Bionic propeller based on dolphin dorsal fin shape leaf section and blade

Abstract

The invention provides a bionic propeller based on a dolphin dorsal fin shape blade section and a paddle, the blade section of the paddle comprises a blade back and a blade surface, the blade back comprises two body parts and a dorsal fin part located between the two body parts, one ends of the two body parts are connected to the two opposite ends of the blade surface respectively, and the other ends of the two body parts are connected to the dorsal fin part. The dorsal fin part comprises an ascending section and a downward bent section which are sequentially connected in the blade width direction of the paddle, and the end, away from the downward bent section, of the ascending section and the end, away from the ascending section, of the downward bent section are connected with the other ends of the two body parts correspondingly, so that a wing-shaped structure in the shape of a dolphin is formed. The problems of insufficient performance and cavitation effect of a traditional propeller can be solved, so that the propelling efficiency of the propeller is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ship engineering, and in particular to a bionic propeller and a blade based on a blade section of a dolphin dorsal fin shape. Background Art

[0002] With the booming global shipping industry, ships, as crucial vehicles for cargo and personnel transport, are attracting increasing attention for their operational efficiency and environmental performance. Marine propellers, the core component of a ship's propulsion system and the "heart" of the vessel, directly impact its navigation efficiency, energy consumption, and environmental impact. Propellers, also critical propulsion components in the fields of ships and underwater vehicles, are also crucial, and their performance directly impacts key performance indicators such as propulsion efficiency, energy consumption, and noise.

[0003] Conventional propeller airfoils present numerous technical challenges in practical applications. Their performance is significantly deficient. Traditional propeller airfoil designs are largely based on classical fluid mechanics. Under normal operating conditions, boundary layer separation easily occurs as water flows over the airfoil surface. This directly leads to significant energy losses and significantly reduces propulsion efficiency. When a vessel navigates complex sea conditions, such as those encountering currents of varying speeds and directions, conventional propeller airfoils struggle to adapt adaptively, further exacerbating energy losses and significantly increasing the vessel's energy costs. Furthermore, cavitation poses a significant challenge. During high-speed propeller operation, the local pressure on the blade surface decreases. When the pressure drops below the vapor pressure of water, cavitation bubbles form. The collapse of these bubbles generates a powerful impact force, which repeatedly acts on the blade surface, causing material damage and shortening the propeller's service life. This force also leads to additional energy losses. Furthermore, the noise generated by cavitation pollutes the underwater acoustic environment, interfering with the proper functioning of the vessel's acoustic detection equipment. These factors severely hinder improvements in vessel performance. Summary of the Invention

[0004] In order to solve the technical problems raised in the background technology, the present invention provides a bionic propeller blade based on the blade section of a dolphin dorsal fin to solve the problems of insufficient performance and cavitation effect of traditional propellers, thereby improving the propulsion efficiency of the propeller.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A bionic propeller blade based on a blade section with a dolphin dorsal fin shape, the blade section comprising a blade back and a blade surface, the blade back comprising two main body portions and a dorsal fin portion located between the two main body portions, one end of the two main body portions being respectively connected to opposite ends of the blade surface, the dorsal fin portion comprising an ascending section and a descending section connected in sequence along the blade width direction, one end of the ascending section away from the descending section and one end of the descending section away from the ascending section being respectively connected to the other ends of the two main body portions to form an airfoil structure with a dolphin outer shape.

