Catheter paddle with bionic leading edge nodule blade configuration and manufacturing method

Abstract

According to the ducted propeller with the bionic front edge nodule blade structure and the manufacturing method, starting from two-dimensional type value points of propeller blades, chord lengths of several groups of cross sections are changed by modifying two-dimensional type value points of related cross sections, and therefore the shape of the front edge of the blade is finally changed; the invention particularly provides the ducted propeller with the bionic front edge nodule blade configuration, which is obtained according to the manufacturing method of the ducted propeller with the bionic front edge nodule blade configuration. The technical problems existing in the aspects of shape design optimization, fluid performance optimization design and propeller noise control of a ducted propeller and a conventional propeller in the prior art are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of marine and ocean engineering propulsion systems. Specifically, it relates to a ducted propeller with a biomimetic leading-edge tubercle blade configuration and a manufacturing method therefor. Background Art

[0002] Ocean exploration and ocean resource development have been important goals of countries around the world since the 21st century. Due to the limited nature of land resources, the development, utilization, and protection of ocean resources are extremely urgent. In the development of ocean resources, propulsion devices are extremely necessary, and there is an increasing demand for their performance. Therefore, various special propellers have been developed.

[0003] The ducted propeller is one of the special propellers. It consists of a standard propeller and a duct with a two-dimensional hydrofoil cross-section. The propeller is fixed in the middle of the duct, and they together form the overall propulsion device. Since the duct has an obvious optimization effect on the propeller flow field, it can effectively improve the influence of the ship's wake on the performance of the ducted propeller; the duct can improve the propulsion parameters such as the thrust and torque of the propeller, and can provide additional thrust under heavy load and low speed conditions, thereby significantly improving the overall propulsion efficiency of the ducted propeller; the ducted propeller can adapt to working conditions with large loads and maintain excellent hydrodynamic performance under such conditions.

[0004] Therefore, the ducted propeller is widely used in the field of ship propulsion, especially as a propulsion device for heavy-duty ships. At the same time, in recent research, it has been found that when the ducted propeller is arranged on a heavy-duty ship, it is beneficial to reduce vibration, thereby helping to improve the noise performance to a certain extent. It is widely used in the field of ship propulsion, especially in low-speed heavy-duty ships.

[0005] In addition, in recent years, in the field of underwater unmanned vehicle propulsion, the ducted propeller has also been widely adopted. Therefore, the research demand for the ducted propeller is becoming increasingly obvious, and the ducted propeller propulsion technology has received extensive attention and in-depth research.

[0006] Most of the existing patents related to ducted propellers focus on the design of solid propellers or related additional structures such as motors and propellers. For the optimization of the shape of ducted propellers, most of them are reflected in the optimization of the duct. For example, in a ducted propeller applying a bionic duct in Patent Document CN106828849A, the surface of the duct is a periodic wavy structure composed of concave and convex protrusions, thereby achieving the optimization of the duct; Patent Document CN117429575A discloses a full-parameterized rim propeller design method, device and storage medium, which uses an appropriate airfoil parameterization method to describe the continuous and smooth airfoil geometric shape, constructs a blade airfoil section model and a rotor hub section model, and generates a blade airfoil surface model and a rotor hub model; connects the blade airfoil surface model with the rotor hub model to form a closed rotor model; establishes a duct model according to the characteristic parameters corresponding to the airfoil section models of the duct airfoil at different radial directions by using 3D modeling software; connects the duct model and the rotor model according to the relative distance between the rotor and the duct inlet to form a complete rim propeller model. However, the airfoil of the propeller blade in this technical solution is a common airfoil rather than a bionic airfoil, which may easily cause problems such as cavitation and high noise at high speeds; the fluid performance and propeller noise control are not good.

[0007] There are relatively many patents related to leading-edge nodules and bionic propeller shapes, but they mainly focus on the blade configurations of conventional hydrodynamic propellers, the blade configurations of aerodynamic propellers, etc.

[0008] The related prior arts are as follows:

[0009] (1) A novel bionic propeller (Patent Document CN113716004A), which discloses a novel bionic propeller. By attaching a bionic fin with a sinusoidal curve edge to the edge of the propeller blade, a bionic propeller is obtained.

