CN211364897U

CN211364897U - Bionic propeller with appearance of flagfish and characteristics of owl feather

Info

Publication number: CN211364897U
Application number: CN201921581750.7U
Authority: CN
Inventors: 邢普; 张绪坤; 魏晨宇; 吴晖
Original assignee: Nanchang Hangkong University
Current assignee: Nanchang Hangkong University
Priority date: 2019-09-23
Filing date: 2019-09-23
Publication date: 2020-08-28
Anticipated expiration: 2029-09-23

Abstract

The utility model discloses a bionical screw with flagfish appearance and owl feather characteristic in marine screw engineering field, this kind of screw is including the screw axle center of connecting the output shaft and the paddle that sets up around axle center circumference, its characterized in that: the shape of the paddle is the same as the contour of a sailfish, grooves are formed in the surface of the paddle, the grooves are arranged at equal intervals from a starting point to the trailing edge of the paddle along the large thickness line of the paddle, and the shape of each groove is the same as a concave portion formed between two adjacent main feathers on the lower surface of the owl wing. The friction resistance characteristic of the propeller blade changed by the technical scheme is more in line with fluid dynamics, so that water flow is guided along the streamline structure of the blade surface and the grooves, the resistance is reduced, and the vibration is reduced.

Description

Bionic propeller with appearance of flagfish and characteristics of owl feather

Technical Field

The utility model belongs to marine screw engineering field specifically is a bionic screw with flagfish appearance and owl feather characteristic.

Background

Owl has the unique ability to fly quietly. Even under the night sky background sound field with quiet sound, the noise of the owl in high-speed flight is difficult to be perceived by the prey. The silent flight characteristic of the owl is the overall effect comprehensively generated by a plurality of noise reduction factors of the microstructure characteristic of the body surface feather of the owl, the microstructure characteristic of the body surface skin and subcutaneous structure and the sound absorption characteristic of the owl. The main feathers of the owl wing are tightly covered and arranged in order, a structure similar to a groove is formed between two adjacent main feathers on the lower surface of the wing, and the feathers on the tail edge of the lower surface are arranged to be similar to a wave broken line shape when viewed from the cross section. This feature of the lower surface of the owl wing contributes greatly to its excellent flight ability.

The non-uniform flow field of the ship propeller causes the ship propeller to generate phenomena such as cavitation, vibration, noise, denudation and the like, which is an important subject of optimization research of the propeller performance. Therefore, the requirements of the propeller in the aspects of open water performance, cavitation performance, vibration noise and the like are considered in the design process of the propeller, and the requirements become important targets of the design research of the propeller. Besides, the propeller noise is one of the main noise sources of the ship, and the propeller with excellent hydrodynamic performance and small vibration noise is designed, so that the propeller has important practical application value.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem, the utility model discloses a through bionics design a section hydrodynamic force excellent performance, the little screw of vibration noise.

In order to achieve the above purpose, the technical solution of the present invention is as follows: the utility model provides a bionical screw with flagfish appearance and owl feather characteristic, is including the screw axle center of connecting the output shaft and the paddle that sets up around axle center circumference, the appearance of paddle is the same with the profile of flagfish, and the paddle surface is established flutedly, and the recess is arranged for starting point to paddle edge following department equidistant along the big thickness line of paddle, and the shape of recess is the same with the cove that forms between two adjacent main feathers of owl wing lower surface.

Further, the thickness of the section of the blade is gradually reduced from the blade root to the blade, the maximum thickness position of the section of the blade tends to the guide edge, and the camber of the blade surface is gradually reduced from the two sides of the guide edge and the trailing edge to the maximum thickness line.

Furthermore, the depth of the groove from the maximum thickness line to the trailing edge gradually becomes deeper, the deepest part of the groove is H1 which is 0.1H, H is the maximum thickness of the blade on the current arc surface, the maximum radius of the blade is R which is 13R, the transition section of the whole propeller is arranged from the blade root (3R) to the blade root (4R), and the width of the groove is 0.4R-0.7R.

Furthermore, the leading edge part of the blade adopts a protruding structure similar to the front end of the fish mouth of a flag, the height of the protruding structure is H2 which is 0.2H-0.4H, the width of the protruding structure is L which is 0.1L-0.3L, and L is the maximum width of the blade on the current arc surface.

