High-efficiency low-noise bionic ring conduit propeller based on multi-biometric feature cooperation
By designing a biomimetic annular duct propulsion system, incorporating the biological characteristics of humpback whales, owls, and long-eared owls, and optimizing flow separation and noise, the system solves the problems of flow separation and noise radiation in traditional duct propellers at high speeds, achieving high-efficiency, low-noise ship propulsion and environmental friendliness.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HARBIN ENG UNIV
- Filing Date
- 2025-07-29
- Publication Date
- 2026-07-24
AI Technical Summary
Traditional ducted propellers suffer from problems such as large-scale flow separation in the wake field, a surge in turbulent kinetic energy peak, a decrease in local cavitation number, and noise radiation at high speeds or angles of attack, making it difficult to meet the requirements of high-precision operation scenarios.
The design employs a ring-shaped duct propeller, combined with the flow control mechanism of the humpback whale's forewing. Through a biomimetic ring-shaped duct propulsion system, a high-efficiency, low-noise biomimetic ring-shaped duct propulsion system with multiple biological features is constructed. The system includes a ring-shaped duct and a ring-shaped propeller assembly. The ring-shaped duct has a circular tube structure with two airfoil sections along its axial direction. The front end has a wave-shaped leading edge array, and the rear end has a regularly distributed serrated array. The ring-shaped propeller assembly is located inside the ring-shaped duct and includes a central shaft and multiple ring blades. The ring blades are open, rotating rings. The design incorporates biomimetic features such as the forewing of a humpback whale, the feather cleft of an owl, and the wing surface grooves of a long-eared owl, constructing a regional biomimetic duct structure.
It achieves flow separation and noise optimization, improves propulsion efficiency, reduces the energy density of the turbulent noise spectrum, increases the critical coefficient of cavitation, meets the EEDI energy efficiency index and DNV Silent-R level noise limit requirements, and provides a high-efficiency, low-noise green ship propulsion system.
Smart Images
Figure CN224546266U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of ship and marine underwater propulsion technology, specifically to a ring-shaped duct propeller duct structure based on the fusion design of multiple biomimetic structures. Background Technology
[0002] The field of marine and underwater propulsion technology currently faces severe technical challenges: While traditional ducted propellers achieve a 30-35% increase in static thrust coefficient and a 20% increase in critical cavitation coefficient at low speeds through ducted structures, large-scale flow separation in the wake field at high speeds or angles of attack leads to a 40-60% surge in peak turbulent kinetic energy and triggers a risk of synergistic cavitation erosion due to a reduction in local cavitation number. Traditional ducted structures also suffer from technical defects such as inflow distortion, severe wake vortex dissipation, and broadband noise radiation. Research by the International Centre for Marine Hydrodynamics shows that the tip vortex energy generated by their open blade tip structure accounts for 35% of the total turbulent kinetic energy, resulting in a 9-12% decrease in propulsion efficiency and a 25% increase in broadband noise and energy density, severely restricting the ability to meet EEDI energy efficiency indicators (≥4.0) and noise standards.
[0003] Although annular propeller technology forces vortices to disperse along the annular surface rather than concentrate at the tip by fusing the closed annular structure with the propeller tip, secondary flow interference problems still exist in dynamic flow fields, such as the forward shift of the boundary layer separation point and excessive surface pressure pulsation amplitude. In fluid-structure interaction vibration scenarios of equipment such as deep-sea mining vehicles and intelligent tugboats, the pressure pulsation amplitude of existing solutions is still more than 12 dB higher than the biomimetic design benchmark, making it difficult to meet the stringent requirements of high-precision operations. Utility Model Content
[0004] To address the shortcomings of the existing technologies, the present invention aims to propose a high-efficiency, low-noise biomimetic annular duct propulsion device based on the synergy of multiple biological features. This device aims to solve the technical defects of traditional duct structures, such as inflow distortion, severe tail vortex dissipation, and broadband noise radiation, as well as secondary flow interference problems such as the forward shift of the propeller boundary layer separation point and the excessive amplitude of surface pressure pulsation.