[0007] Furthermore, a two-dimensional local coordinate system OXY of the blade section profile value point of the blade is set, wherein the origin O is the tangent point of the spiral line and the blade section, the blade width direction along the blade section is the OX axis, the direction perpendicular to the OX axis and pointing to the blade back or blade surface is the OY axis, the X coordinate value is expressed in % of the blade width, is the horizontal coordinate of the blade section profile value point, the vertical coordinate Y coordinate value is expressed in % of the maximum vertical distance between the main body and the blade surface, the vertical coordinate of the blade back is expressed as Y0, and the vertical coordinate of the blade surface is expressed as Y U ; The dorsal fin portion is formed in the range of X=30% to 40%, the rising section is in the range of X=30% to 34%, and the vertical coordinate Y0 of the back of the leaf of the rising section rises from 100% to 130% in the range of X=30% to 34%, the downward bending section is in the range of X=34% to 40%, and gradually bends downward from the range of X=34% to 40%, thereby forming a dolphin dorsal fin-shaped geometric mutation.

[0008] Furthermore, in the range of X=30% to 40%, the surface slope of the dorsal fin portion changes as follows:

[0009] In the interval X=30%→34%, the slope of the back surface of the ascending section is (130-100) / (34-30)=7.5, so that the back surface of the blade forms an upward deflection angle of arctan(7.5)≈82.4;

[0010] In the range of X=34%→40%, the slope of the back surface of the downward curved section is (98.33-130) / (40-34)≈-5.278, so that the back surface of the blade forms a downward deflection angle of arctan(-5.278)≈-79.31°.

[0011] Furthermore, the two-dimensional airfoil data of the blade section are shown in the following table:

[0012] X 0 10 20 25 30 32 34 36 38 40 45 50 60 70 80 90 100 <![CDATA[Y0]]> 37.6 89.1 97.8 98.6 100 116 130 129 112 98.3 94.6 94.1 88 80.5 71.8 62.1 51.1 <![CDATA[Y U ]]> 37.6 10.9 2.2 1.5 0 0.08 0.25 0.31 0.42 1.66 4.12 5.92 12 19.5 28.2 37.9 51.1

[0013] Furthermore, in the interval of X=30%→40%, the interpolation density of the two-dimensional local type value points of the leaf section is greater than the interpolation density of the two-dimensional local type value points in the interval of X=0-30% and the interval of X=40-100%.

[0014] The present invention further provides a bionic propeller comprising the blade and having a blade section based on the shape of a dolphin dorsal fin.

[0015] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0016] The above-mentioned bionic propeller and blade based on the blade section of the dolphin dorsal fin are designed by imitating the rounded transition shape of the dolphin dorsal fin. The dolphin's body contour can effectively reduce the friction resistance between the dolphin and the water flow when swimming at high speed, reduce energy loss, and integrate the dolphin's appearance characteristics into the propeller's blade section design. By simulating the curve changes on the dorsal fin surface of the dolphin's body, the shape of the blade section is optimized, so that the water flow can adhere to the blade surface more smoothly when flowing through the blade, reducing the boundary layer separation phenomenon, reducing energy loss, and thus improving the propeller's propulsion efficiency, thereby greatly reducing energy consumption and improving the vehicle's endurance. At the same time, the anti-cavitation performance is significantly enhanced, the degree of cavitation erosion of the blade is greatly reduced, reducing the maintenance and replacement frequency, increasing the lifespan, and reducing the cycle cost, thereby improving the comprehensive performance of ships and underwater vehicles under various working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the main structure of a bionic propeller based on the blade section of a dolphin dorsal fin shape according to a preferred embodiment of the present invention.

[0018] Figure 2 for Figure 1 Right view of .

[0019] Figure 3 This is a schematic structural diagram of the blade of a bionic propeller based on the blade section of a dolphin dorsal fin shape according to a preferred embodiment of the present invention.

[0020] Figure 4 for Figure 3 Plan view of a section of the blade shown.