Further, the grooves are arranged at equal intervals at 6R to 11R of the blade surface.

Further, the sectional shape of the groove is a curve y ═ a | sinx |, which is similar to a sine function, centered at the deepest part of the groove.

Further, a plurality of blades are arranged at the axis of the propeller, and the blades are arranged into equidistant circular matrixes along the axis of the propeller on the basis of the central axis of the propeller.

After the scheme is adopted, the following beneficial effects are realized: 1. compared with a propeller adopting a conventional structure, the technical scheme adopts a bionic structure, the friction resistance characteristic of the propeller blade is changed, the hydrodynamic is better met, and water flow is guided along a streamline structure of a paddle surface and a groove, so that the resistance is reduced, and the vibration is reduced.

2. The structure is designed through the fish mouth of the flag fish, so that the efficiency of the wing profile can be effectively improved, the flow induced vibration is reduced, and in addition, the tonal noise can be inhibited.

3. The radial flow of the water flow on the upper surface of the blade of the paddle is blocked to a certain extent by the groove structure at the lower end of the feather wing of the owl, and the surface groove structure can generate an accelerating effect on the water flow flowing through the tail edge of the paddle, so that the flow velocity of the water flow above the paddle is greater than that of the original paddle.

4. The contour structure of the paddle imitates the cross-sectional structure of the flagfish body, and the streamline surface can well reduce the resistance of water.

5. The front end of the guide edge can divide the water flow twice, so that the resistance is reduced. The groove structure on the upper surface weakens the mutual interference between water flows at the tail edge of the blade, improves the tail turbulence, and hinders the formation of large vortex at the tail part of the blade, thereby reducing the noise of the blade. And the protruding structure at the position of the guide edge and the small camber blade surface behind the guide edge are beneficial to the blade to adapt to the change of the attack angle in the hydrodynamic force, and the airfoil profile can effectively control and inhibit the unstable phenomenon of cavitation.

Drawings

FIG. 1 is a block diagram of an embodiment of the present invention;

FIG. 2 is a cross-sectional view of FIG. 1;

fig. 3 is an enlarged view of the groove of fig. 1.

Detailed Description

The following is further detailed by way of specific embodiments:

reference numerals in the drawings of the specification include: the propeller comprises a propeller axis 1, blades 2, a groove 3, a protruding structure 4 and a maximum thickness line 5.

The embodiment is basically as shown in the attached figure 1: a bionic propeller with the characteristics of a swordfish shape and the feathers of a owl comprises a propeller axis 1 connected with an output shaft and paddles 2 arranged circumferentially around the axis, firstly, the streamline proportion of the paddles 2 is designed according to the proportion of a spine-shaped structure part at the front end of the swordfish and the body of the swordfish, the shape of the paddles 2 is the same as the outline of the swordfish, grooves 3 are arranged on the surface of the paddles 2, the grooves 3 are arranged at equal intervals from a starting point to the positions along the edges of the paddles 2 along the large thickness line of the paddles 2, and the shape of the grooves 3 is the same as the concave position formed between two adjacent main feathers on the lower surface of the wing of.

Referring to fig. 2, the thickness of the cross section of the blade 2 gradually decreases from the blade root to the blade tip, the maximum thickness position of the cross section of the blade 2 tends to the leading edge, and the camber of the blade surface gradually decreases from the two sides of the leading edge and the trailing edge to the maximum thickness line.

Secondly, the requirement of the grooves 3 is adjusted according to the use requirement, and the distribution quantity of the grooves 3 is adjusted under the condition of meeting the rigidity requirement; the grooves 3 are arranged on the surfaces of the blades 2 at equal intervals from 6R to 11R, the cross section of each groove 3 is in a shape similar to a curve y of a sine function with the deepest part of each groove 3 as the center, a plurality of blades 2 are arranged on the propeller shaft center 1, and the blades 2 are arranged into an equally-spaced circular matrix along the propeller shaft center 1 on the basis of the central axis of the propeller shaft center 1.