[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:
[0006] A high-efficiency, low-noise biomimetic annular duct propulsion device based on the synergy of multiple biological features includes an annular duct and an annular propeller assembly. The annular duct adopts a circular tube structure, and the cross-section of the annular duct along its axial direction is two airfoil sections.
[0007] The annular conduit has a wavy leading edge array at the front end and a regularly distributed serrated array at the rear end. The number of wavy protrusions is equal to the number of serrations, and they correspond one-to-one.
[0008] The annular propeller assembly is located inside the annular duct and includes a central shaft and multiple annular blades. The central shaft is coaxially arranged with respect to the annular duct, and all the annular blades are located on the outer circumferential wall of the central shaft.
[0009] The annular conduit has multiple corrugated grooves continuously distributed along its circumference on its outer wall, each corrugated groove extending along the axial direction of the annular conduit to its front and rear ends.
[0010] Furthermore, the outer circumferential wall of the annular conduit is a conical shape with a flared front end and a constricted rear end.
[0011] The wavy protrusions are isosceles triangular structures, and all the wavy protrusions are evenly distributed in a circular manner at the front end of the annular conduit. Each wavy protrusion is an integral structure with the main body of the annular conduit.
[0012] Furthermore, the top of the wavy protrusion has a rounded corner structure, and the adjacent side roots of any two adjacent wavy protrusions are smoothly transitioned with rounded corners.
[0013] The outer surface of the wavy protrusion is consistent with the outer circumference of the annular conduit. The thickness of the wavy protrusion decreases sequentially from its rear to the two side edges and the top. The adjacent sides of two wavy protrusions form a flow guide groove located on the inner wall of the annular conduit.
[0014] Furthermore, the sawtooth array includes multiple triangular sawtooths, all of which are distributed adjacently in a circular manner at the rear end of the annular conduit and are integral with the main body of the annular conduit.
[0015] The tips of the triangular serrations are rounded, and the roots of any two adjacent triangular serrations are smoothly transitioned with rounded corners.
[0016] Furthermore, the annular blade is an open, rotating ring, and there are four annular blades, which are evenly distributed on a circumference with the central axis as the center.
[0017] The two ends of each annular blade are staggered and arranged one in front of the other along the axial direction of the central axis, and are fixedly connected to the outer wall of the central axis.
[0018] Furthermore, the wave groove is located between the tips of two adjacent saw teeth and the tops of two wave-shaped protrusions corresponding to the two saw teeth respectively.
[0019] The troughs of the wave groove correspond to the root positions of two adjacent saw teeth and the connection points of two adjacent wave-shaped protrusions, while the crests of the wave groove correspond to the tips of the saw teeth and the tops of the wave-shaped protrusions corresponding to those saw teeth.
[0020] By adopting the above technical solution, the beneficial technical effects of this utility model are as follows: This utility model innovatively integrates three types of biomimetic features: humpback whale forefin nodules, owl feather splits, and long-eared owl wing surface grooves, to construct a regional biomimetic duct structure: the leading edge wave protrusion array is based on the humpback whale fluid regulation mechanism, the trailing edge asymmetric sawtooth unit imitates the owl vortex core dissipation characteristics, and the outer wall microgroove system reproduces the long-eared owl turbulence suppression mechanism, achieving optimization of flow separation, cavitation erosion, and noise; combined with the closed flow channel design of the annular propeller, it further reduces the tip vortex energy loss of traditional propellers, improves the peak propulsion efficiency, reduces the inflow velocity non-uniformity, reduces the energy density of the turbulence noise spectrum, and increases the critical coefficient of cavitation erosion, meeting the EEDI energy efficiency index (≥4.0) and DNV Silent-R level noise limit requirements, providing an innovative solution for green ship propulsion systems that combines high efficiency and environmental friendliness. Attached Figure Description
[0021] Figure 1 This is a three-dimensional schematic diagram of the efficient and low-noise biomimetic annular duct propulsion device based on the synergy of multiple biological features of this utility model.