[0021] Explanation of the main component symbols: 100, bionic propeller; 10, hub; 30, blade; 31, blade section; 311, blade back; 312, main body; 313, dorsal fin; 314, rising section; 315, downward curved section; 317, blade surface. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a central component. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0025] Please also see Figures 1 to 4 A preferred embodiment of the present invention provides a bionic propeller 100 based on a blade section of a dolphin dorsal fin shape, comprising a hub 10 and a plurality of blades 30 spaced circumferentially along the hub 10, one end of each blade 30 being fixedly connected to the outer peripheral wall of the hub 10. In this embodiment, the propeller shape of the bionic propeller 100 is based on the AU-type propeller. By redesigning the blade section 31 of the blade 30 of the AU-type propeller, combining it with the NACA0012 airfoil as a basis and referring to the shape of a dolphin, a new propeller blade is obtained to further improve the overall performance of the propeller. The AU-type propeller has shown certain advantages in past practice, and its propeller shape design is based on in-depth research on the hydrodynamic performance of the propeller. The structural design of the AU-type propeller can optimize the interaction between the water flow and the blade to a certain extent, so that the propeller can more effectively convert the rotational mechanical energy into the kinetic energy of the fluid during the rotation process, thereby propelling the vehicle forward. The blade section elements and blade profile dimensions of the AU-type propeller used in this embodiment are shown in Tables 1 and 2.

[0026]

[0027] Table 1

[0028]

[0029] Table 2

[0030] The blade section 31 of the blade 30 obtained by improving the blade section of the AU-type propeller in this embodiment includes a blade back 311 and a blade surface 317. Blade back 311 includes two main bodies 312 and a dorsal fin 313 located between the two main bodies 312. One end of the two main bodies 312 is connected to opposite ends of the blade surface 317. The dorsal fin 313 includes an ascending section 314 and a descending section 315 connected in sequence along the width of the blade 30. The end of the ascending section 314 remote from the descending section 315 and the end of the descending section 315 remote from the ascending section 314 are respectively connected to the other ends of the two main bodies 312, forming a dolphin-shaped airfoil structure.

[0031] Specifically, a two-dimensional local coordinate system OXY of the profile point of the blade section 31 of the blade 30 is assumed, wherein the origin O is the tangent point of the helix and the blade section 31, wherein the helix is ​​the trajectory line formed by each point on the propeller blade during the rotation process. Specifically, it refers to the curve formed when a certain point on the blade (such as a point on the edge of the blade) moves simultaneously along the axial and circumferential directions of the propeller when the propeller rotates. The blade width direction along the blade section 31 of the blade 30 is the OX axis, and the direction perpendicular to the OX axis and pointing to the back 311 or the blade surface 317 of the blade 30 is the OY axis. The X coordinate value is expressed in % of the blade width, is the horizontal coordinate of the profile point of the blade section 31, and the coordinate value of the vertical coordinate Y of the profile point of the blade section 31 is expressed in % of the maximum vertical distance between the main body 312 and the blade surface 317. Wherein, the vertical coordinate of the back 311 is expressed as Y0, and the vertical coordinate of the blade surface 317 is expressed as Y U The two-dimensional airfoil data of the blade section 31 of the improved blade 30 are shown in Table 3 below:

[0032] X 0 10 20 25 30 32 34 36 38 40 45 50 60 70 80 90 100 <![CDATA[Y0]]> 37.6 89.1 97.8 98.6 100 116 130 129 112 98.3 94.6 94.1 88 80.5 71.8 62.1 51.1 <![CDATA[Y U ]]> 37.6 10.9 2.2 1.5 0 0.08 0.25 0.31 0.42 1.66 4.12 5.92 12 19.5 28.2 37.9 51.1

[0033] From Table 3 and Figure 4 It can be seen that in this embodiment, the dorsal fin portion 313 is formed in the range of X = 30% to 40%, wherein the rising section 314 is in the range of X = 30% to 34%, and the vertical coordinate Y0 of the blade back 311 of the rising section 314 rises from 100% to 130% within the range of X = 30% to 34%. The downward curved section 315 is in the range of X = 34% to 40%, and gradually curves downward from the range of X = 34% to 40%, thereby forming a dolphin dorsal fin-like geometric mutation. Specifically, in the range of X = 30% to 40%, the surface slope of the dorsal fin portion 313 of the blade 30 changes as follows:

[0034] In the range of X=30%→34%, the slope of the back surface of the ascending section 314 of the blade 30 is (130-100) / (34-30)=7.5, so that the back surface of the blade 30 forms an upward deflection angle of arctan(7.5)≈82.4.