Referring to fig. 3, again, the length and height of the protrusion at the leading edge of the blade 2 are adjusted; the depth of the groove 3 from the maximum thickness line to the trailing edge gradually becomes deep, the deepest part of the groove 3 is H1 which is 0.1H, H is the maximum thickness of the blade 2 on the current circular arc surface, the maximum radius of the blade 2 is R which is 13R, the transition section of the whole propeller is formed from the blade root (3R) to the blade root 4R, and the width of the groove 3 is 0.6R.

The leading edge part of the blade 2 adopts a protruding structure 4 similar to the front end of a flag fishmouth, the height H2 of the protruding structure 4 is 0.3H, the width L is 0.2L, and L is the maximum width of the blade 2 on the current circular arc surface.

Finally, the thickness of the blade 2 is designed, and the thickness t (at the section of 0.25r and 0.6 r) of the propeller blade 2 is not less than the value calculated according to the following formula:

trial Y- -power factor

K- -coefficient of material

X- -coefficient of rotation

Coefficient of power

In the formula

D- -diameter of propeller

P- -Pitch at calculated tangent plane

P_0.7A pitch at a cut of-0.7 r

r- -radius of propeller

K₁，K₂，K₃，K₄Coefficient of

N_e- -rated power of the host

Z- - -number of blades

b- -chord length of tangent plane at calculated radius

n_e- -rotational speed of the main propeller unit at nominal power

Coefficient of rotation

In the formula

-blade back rake angle

K₅，K₆，K₇，K₈Coefficient of

G- -density of blade Material

A_d-disc ratio of propeller

The material coefficient K.

The above description is only an example of the present invention, and the common general knowledge of the known specific structures and characteristics of the embodiments is not described herein. It should be noted that, for those skilled in the art, without departing from the structure of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.

Claims

1. The utility model provides a bionical screw with flag fish appearance and owl feather characteristic, includes the screw axle center of connecting the output shaft and the paddle that sets up around axle center circumference, its characterized in that: the shape of the paddle is the same as the contour of a sailfish, grooves are formed in the surface of the paddle, the grooves are arranged at equal intervals from a starting point to the trailing edge of the paddle along the large thickness line of the paddle, and the shape of each groove is the same as a concave portion formed between two adjacent main feathers on the lower surface of the owl wing.

2. The biomimetic propeller of claim 1, having a characteristic of a swordfish shape and owl feathers, wherein: the section thickness of the blade is gradually reduced from the blade root to the blade tip, the maximum thickness position of the section of the blade tends to the guide edge, and the camber of the blade surface is gradually reduced from the two sides of the guide edge and the trailing edge to the maximum thickness line.

3. The biomimetic propeller of claim 2, having a characteristic of a swordfish shape and owl feathers, wherein: the depth of the groove from the maximum thickness line to the trailing edge gradually becomes deeper, the deepest part of the groove is H1 which is 0.1H, H is the maximum thickness of the blade on the current circular arc surface, the maximum radius of the blade is R which is 13R, the transition section of the whole propeller is arranged from the blade root (3R) to the blade root (4R), and the width of the groove is 0.4R-0.7R.

4. The biomimetic propeller of claim 3, having a characteristic of a swordfish shape and owl feathers, wherein: the leading edge part of the blade adopts a protruding structure similar to the front end of a flag fishmouth, the height of the protruding structure is H2 which is 0.2H-0.4H, the width of the protruding structure is L which is 0.1L-0.3L, and L is the maximum width of the blade on the current arc surface.

5. The biomimetic propeller of claim 3, having a characteristic of a swordfish shape and owl feathers, wherein: the grooves are arranged at equal intervals from 6R to 11R on the blade surface.

6. The biomimetic propeller of claim 5, having a characteristic of a swordfish shape and owl feathers, wherein: the sectional shape of the groove is a curve y ═ a | sinx |, which is similar to a sine function, centered at the deepest part of the groove.

7. The biomimetic propeller of claim 6, having a characteristic of a swordfish shape and owl feathers, wherein: the propeller shaft center department is equipped with a plurality of paddles, and the paddle uses the axis in propeller shaft center as the basis to arrange the circular matrix of equidistant along the propeller shaft center.