[0010] (2) A bionic propeller for drag reduction and noise reduction and its preparation method (Patent Document CN113086169A), which discloses a bionic propeller for drag reduction and noise reduction and its preparation method. By cutting the model near the trailing edge of the fan blade, a blade trailing edge with a sinusoidal curve structure is obtained, and a basic shape of a bionic fan blade is obtained. Moreover, by adding a fiber structure to the blade surface, the drag of the blade is reduced.

[0011] (3) A ship bionic propeller (Patent Document CN203032905U), which discloses a ship bionic propeller, constructs a propeller with a continuous protruding node leading edge, and the protruding nodes are connected by a unilateral sinusoidal curve, increasing the disc area ratio of the blade.

[0012] (4) A bionic propeller (Patent Document CN104627341A), which discloses a bionic propeller. On the basis of the ship bionic propeller in Patent Document CN203032905U, a serrated tip structure is added to the tip of the propeller blade for noise reduction requirements;

[0013] (5) A bionic structure anti-scouring pile foundation (Patent Document CN211113709U), which discloses a bionic structure anti-scouring pile foundation. A leading edge protrusion is provided on the water-facing surface of the pile foundation body. The cross-sectional shape at the wave crest is the same as that at the wave trough of the leading edge protrusion and is the same as the cross-sectional shape of the pile foundation body, so as to change the stress of the pile foundation and the flow field distribution, reduce the submersible flow under the water-facing surface of the pile column, and reduce the scouring of the pile foundation.

[0014] However, most of the leading edge nodule configurations of these propeller types are obtained by only changing the leading edge line shape, cutting or adding to the leading edge of the propeller, so as to obtain a propeller type with a bionic leading edge nodule. It is difficult to ensure the precise connection of the leading edge and the overall blade profile of the propeller.

[0015] In view of the technical problems existing in the prior art, the present invention proposes a ducted propeller with a bionic leading edge nodule blade configuration and a manufacturing method, which solves the configuration and hydrodynamic performance problems existing in the existing ducted propellers. Summary of the Invention

[0016] Aiming at the defects in the prior art, the purpose of the present invention is to provide a ducted propeller with a bionic leading edge nodule blade configuration and a manufacturing method.

[0017] According to a manufacturing method of a ducted propeller with a bionic leading edge nodule blade configuration provided by the present invention, it includes:

[0018] Step S1: Determine the basic parameters of the propeller and obtain the initial two-dimensional value points of each section of the propeller blade;

[0019] Step S2: Change the two-dimensional value point coordinates. By modifying the two-dimensional value points of relevant cross-sections, change the chord lengths of several groups of cross-sections. The change of the chord length is carried out alternately, that is: the chord lengths of one group of cross-sections are increased, while those of the adjacent group are decreased;

[0020] Step S3: Calculate and obtain the three-dimensional coordinate points of each section of the blade;

[0021] Step S4: Create curves from the coordinate points to obtain the sectional lines of the propeller and the leading edge nodule leading edge line;

[0022] Step S5: Create a propeller surface using the curves obtained in Step S4 and create a propeller shaft to obtain a propeller with a bionic leading edge nodule configuration;

[0023] Step S6: Create a duct model based on the airfoil profile;

[0024] Step S7: Assemble the propeller obtained in Step S5 to be concentric with the duct. Thus, a ducted propeller model with a biomimetic leading-edge tubercle blade configuration is obtained, and a ducted propeller is manufactured based on the obtained ducted propeller model.

[0025] Preferably, Step S1 includes:

[0026] Determine the basic parameters of the propeller, such as diameter, number of blades, disk area ratio, and pitch; obtain the profile points of each section of its blades through the profile data of the propeller.

