A design method of complex curved surface space cooling channel based on cobweb bionics structure

Abstract

The application discloses a complex curved surface space cooling channel design method based on a spider web bionic structure. The method is based on the characteristics of the complex curved surface space structure, extracts the main geometric features of the spider web bionic structure, and is supplemented by three-dimensional curved surface structure topological mapping technology to realize the design of the cooling channel inside the curved surface space. The simulation test verification of the method shows that the overall flow field distribution is uniform, the heat exchange performance is excellent, and the flow resistance characteristic is low, and the method can provide cooling design support for high heat flux and high heat load components.

Description

Technical Field

[0001] This invention relates to a design method for complex curved surface space cooling channels based on a spider web biomimetic structure, belonging to the fields of heat transfer in energy, power, aviation, and aerospace. Background Technology

[0002] In aerospace and other fields, with the development of science and technology, the cooling problem under high heat flux density has become increasingly prominent. For example, high-speed aircraft are subject to aerodynamic heating, and the temperature far exceeds the tolerance temperature of the materials. High temperatures reduce the strength limit of the materials, thereby reducing the load-bearing capacity of the structure and causing thermal deformation. The electronic components inside the aircraft will also be affected accordingly, causing the entire aircraft to malfunction.

[0003] Channel cooling is a common method for solving such problems. By arranging cooling channels inside the structure, the physical or chemical heat sinks of the cooling medium within the channels absorb heat from the structural surface. A well-designed scheme can cool the structure to a lower temperature range, meeting the requirements for normal operation in high-temperature environments. Microchannel cooling technology, characterized by high heat dissipation efficiency and compact structure, has developed rapidly in recent years and has become an important technology for heat dissipation in high heat flux density electronic devices and microelectromechanical systems. Research shows that the cooling capacity of microchannels is closely related to the channel topology; topology optimization can further enhance the heat transfer performance of microchannels.

[0004] Traditional straight microchannels have a rectangular cross-section, which is simple, compact, and the most commonly used structural form. The flow field distribution within a straight microchannel reveals that the streamlines are almost all straight. Due to the thickening of the boundary layer, the fluid temperature gradually increases along the flow direction, leading to a continuous deterioration of the microchannel wall temperature. Therefore, optimizing the microchannel structure is an important research direction for enhancing microchannel heat transfer. The focus of channel cooling technology lies in the arrangement and parameter design of the cooling channels. Based on the actual structural form, while meeting cooling requirements, parameters such as coolant consumption, coolant pressure drop, and cooling efficiency are comprehensively considered. Compared with traditional parallel micropipes, biomimetic microchannel heat exchangers can achieve lower flow losses and more uniform temperature distribution while ensuring heat transfer efficiency. Current research focuses on studying the heat dissipation mechanism of cooling channels on simple planar structures; however, how to arrange cooling channels in complex curved surfaces is a key issue for realizing the application of biomimetic cooling channels. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a design scheme for a complex curved surface space cooling channel based on a spiderweb-inspired bionic structure. This scheme extracts the main geometric parameters of the spiderweb-inspired structure based on the characteristics of the complex curved surface space structure, and uses three-dimensional curved surface topology mapping technology to realize the design of the internal cooling channel in the curved space. This scheme exhibits uniform flow distribution, low flow resistance along the path, and excellent heat transfer performance.

[0006] The technical solution adopted in this invention is as follows:

[0007] A design method for cooling channels in complex curved surfaces based on a spider web biomimetic structure is proposed. This method designs a spider web biomimetic structure based on the characteristics of complex curved surface structures, extracts the main geometric structural parameters of the spider web biomimetic structure, and uses three-dimensional curved surface topology mapping technology to realize the design scheme of cooling channels inside the curved surface space.

[0008] The complex curved surface spatial structure features refer to the surface shape of the three-dimensional curved surface, the distribution of thermal load on the surface, and the location of the inlet and outlet of the cooling medium.