[0022] Figure 2 This is a rear view of the high-efficiency, low-noise biomimetic annular duct propulsion device based on the synergy of multiple biological features of this utility model.
[0023] Figure 3 This is a side view of the high-efficiency, low-noise biomimetic annular duct propulsion device based on the synergy of multiple biological features of this invention.
[0024] Figure 4 yes Figure 3 A cross-sectional view of the AA-shaped utility model.
[0025] Figure 5 This is a three-dimensional structural diagram of the annular propeller assembly of this utility model. Detailed Implementation
[0026] The present invention will now be described in detail with reference to the accompanying drawings:
[0027] This invention combines a duct and a ring-shaped propeller, leveraging the strengths of both, and constructs a duct structure with various biomimetic features. Through biomimetic design, it achieves flow field reconstruction and energy dissipation control of the propulsion system, significantly improving propulsion efficiency and reducing underwater noise. Figures 1 to 5 A high-efficiency, low-noise biomimetic annular duct propulsion device based on the synergy of multiple biological features includes an annular duct 1 and an annular propeller assembly 2. The annular duct 1 adopts a circular tube structure, and the outer circumferential wall of the annular duct 1 is a conical shape with a flared front end and a constricted rear end. The cross-section of the annular duct 1 along its axial direction has two airfoil sections 14.
[0028] The annular duct 1 has a wavy leading edge array at its front end, which is a ring array structure formed by 18 wavy protrusions arranged sequentially adjacent to each other. Each wavy protrusion 11 is an isosceles triangle, with the angle between its two isosceles sides forming its apex. The side of each wavy protrusion 11 opposite its apex is fixedly connected to the front end face of the main body of the annular duct 1, forming an integral structure. The wavy protrusion 11 is based on the biomechanical model of the pectoral fin nodules of a humpback whale. By mimicking the pectoral fin nodules, the wavy protrusion 11 alters the thickness of the boundary layer, improving its structure and achieving drag reduction. This is used to induce microscale flow-oriented vortices to reduce inflow velocity non-uniformity and enhance momentum exchange between the inside and outside of the boundary layer.
[0029] Applying the front fin nodule of a humpback whale to the leading edge of the annular duct 1 results in greater power and less drag. In principle, the biomimetic nodule generates a pair of opposing vortices on both sides. These vortices bring the fluid closer to the airfoil surface, reducing flow separation and allowing the fin to maintain stable lift at larger angles of attack, with smoother stall characteristics. Experiments show that the lift coefficient of the biomimetic fin is higher and the drag is lower than that of a smooth fin; the discretized vortex shedding process at the leading edge reduces turbulence intensity, and the resulting low-pressure zone reduces surface friction drag; the biomimetic nodule can alter the boundary layer thickness, improving the boundary layer structure to achieve drag reduction and enhancing momentum exchange between the inside and outside of the boundary layer.
[0030] Specifically, all the wavy protrusions 11 are evenly distributed in a circular pattern at the front end of the annular conduit 1, and each wavy protrusion is an integral structure with the main body of the annular conduit 1. The top of the wavy protrusion 11 is rounded, and the adjacent side roots of any two adjacent wavy protrusions 11 are smoothly transitioned with rounded corners, so that the front end of the annular conduit 1 has a regular and continuous wavy structure along the circumferential direction.
[0031] The outer surface of the wavy protrusion 11 is consistent with the circumferential outer wall of the main body of the annular conduit 1. The thickness of the wavy protrusion 11 decreases sequentially from its rear to the side edges and top. The inner surface of the wavy protrusion 11 is smooth and consistent with the inner wall of the main body of the annular conduit 1. In addition, a flow guide groove 12 is formed on the adjacent sides of two wavy protrusions 11, located on the inner wall of the annular conduit 1. The flow guide groove 12 corresponds to the trough position of the wavy leading edge array at the front end of the annular conduit 1.