[0027] Preferably, Step S2 includes:

[0028] Step S21: Change the two-dimensional profile points at the sections of 0.2R, 0.4R, 0.6R, and 0.8R in the two-dimensional profile point coordinates; move all the profile points of the first half of the airfoil at the sections of 0.2R and 0.6R forward by a distance A = 0.1R, and move all the profile points of the first half of the airfoil at the sections of 0.4R and 0.8R backward by a distance A = 0.1R, so that the surface formed by the final overall profile is smooth;

[0029] x2 = x1 + 0.1R at the sections of y = 0.2R and 0.6R

[0030] x2 = x1 - 0.1R at the sections of y = 0.4R and 0.8R

[0031] where x2 is the modified profile point coordinate of the first half of the airfoil; x1 is the profile point coordinate of the first half of the airfoil before modification, A represents the amplitude of the leading-edge airfoil, and R represents the radius of the propeller, with the unit of m.

[0032] Preferably, Step S2 includes:

[0033] According to the conversion coordinate formula from the two-dimensional profile points of the propeller to the three-dimensional profile, convert the given two-dimensional profile points of the blade sections according to the following formula to obtain the three-dimensional coordinates of each section of the blade:

[0034] X = R i cos[(X2cosφ - Y2sinφ) / R i

[0035] Y = R i sin[(X2cosφ - Y2sinφ) / R i

[0036] Z = X2sinφ + Y2cosφ

[0037] ​​In the formula, X, Y, and Z are the three-dimensional coordinate values of the propeller profile points, X2 and Y2 are the two-dimensional coordinate point values of each section of the blade, φ is the pitch angle, and R i is the radius length of the blade section.

[0038] Preferably, the step S4 includes:

[0039] Step S41: Create three-dimensional curves for each section according to the obtained three-dimensional coordinate points, and then smoothly connect the control points at the leading edges of each section with a sine curve to form a biomimetic leading edge;

[0040] Step S42: According to the obtained three-dimensional coordinate points, the profile of the trailing edge remains unchanged, and directly connect the profile points at the trailing edges of each section into a smooth curve.

[0041] Preferably, the step S5 includes:

[0042] Step S51: Use the leading edge and trailing edge curves of step S4 as the modeling guide lines to connect the curves of each section, create a propeller surface, and close the surface at the tip of the blade to obtain a blade;

[0043] Step S52: Mirror the blade to obtain a total of four groups of blades;

[0044] Step S53: Create a propeller shaft and connect the blade to the propeller shaft to obtain a propeller with a biomimetic leading edge nodule configuration.

[0045] Preferably, the step S6 includes:

[0046] Rotate the two-dimensional profile of the duct around the axis of the propeller for one week to obtain a duct model; the length Ld of the duct is taken as the radius of the blade.

[0047] A ducted propeller with a biomimetic leading edge nodule blade configuration according to the present invention is obtained by the manufacturing method of the ducted propeller with a biomimetic leading edge nodule blade configuration according to the present invention.

[0048] An underwater vehicle according to the present invention employs the ducted propeller with a biomimetic leading edge nodule blade configuration provided by the present invention.

[0049] A ship according to the present invention employs the ducted propeller with a biomimetic leading edge nodule blade configuration provided by the present invention.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] 1. The present invention changes the chord lengths of several cross-sections by modifying the two-dimensional offset points of the relevant cross-sections, thereby ultimately changing the shape of the leading edge of the blade; it can ensure that the biomimetic leading edge configuration of the leading edge and the overall propeller are perfectly fitted, and has little influence on the hydrodynamic performance of the propeller.

[0052] 2. The present invention optimizes the shape design of the ducted propeller and the conventional propeller, and simultaneously achieves the technical effects of optimizing the fluid performance and controlling the propeller noise.

[0053] 3. The present invention starts from the two-dimensional offset points to change the propeller profile, rather than cutting or adding materials to the structure of the original conventional propeller, which ensures the modeling accuracy of the obtained propeller and the smoothness and consistency of the blade disk shape. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Other features, objects, and advantages of the present invention will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0055] Figure 1 Schematic diagram of the modified three-dimensional offset points and the biomimetic leading edge line type.

[0056] Figure 2 Schematic diagram of the propeller offset points and the sectional lines.

[0057] Figure 3 Schematic diagram of a single blade structure with a biomimetic leading edge nodule configuration.

[0058] Figure 4 Schematic diagram of a propeller structure with a biomimetic leading edge nodule configuration.