[0035] In the range of X=34%→40%, the slope of the back surface of the downward curved section 315 of the blade 30 is (98.33-130) / (40-34)≈-5.278, so that the back surface of the blade 30 forms a downward deflection angle of arctan(-5.278)≈-79.31°.

[0036] In the design of propeller airfoils, the selection of angle parameters has always been a key challenge in balancing fluid dynamics performance and engineering feasibility. In order to systematically verify the unique advantages of biomorphic bionic design in breaking through the traditional "performance-process trade-off", and then reveal the quantitative correlation mechanism between fluid dynamics parameters and engineering feasibility. The present invention compares the deflection angles of classic traditional airfoils such as "-60°, -85°, -90°" as reference benchmarks, and finds that the downward deflection angle of -79.31° achieves the optimal balance in terms of propulsion efficiency, cavitation threshold speed, turbulence intensity control and processing cost. Its innovation lies in the cross-integration of biomorphic bionics and fluid dynamics calculations to construct a quantitative mapping relationship between angle parameters and comprehensive performance, breaking through the empirical dependence of angle selection in traditional airfoil design. By drawing the corresponding dolphin cross-section diagram, the data required for airfoil modeling is extracted from it. The measured convex angle of the dolphin's dorsal fin is about 80° to 85°, which ensures the fluid similarity of the bionic structure. At the downward deflection angle, it forms a symmetrical "convex front and concave back" shape with the ascending section, making the pressure distribution of the entire dorsal fin more uniform, thereby solving the problems of insufficient performance and cavitation effect of traditional propellers and improving the propeller's propulsion efficiency.

[0037] Furthermore, within the interval X = 30% → 40%, the interpolation density of the two-dimensional local profile points of the leaf section 31 is greater than the interpolation density of the two-dimensional local profile points within the interval X = 0-30% and the interval X = 40-100%. Specifically, in this embodiment, within the interval X = 30% → 40%, a two-dimensional local profile point is set for every 2% interval of the X value; within the interval X = 30% → 40% and the interval X = 40-100%, a two-dimensional local profile point is set for every 5% or 10% interval of the X value.

[0038] After obtaining the optimized two-dimensional airfoil data shown in Table 3, the coordinates of the two-dimensional local shape value points in the two-dimensional airfoil data can be converted to three-dimensional global shape value points through operations such as translation and torsion angle transformation, thereby constructing a complete three-dimensional model of the propeller. Constructing a three-dimensional propeller model using three-dimensional global shape value points can be performed in software such as MATLAB, SolidWorks, and UG. The steps of converting the coordinates of the two-dimensional local shape value points to three-dimensional global shape value points and constructing a three-dimensional propeller model based on the three-dimensional global shape value points are prior art and will not be repeated here to save space.

[0039] The blade 30 of the bionic propeller 100 based on the blade section 31 of the dolphin dorsal fin shape is designed by imitating the rounded transition shape of the dolphin dorsal fin. The body contour of the dolphin can effectively reduce the friction resistance between the blade 30 and the water flow when swimming at high speed, reducing energy loss. The dolphin shape characteristics are integrated into the design of the blade section 31 of the propeller 100. By simulating the curve changes of the dorsal fin surface of the dolphin body, the shape of the section of the blade 30 is optimized, so that the water flow can adhere to the surface of the blade 30 more smoothly when flowing through the blade 30, reducing the boundary layer separation phenomenon, reducing energy loss, and thus improving the propulsion efficiency of the propeller 100, thereby greatly reducing energy consumption and improving the endurance of the vehicle. At the same time, the anti-cavitation performance is significantly enhanced, the degree of cavitation erosion of the blade 30 is greatly reduced, reducing the maintenance and replacement frequency, increasing the service life, and reducing the cycle cost, thereby improving the comprehensive performance of ships and underwater vehicles under various working conditions.