[0032] The rear end of the annular duct 1 features a regularly distributed serrated array, comprising 18 triangular serrations 13. More specifically, each of the 18 triangular serrations 13 is an isosceles triangle, arranged circumferentially adjacent to the rear end of the annular duct 1, and is an integral part of the main body of the annular duct 1. The tips of the triangular serrations 13 are rounded, and the roots of any two adjacent triangular serrations 13 are smoothly transitioned with rounded corners. The number of wave-shaped protrusions 11 is equal to the number of serrations, and they correspond one-to-one. The serrated array is located at the outlet end of the annular duct 1, designed in a biomimetic owl feather splitting configuration. This design divides the trailing vortices into small-scale vortices, reducing vortex-related energy concentration, and generates upward jets at the tooth roots to stabilize the boundary layer flow, thus segmenting the tail vortex and reducing turbulence noise.
[0033] The tail end of the annular duct 1 is biomimetic to the wing of an owl. The sound produced by an owl when flying is negligible. Research has found that the main reason for the owl's quiet flight is the serrated structure with concave and convex edges on the trailing edge of the wing. The serrated structure divides the vortices that fall off the trailing edge into small-scale vortices, reducing the energy concentration of vortex correlation, thereby suppressing broadband noise. An upward jet is generated at the root of the serrations, interfering with boundary layer separation and making the flow more stable. The concave and convex structure applied to the exhaust nozzle of an aircraft engine also effectively reduces noise.
[0034] The annular propeller assembly 2 is located inside the annular duct 1. It includes a central shaft 21 and four annular blades 22. The central shaft 21 is coaxially arranged with respect to the annular duct 1, and all the annular blades 22 are disposed on the outer circumference of the central shaft 21. The annular blades 22 are rotating rings with one side open, and the four annular blades 22 are evenly distributed on a circle with the axis of the central shaft 21 as the center.
[0035] Each of the annular blades 22 has its two ends staggered along the axial direction of the central axis 21, and is fixedly connected to the outer wall of the central axis 21. A closed flow channel is formed on the inner side of each annular blade 22. The gap between the side of the annular blade 22 away from the central axis 21 and the inner wall of the annular guide tube 1 is no greater than 0.05D, where D is the outer diameter of the middle part of the annular blade 22. The closed flow channel on the inner side of the annular blade 22 can synergistically suppress tip vortex generation. The closed flow channel design of each annular blade 22 in the annular propeller assembly, combined with the triple biomimetic structure of the annular guide tube 1, reduces tip vortex energy dissipation by 35%, decreases broadband noise spectrum energy density by 30%, and increases the cavitation erosion critical coefficient by 25%.
[0036] The annular conduit 1 has a plurality of wavy grooves 3 continuously distributed along its circumference on its outer wall. Each wavy groove 3 extends along the axial direction of the annular conduit 1 to its front and rear ends. The wavy groove 3 is located between the tips of two adjacent triangular serrations 13 and the tops of two wavy protrusions 11 corresponding to the two triangular serrations 13, respectively.
[0037] The troughs of the wave groove 3 correspond to the root positions of two adjacent triangular saw teeth 13 and the connection points of two adjacent wave-shaped protrusions 11. The crests of the wave groove 3 correspond to the tips of the triangular saw teeth 13 and the tops of the wave-shaped protrusions 11 corresponding to those triangular saw teeth 13. The continuous wave groove array on the outer circumference of the annular duct 1 is designed with a groove configuration similar to the wing surface of a long-eared owl. The wave groove 3 extends along the axial direction of the annular duct 1 and generates reverse secondary flow vortices to guide the longitudinal secondary flow and suppress transverse turbulent pulsations, thereby reducing the wall friction drag coefficient by ≥15%.