[0059] Figure 5 Schematic diagram of a ducted propeller with a biomimetic leading edge nodule configuration. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0060] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those of ordinary skill in the art can make several changes and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0061] The inventive concept of a ducted propeller with a biomimetic leading edge tubercle blade configuration and its manufacturing method provided by the present invention is as follows: Starting from the two-dimensional profile points of the propeller blade, by modifying the two-dimensional profile points of relevant cross-sections, the chord lengths of certain groups of cross-sections are changed. The changes in chord lengths are staggered, that is, the chord length of one group of cross-sections is increased, and the chord length of the adjacent group is decreased, and so on. After changing the profile points of these cross-sections, some control points on the leading edge of the ducted propeller blade are changed at this time. Connecting all the control points on the leading edge with a sine curve can obtain a leading edge with a leading edge tubercle, thereby finally changing the linear shape of the leading edge of the blade to obtain a biomimetic blade profile. The propeller profile with a biomimetic leading edge tubercle has a better optimization and improvement effect on the pulsating force amplitude of the ducted propeller blade and the stability of the wake behind the propeller, and can improve its noise performance.

[0062] The following is a specific description of the present invention.

[0063] As Figure 1 shown, the embodiment of the present invention provides a manufacturing method of a ducted propeller with a biomimetic leading edge tubercle blade configuration, including:

[0064] Step S1: Determine the basic parameters of the propeller and obtain the initial two-dimensional profile points of each section of the propeller blade; the step S1 includes: determining the basic parameters such as the diameter, number of blades, disk area ratio, pitch, etc. of the propeller; obtaining the profile points of each section of its blade through the profile data of the KA4-70 type propeller.

[0065] Step S2: Change the two-dimensional profile point coordinates. By modifying the two-dimensional profile points of relevant cross-sections, the chord lengths of certain groups of cross-sections are changed. The changes in chord lengths are carried out in a staggered manner, that is: the chord length of one group of cross-sections is increased, while the chord length of the adjacent group is decreased;

[0066] Step S3: Calculate and obtain the three-dimensional coordinate points of each section of the blade;

[0067] Step S4: Create curves from the coordinate points in the CATIA modeling software to obtain the profile lines of each section of the propeller and the leading edge line with a biomimetic leading edge tubercle;

[0068] Step S5: Create a propeller surface using the curves obtained in step S4 and create a propeller shaft to obtain a KA4-70 type propeller with a biomimetic leading edge tubercle configuration;

[0069] Step S6, create a duct model according to the airfoil profile;

[0070] Step S7, assemble the propeller obtained in step S5 to be concentric with the duct. Thus, a ducted propeller model with a biomimetic leading edge tubercle blade configuration is obtained, and a ducted propeller with a biomimetic leading edge tubercle blade configuration is manufactured according to the above ducted propeller model; As Figure 5 shown.

[0071] Further, the step S2 includes:

[0072] Step S21: Change the two-dimensional coordinate value points of the profiles at 0.2R, 0.4R, 0.6R, and 0.8R in the two-dimensional value points; move all the coordinate value points of the front half of the airfoil at the profiles at 0.2R and 0.6R forward by a distance A = 0.1R, and move all the coordinate value points of the front half of the airfoil at the profiles at 0.4R and 0.8R backward by a distance A = 0.1R, so that the surface formed by the final overall profile line is smooth;

[0073] x2 = x1 + 0.1R for profiles at y = 0.2R and 0.6R

[0074] x2 = x1 - 0.1R for profiles at y = 0.4R and 0.8R

[0075] Wherein, x2 is the coordinate value point of the front half of the modified airfoil; x1 is the coordinate value point of the front half of the airfoil before modification, A represents the amplitude of the leading-edge airfoil, and R represents the radius of the propeller, with the unit of m.

