheme is obtained. CFD self-propulsion simulation is performed on each scheme to verify its energy-saving effect and flow field improvement. If the effect is not good, guide fins are added and the simulation is repeated to obtain a preliminary scheme.

[0116] 5. Several preliminary designs will be tested on ship models to verify their energy-saving effects and other performance indicators. If the results are unsatisfactory, the designs will be improved and retested to obtain the final shape design.

[0117] In summary, this invention provides a combined guide wheel and vessel for diversion and pre-spinning. This combined guide wheel achieves the basic requirements of improving the flow field around the stern and propeller, and increasing propeller efficiency. Furthermore, by arranging the guide vanes axially, it reduces the stress on the structure, increasing energy-saving effects. Simultaneously, end alignment avoids the negative impact of axial misalignment on propeller pulsating pressure. In addition, by limiting the circumference length of the guide wheel, the resistance generated by the device is reduced, thus improving the resistance and structural performance of the energy-saving device. Through various combinations of guide wheels, guide vanes, connectors, and guide fins, and by establishing a design method that matches each combination of this invention, superior energy-saving effects can be achieved for different ship types and navigation conditions. It realizes effective complementarity among multiple structures and has strong versatility.

[0118] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A pre-rotating guide wheel for drainage, characterized in that, The ship is divided into left and right sides by the longitudinal section where the propeller shaft is located. Multiple guide vanes are asymmetrically distributed on the left and right sides. The roots of the multiple guide vanes are fixedly connected to the stern of the hull around the propeller. There are 3-4 guide vanes on the left side and 1-2 guide vanes on the right side. The guide vanes are used to support the guide wheel and generate a pre-swirl that is beneficial to the propeller propulsion efficiency. The arc-shaped guide wheel is connected to two or more guide vanes around the circumference. Some guide vanes have end plates at the ends away from the propeller shaft. With the propeller shaft's longitudinal section as the 0° reference plane, the left / right guide vanes are named left / right first guide vane, second guide vane, third guide vane, etc., according to their angles with the longitudinal section from largest to smallest. The two left guide vanes and one right guide vane closest to the longitudinal section are fixedly connected to the guide wheel. The roots of the multiple guide vanes are distributed back and forth along the axial direction, and the ends of the multiple guide vanes are located at the same position in the axial direction, with a linear transition between the roots and the ends. The guide vanes include a first guide vane on the left, a second guide vane on the left, a third guide vane on the left, a first guide vane on the right, and a second guide vane on the right; the propeller radius is defined as R; the cross-sectional profile of the guide vanes includes a left surface, a front and rear circular arc, and a right surface, with both left and right surfaces tangent to the front and rear circular arcs; the right surface is a convex arc, and the left surface is a straight line or a concave-convex arc, with both left and right surfaces tangent to the front and rear circular arcs; the line connecting the centers of the front and rear circular arcs is the chord of the guide vane cross-section, and the angle between the chord and the mid-longitudinal section is the angle of attack Fα of the guide vane cross-section; the chord is extended... The length between the two intersection points formed by the front and rear arcs is the chord length c2; the radii of the front and rear arcs are Fr1 and Fr2, respectively, and Fr1 > Fr2, to prevent excessive flow separation from the guide vane; the maximum thickness of the guide vane section is Fb, and the intersection points of the measurement line where the maximum thickness is located with the left and right surfaces are the left measurement point and the right measurement point, respectively. Along the chord direction, the distances between the left measurement point and the right measurement point and the front end point of the front arc are Fc1 and Fc2, respectively, and Fb ≥ 2Fr1. The chord length c2 of the guide vane section is ≤ 0.6R.

2. The pre-rotation guide wheel according to claim 1, characterized in that: The length of the left guide vane is 0.6-1.0R, the length of the right second guide vane is 0.2-1.0R, and the length of the right first guide vane is 0.2-0.6R, which is less than the length of the left guide vane.

3. The pre-rotation guide wheel according to claim 1, characterized in that: The guide wheel includes a first guide wheel, a second guide wheel, and a third guide wheel. The ends of the left first guide vane and the left second guide vane are provided with end plates, while the right second guide vane is not provided with an end plate. The first guide wheel connects the middle of the first guide vane on the left and the middle of the second guide vane on the left. The second guide wheel connects the middle of the third guide vane on the left and the second guide vane on the right. The third guide wheel connects the ends of the third guide vane on the left and the second guide vane on the right. The second guide wheel has the same radius as the first guide wheel. The two are connected as a whole to form an integrated guide wheel. The vertex radius of the integrated guide wheel is in the range of 0.4-0.6R. The third guide wheel is located on the outer side of the integrated guide wheel, away from the propeller shaft. The vertex radius of the third guide wheel ranges from 0.75 to 0.95R, and the distance between the third guide wheel and the integrated guide wheel at the mid-longitudinal section is 0.3 to 0.5R.

4. The pre-rotation combined guide wheel according to claim 1, characterized in that: The guide wheel includes a first guide wheel and a third guide wheel. The first guide wheel connects the middle of the left first guide vane and the middle of the left second guide vane, and the third guide wheel connects the middle of the left third guide vane and the end of the right second guide vane. The first and third guide wheels have the same radius and are integrated, with their vertex radius ranging from 0.45 to 0.65R. The left guide vane and the guide wheel are cross-connected, and the right second guide vane is located on the inner side of the third guide wheel near the propeller shaft. The ends of the left first guide vane, left second guide vane, and left third guide vane are provided with end plates, while the ends of the right first guide vane and right second guide vane are not provided with end plates.