[0038] In principle, the radial grooves on the wing surface can effectively guide airflow to form longitudinal secondary airflow, reduce lateral turbulence pulsation, and play a certain guiding role; the serrated structure will divide the fluid into very small micro-airflows during flight, greatly reducing noise during flight.
[0039] The parts not mentioned in this utility model can be achieved by adopting or referencing existing technologies.
[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0041] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0042] Of course, the above description is not intended to limit the present utility model, and the present utility model is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present utility model should also fall within the protection scope of the present utility model.
Claims
1. A high-efficiency, low-noise biomimetic annular duct propulsion device based on the synergy of multiple biological features, characterized in that, It includes an annular duct and an annular propeller assembly. The annular duct adopts a circular tube structure, and the cross-section of the annular duct along its axial direction is two airfoil sections. The front end of the annular catheter has a wavy leading edge array, which is a ring array structure formed by 18 wavy protrusions arranged sequentially and adjacently. The rear end of the annular catheter has a regularly distributed serrated array. The number of wavy protrusions is equal to the number of serrations, and they correspond one-to-one. The annular propeller assembly is located inside the annular duct and includes a central shaft and multiple annular blades. The central shaft is arranged coaxially with the annular duct, and all the annular blades are located on the outer circumferential wall of the central shaft. The annular conduit has multiple corrugated grooves continuously distributed along its circumference on its outer wall, each corrugated groove extending along the axial direction of the annular conduit to its front and rear ends.
2. The high-efficiency, low-noise biomimetic annular duct propulsion device based on multi-biological feature synergy according to claim 1, characterized in that, The outer circumferential wall of the annular conduit is a conical shape with a flared front end and a constricted rear end. The wavy protrusions are isosceles triangular structures, and all the wavy protrusions are evenly distributed in a circular manner at the front end of the annular conduit. Each wavy protrusion is an integral structure with the main body of the annular conduit.
3. The high-efficiency, low-noise biomimetic annular duct propulsion device based on multi-biological feature synergy according to claim 2, characterized in that, The top of the wavy protrusion has a rounded corner structure, and the adjacent side roots of any two adjacent wavy protrusions are smoothly transitioned with rounded corners. The outer surface of the wavy protrusion is consistent with the outer circumference of the annular conduit. The thickness of the wavy protrusion decreases sequentially from its rear to the two side edges and the top. The adjacent sides of two wavy protrusions form a flow guide groove located on the inner wall of the annular conduit.
4. The high-efficiency, low-noise biomimetic annular duct propulsion device based on multi-biological feature synergy according to claim 1, characterized in that, The sawtooth array includes multiple triangular sawtooths, all of which are distributed adjacently in a circular manner at the rear end of the annular conduit and are integral with the main body of the annular conduit. The tips of the triangular serrations are rounded, and the roots of any two adjacent triangular serrations are smoothly transitioned with rounded corners.
5. The high-efficiency, low-noise biomimetic annular duct propulsion device based on multi-biological feature synergy according to claim 1, characterized in that, The annular blade is an open, rotating ring, and there are four annular blades, which are evenly distributed on a circumference with the central axis as the center. The two ends of each annular blade are staggered and arranged one in front of the other along the axial direction of the central axis, and are fixedly connected to the outer wall of the central axis.
6. The high-efficiency, low-noise biomimetic annular duct propulsion device based on multi-biological feature synergy according to claim 3, characterized in that, The wave groove is located between the tips of two adjacent saw teeth and the tops of two wave-shaped protrusions corresponding to the two saw teeth respectively. The troughs of the wave groove correspond to the root positions of two adjacent saw teeth and the connection points of two adjacent wave-shaped protrusions, while the crests of the wave groove correspond to the tips of the saw teeth and the tops of the wave-shaped protrusions corresponding to those saw teeth.