[0076] Further, as Figure 3 shown, the step S3 includes:

[0077] According to the conversion coordinate formula from the two-dimensional value points of the propeller to the three-dimensional profile line, convert the given two-dimensional value points of the blade profiles according to the following formula to obtain the three-dimensional coordinates of each blade profile:

[0078] X = R i cos[(X2cosφ - Y2sinφ) / R i

[0079] Y = R i sin[(X2cosφ - Y2sinφ) / R i

[0080] Z = X2sinφ + Y2cosφ

[0081] In the above formula, X, Y, and Z are the three-dimensional coordinate values of the propeller value points respectively, X2 and Y2 are the two-dimensional coordinate point values of each blade profile, φ is the pitch angle, and R i is the radius length of each blade profile.

[0082] Further, the step S4 includes: creating curves of the three-dimensional coordinate points obtained in the step S3 in the CATIA modeling software; specifically including:

[0083] Step S41: First, create the three-dimensional curves of each profile, and then smoothly connect the control points at the leading edge of each profile with a sine curve to form a biomimetic leading edge;​​

[0084] Step S42: Keep the profile of the trailing edge unchanged, and directly connect the trailing edge profile value points of each section into a smooth curve;

[0085] Further, the said Step S5 includes:

[0086] Step S51: Use the leading edge and trailing edge curves of Step S4 as the modeling guide lines, connect the curves of each section, create a propeller surface, and close the surface at the blade tip to obtain a blade;

[0087] Step S52: Mirror the blade to obtain a total of four groups of blades;

[0088] Step S53: Create a propeller shaft and make the blade connect to the propeller shaft to obtain a propeller with a biomimetic leading edge tubercle configuration;

[0089] Further, the said Step S6 includes:

[0090] Rotate the two-dimensional profile line of the duct around the axis of the propeller for one week to obtain a duct model; for accurate matching with the blade, the length of the duct is the same as the radius of the blade, denoted by Ld.

[0091] The manufacturing method of Step S2 of the present invention is an innovation compared with the methods in the prior art. Starting from two-dimensional profile value points to change the propeller profile, rather than cutting or adding materials on the structure of the original conventional propeller, it ensures the modeling accuracy of the obtained propeller and the smoothness and consistency of the blade disk shape.

[0092] Further, the present invention also provides a duct propeller model with a biomimetic leading edge tubercle blade configuration obtained according to the above-mentioned manufacturing method of a duct propeller with a biomimetic leading edge tubercle blade configuration.

[0093] Further, the present invention also provides a duct propeller with a biomimetic leading edge tubercle blade configuration obtained according to the above-mentioned duct propeller model with a biomimetic leading edge tubercle blade configuration; the duct propeller with a biomimetic leading edge tubercle blade configuration reduces the level of blade pulsating force and improves the noise reduction performance.

[0094] In summary, the present invention provides a duct propeller with a biomimetic leading edge tubercle blade configuration and a manufacturing method. The manufacturing method starts from the two-dimensional profile value points of the propeller blade, modifies the two-dimensional profile value points of relevant cross sections, changes the chord length of several groups of cross sections, and finally changes the shape of the blade leading edge. It solves the technical problems existing in the shape design optimization, fluid performance optimization design, and propeller noise control of duct propellers and conventional propellers in the prior art.

[0095] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0096] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for manufacturing a ducted propeller having a bionic leading edge tubercle blade configuration, characterized in that: include: Step S1: Determine the basic parameters of the propeller and obtain the initial two-dimensional value points of each section of the propeller blade; Step S2: changing the coordinates of the two-dimensional value points, and changing the chord lengths of certain groups of cross sections by modifying the two-dimensional value points of the relevant cross sections. The change of the chord length is performed in an interlaced manner, that is, one group of cross sections increases the chord length, while the adjacent group decreases the chord length; Step S3: Calculate and obtain the three-dimensional coordinate points of each section of the blade; Step S4: Create a curve from coordinate points to obtain various section lines of the propeller and bionic leading edge nodule guide lines; Step S5: using the curve obtained in step S4 to create a propeller surface, and creating a propeller shaft, to obtain a propeller with a bionic leading edge nodule configuration; Step S6: creating a duct model according to the airfoil profile; Step S7: Assemble the propeller obtained in step S5 to be concentric with the duct, thereby obtaining a ducted propeller model with a bionic leading edge nodule blade configuration, and manufacture the ducted propeller based on the obtained ducted propeller model.