5. The pre-rotation combined guide wheel according to claim 1, characterized in that: The guide wheel includes a first guide wheel and a third guide wheel. The first guide wheel connects the end of the second guide vane on the left and the end of the third guide vane on the left. The third guide wheel connects the end of the third guide vane on the left and the end of the second guide vane on the right. The first guide wheel and the third guide wheel have the same radius and are integrated into one piece. Their vertex radius ranges from 0.75 to 0.95R. The second guide vane on the left, the third guide vane on the left, and the second guide vane on the right are all located inside the guide wheel. The end of the first guide vane on the left is provided with an end plate, while the ends of the first guide vane on the right, the second guide vane on the right, the second guide vane on the left, and the third guide vane on the left are not provided with end plates.

6. The pre-rotation combined guide wheel according to claim 1, characterized in that: The radial cross-sectional profile of the guide wheel includes an upper surface, front and rear circular arcs, and a lower surface. The upper and lower surfaces are straight lines or convex arcs, and both the upper and lower surfaces are tangent to the front and rear circular arcs. The line connecting the centers of the front and rear arcs is the chord of the guide wheel section. The angle between the chord and the horizontal line in the plane containing the guide wheel section is the angle of attack Sα of the guide wheel section. The length between the two intersection points formed by the extended chord and the front and rear arcs is the chord length c1. The radii of the front and rear arcs are Sr1 and Sr2, respectively, and Sr1≥Sr2 to achieve effective airflow guidance of the guide wheel. Sb≥2Sr1 to ensure a smooth transition. The maximum thickness of the guide wheel section is Sb. The intersection of the measurement line where the maximum thickness is located with the upper and lower surfaces is the upper measurement point and the lower measurement point. Along the chord direction, the distances between the upper measurement point and the lower measurement point and the front end point of the front arc are Sc1 and Sc2, respectively. The chord length of the guide wheel section is c1≤0.6R.

7. The pre-rotation guide wheel according to claim 6, characterized in that: The guide wheel section farther from the center longitudinal section has a smaller maximum thickness Sb compared to the guide wheel section closer to the center longitudinal section.

8. The pre-rotation guide wheel according to claim 6, characterized in that: The projections of the left and right sides of the guide wheel on the mid-longitudinal section do not coincide; the coordinate difference between the left and right ends of the guide wheel along the ship's length is the stretching distance p, which is 0-0.15R.

9. The pre-rotation guide wheel according to claim 6, characterized in that: From front to back, the radius of the guide wheel gradually decreases; the radius rf of the front end of the guide wheel is 1-1.2 times the radius rb of the rear end of the guide wheel.

10. The pre-rotation guide wheel according to claim 1, characterized in that: Along the radial direction of the propeller shaft, the guide vane gradually contracts from the root to the tip, and the chord length of the guide vane tip is 0.5-1 times that of the chord length of the guide vane root, forming a guide vane whole that continuously contracts from the root to the tip.

11. The pre-rotation guide wheel according to claim 1, characterized in that: Dij represents the distance along the length of the ship between the leading ends of the j-th leading guide vane and the (j+1)-th leading guide vane in the i-th guide vane arrangement. In the first guide vane arrangement, the third guide vane on the left, the first guide vane on the right, and the second guide vane on the right are all the first forward guide vanes, the second guide vane on the left is the second forward guide vane, and the first guide vane on the left is the third forward guide vane; D11: 0-0.03R, D12: 0-0.02R, and D11>D12; In the second guide vane arrangement, the second guide vane on the left, the third guide vane on the left, the first guide vane on the right, and the second guide vane on the right are all the first forward guide vanes, and the first guide vane on the left is the second forward guide vane; D21:0-0.02R; In the third guide vane arrangement, the second guide vane on the left and the second guide vane on the right are simultaneously the first forward guide vanes, and the first guide vane on the left, the third guide vane on the left, and the first guide vane on the right are simultaneously the second forward guide vanes; D31:0-0.04R; In the fourth guide vane arrangement, the second guide vane on the left and the second guide vane on the right are both the first forward guide vanes, the third guide vane on the left and the first guide vane on the right are both the second forward guide vanes, and the first guide vane on the left is the third forward guide vane; D41: 0-0.05R, D42: 0-0.02R, and D41> D42; In the fifth guide vane arrangement, the first and second guide vanes on the right are simultaneously the first forward guide vanes, the third guide vane on the left is the second forward guide vane, the second guide vane on the left is the third forward guide vane, and the first guide vane on the left is the fourth forward guide vane; D51: 0-0.01R; D53: 0-0.03R; and D51 gradually increases to D53.

12. The pre-rotation guide wheel according to claim 1, characterized in that: The cross-sectional shape of the end plate includes elliptical and airfoil-shaped with a pointed front and rounded rear; the structural form of the end plate includes planar body and contracted body; The upper surface of the planar body is three-dimensionally stretched into an upper curved surface, transforming the planar body into a contracted body. The cross-sectional shape of the contracted body remains airfoil-shaped, and the upper curved surface of the contracted body is streamlined with a lower front and a higher back. The top edge of the upper curved surface tapers into a cusp or an airfoil-shaped opening.

13. The pre-rotation guide wheel according to claim 1, characterized in that: The y-direction is positive from the center of the propeller shaft to the left side of the hull; the z-direction is positive from the center of the propeller shaft to the deck; the guide wheel of the pre-rotation combination forms a pitch angle β relative to the yoz plane, and the pitch angle β ranges from -5 to 15°.

14. The pre-rotation guide wheel according to claim 1, characterized in that: The pre-rotation guide wheel is connected and fixed to the stern of the hull via a connector, and multiple guide fins are set at the stern of the hull, with the multiple guide fins parallel to each other; the guide fins are only arranged on the right side, and one of the guide fins is integrated with the connector.

15. A ship, characterized in that: The vessel is equipped with a pre-rotation guide wheel as described in any one of claims 1-14.

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