[0040] In addition, the interpolation density of the blade 30 of the bionic propeller 100 based on the dolphin dorsal fin-shaped blade section 31 is significantly increased in the X=30-40% range (chord length 30% to 40% position). The reason is that this area usually corresponds to the area behind the leading edge of the airfoil to the maximum thickness position, which is a key area for flow separation and pressure gradient change. By increasing the interpolation density, the pressure distribution and flow characteristics of the water flow in this area can be captured more accurately.

[0041] The above description is a detailed description of the preferred embodiments of the present invention, but the embodiments are not intended to limit the scope of the patent application of the present invention. Any equivalent changes or modifications completed under the technical spirit suggested by the present invention should fall within the patent scope covered by the present invention.

Claims

1. A bionic propeller blade based on the cross-section of a dolphin's dorsal fin, characterized in that: The blade section of the blade includes a blade back and a blade surface, the blade back includes two main bodies and a dorsal fin located between the two main bodies, one end of the two main bodies is respectively connected to the opposite ends of the blade surface, the dorsal fin includes an ascending section and a descending section connected in sequence along the blade width direction, one end of the ascending section away from the descending section and one end of the descending section away from the ascending section are respectively connected to the other end of the two main bodies to form a dolphin-shaped airfoil structure.

2. The blade of the bionic propeller based on the dolphin dorsal fin shape according to claim 1, characterized in that: Assume a two-dimensional local coordinate system OXY of the blade section profile value point, wherein the origin O is the tangent point of the spiral line and the blade section, the blade width direction along the blade section is the OX axis, the direction perpendicular to the OX axis and pointing to the blade back or blade surface is the OY axis, the X coordinate value is expressed in % of the blade width, is the horizontal coordinate of the blade section profile value point, the vertical coordinate Y coordinate value is expressed in % of the maximum vertical distance between the main body and the blade surface, the vertical coordinate of the blade back is expressed as Y0, and the vertical coordinate of the blade surface is expressed as Y U ; The dorsal fin portion is formed in the range of X=30% to 40%, the rising section is in the range of X=30% to 34%, and the vertical coordinate Y0 of the back of the leaf of the rising section rises from 100% to 130% in the range of X=30% to 34%, the downward bending section is in the range of X=34% to 40%, and gradually bends downward from the range of X=34% to 40%, thereby forming a dolphin dorsal fin-shaped geometric mutation.

3. The blade of the bionic propeller based on the dolphin dorsal fin shape according to claim 2, characterized in that: In the range of X=30% to 40%, the surface slope of the dorsal fin portion changes as follows: In the interval X=30%→34%, the slope of the back surface of the ascending section is (130-100) / (34-30)=7.5, so that the back surface of the blade forms an upward deflection angle of arctan(7.5)≈82.4; In the range of X=34%→40%, the slope of the back surface of the downward curved section is (98.33-130) / (40-34)≈-5.278, so that the back surface of the blade forms a downward deflection angle of arctan(-5.278)≈-79.31°.

4. The blade of the bionic propeller based on the dolphin dorsal fin profile according to claim 3, characterized in that: The two-dimensional airfoil data of the blade section are shown in the following table:

5. The blade of the bionic propeller based on the dolphin dorsal fin profile according to claim 2, characterized in that: In the interval of X=30%→40%, the interpolation density of the two-dimensional local type value points of the leaf section is greater than the interpolation density of the two-dimensional local type value points in the interval of X=0-30% and the interval of X=40-100%.

6. A bionic propeller based on the blade section of a dolphin dorsal fin, characterized in that: The invention comprises a blade as described in any one of claims 1 to 5.

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