2. The method for manufacturing a ducted propeller having a bionic leading edge tubercle blade configuration according to claim 1, characterized in that: The step S1 comprises: Determine the basic parameters of the propeller, such as the diameter, number of blades, disc ratio, and pitch; obtain the type value points of each section of the propeller blade through the propeller type value data.

3. The method for manufacturing a ducted propeller having a bionic leading edge tubercle blade configuration according to claim 1, characterized in that: The step S2 comprises: Step S21: changing the two-dimensional coordinate shape value points of the sections 0.2R, 0.4R, 0.6R, and 0.8R in the two-dimensional shape value point coordinates; moving the coordinates of all shape value points of the front half of the airfoil of the sections at 0.2R and 0.6R forward by a distance A=0.1R, and moving the coordinates of all shape value points of the front half of the airfoil of the sections at 0.4R and 0.8R backward by a distance A=0.1R, so that the curved surface formed by the final overall shape line is smooth; x2=x1+0.1R y=cross section at 0.2R and 0.6R x2=x1-0.1R y=cross section at 0.4R and 0.8R Among them, x2 is the coordinate of the value point of the front half of the airfoil after modification; x1 is the coordinate of the value point of the front half of the airfoil before modification, A represents the amplitude of the leading edge airfoil, and R represents the radius of the propeller, in m.

4. The method for manufacturing a ducted propeller having a bionic leading edge tubercle blade configuration according to claim 1, characterized in that: The step S2 comprises: According to the conversion coordinate formula of the propeller's two-dimensional shape value points to three-dimensional shape lines, the given two-dimensional shape value points of the blade section are converted according to the following formula to obtain the three-dimensional coordinates of each blade section: X=R i cos[(X2cosφ-Y2sinφ) / R i ] <h2 style=";text-align:left;direction:ltr">Y=R<h2 style=";text-align:left;direction:ltr"> i <h2 style=";text-align:left;direction:ltr"> sin[(X2cosφ-Y2sinφ) / R<h2 style=";text-align:left;direction:ltr"> i <h2 style=";text-align:left;direction:ltr"> ] Z=X2sinφ+Y2cosφ In the formula, X, Y, and Z are the three-dimensional coordinate values ​​of the propeller type point, X2 and Y2 are the two-dimensional coordinate values ​​of each section of the blade, φ is the pitch angle, and R i is the radius of the leaf section.

5. The method for manufacturing a ducted propeller having a bionic leading edge tubercle blade configuration according to claim 1, characterized in that: The step S4 comprises: Step S41: creating a three-dimensional curve of each section according to the obtained three-dimensional coordinate points, and then smoothly connecting the control points of the front edge of each section with a sine curve to form a bionic front edge; Step S42: Based on the obtained three-dimensional coordinate points, the profile of the trailing edge remains unchanged, and the profile points of the trailing edge of each section are directly connected into a smooth curve.

6. The method for manufacturing a ducted propeller with a bionic leading edge tubercle blade configuration according to claim 1, characterized in that: The step S5 comprises: Step S51: using the leading edge and trailing edge curves in step S4 as modeling guide lines, connecting the curves of each section to create a propeller surface, and closing the top of the blade to obtain a blade; Step S52: mirroring the blades to obtain a total of four groups of blades; Step S53: Create a propeller shaft and connect the propeller blades to the propeller shaft to obtain a propeller with a bionic leading edge nodule structure.

7. The method for manufacturing a ducted propeller having a bionic leading edge tubercle blade configuration according to claim 1, characterized in that: The step S6 comprises: The two-dimensional profile of the duct is rotated around the propeller axis to obtain the duct model; the length Ld of the duct is taken as the radius of the blade.

8. A ducted propeller with a bionic leading edge tubercle blade configuration, characterized in that: The method for manufacturing a ducted propeller with a bionic leading edge nodular blade configuration according to any one of claims 1 to 7 is obtained.

9. An underwater vehicle, characterized in that: A duct propeller with a bionic leading edge nodular blade configuration as described in claim 8 is used.

10. A ship, characterized in that: A duct propeller with a bionic leading edge nodular blade configuration as described in claim 8 is used.

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