[0009] The aforementioned spiderweb-like biomimetic structure refers to a spiderweb-shaped cooling channel structure unit based on biomimetic principles. It includes hexagonal and L-shaped channel units, and combines multiple fractal channel units based on fractal theory to form a complex channel that first disperses and then converges. Furthermore, based on the surface shape and curvature distribution of the three-dimensional surface, hexagonal channel units are arranged in areas with high heat load (above 60% of peak heat load), while L-shaped channel units are used in areas with low heat load (below 40% of peak heat load) to match the overall channel inlet and outlet design. The positions of the cooling medium inlet and outlet are determined based on the specific layout of the object being cooled. Generally, to achieve higher heat exchange efficiency, a counter-current inlet and outlet layout is used. For pure natural convection heat exchange, the inlet and outlet positions have no impact on heat exchange.

[0010] Furthermore, each channel of the "hexagonal" flow channel structure unit has an interior angle of 120° and the same side length, exhibiting central symmetry.

[0011] The geometric parameters of the spiderweb-like bionic structure refer to the dimensional parameters of the mesh structure formed by the spiderweb-like fractal flow channel units. These structural parameters include, but are not limited to, the ratio of pipe diameter to pipe spacing, bifurcation angle, aspect ratio of the channel cross-section, inlet shape, and number of flow channels.

[0012] Furthermore, for the mesh structure formed by the spiderweb biomimetic fractal flow channel unit, the pipe diameter is generally arranged according to the actual size of the specific cooling object. Typically, in order to obtain a better heat exchange effect, the pipe diameter is on the order of millimeters, about 2 to 4 mm. The ratio of pipe diameter to pipe spacing is generally 0.5 to 1.5, the bifurcation angle is 120°, and the length-to-width ratio of the channel cross section is generally set in the range of 0.8 to 1.2. The inlet shape can be rectangular or circular. In order to ensure a good heat exchange effect and reduce the complexity of engineering design, the number of flow channels should be set in a way that makes full use of the available space of the cooling object without causing over-cooling.

[0013] The aforementioned cooling channel scheme refers to the final cooling channel design scheme that meets the cooling requirements of complex curved spatial structures.

[0014] The present invention adopts the above technical solution, which has the following advantages:

[0015] 1. The active cooling microchannel structure designed using biomimetic principles in this invention can significantly increase the heat exchange area and achieve smaller flow losses and more uniform temperature distribution while ensuring heat exchange performance.

[0016] 2. This invention forms a "diversion-convergence" mesh flow channel through the arrangement of a spider web-type cooling flow channel structure, which can meet the actual inlet and outlet setting requirements and achieve uniform distribution of cooling fluid flow. While ensuring the cooling effect, it has strong feasibility.

[0017] 3. Based on fractal theory, this invention can be applied to the design of cooling channels for various complex curved surfaces by optimizing structural parameters and arrangement.

[0018] Based on the above reasons, this invention can be applied to high heat flux component structures in heat transfer fields such as aviation, aerospace, and energy. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the technical solutions of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 Design scheme for a complex curved surface space cooling channel with a spider web biomimetic structure. Among them, (a) is a three-dimensional schematic diagram of the overall structure of the elliptical complex curved surface mesh fractal cooling channel, and (b) is a three-dimensional schematic diagram of the mesh fractal cooling channel.

[0021] Figure 2It is a "hexagonal" flow channel structure unit.

[0022] Figure 3 The diagram shows a two-dimensional flow channel plane composed of spiderweb-shaped fractal flow channel units arranged in a "split-convergence" manner. This plane is used for subsequent projection into three-dimensional space.

[0023] Figure 4 The simulation results (in K) for the structural heat transfer temperature in the specific embodiment are shown. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. In this embodiment, the cooling channel scheme of the present invention is used to complete the design of an elliptical complex curved surface fractal cooling channel scheme.

[0025] An elliptical complex curved surface fractal cooling channel scheme is proposed, the design of which is as follows: Figure 1 As shown. The complex elliptical surface is mainly based on the airfoil design of conventional aircraft wings. To simplify the design, the airfoil cross-section is set to be elliptical, with a major axis of 60mm, a minor axis of 35mm, a cross-sectional width of 6mm, and an airfoil length of approximately 90mm along the flow direction.

[0026] The specific design scheme is as follows: First, based on fractal theory, the structural parameters of the "hexagonal" flow channel structure unit are adjusted on the plane. Multiple spiderweb-shaped fractal flow channel units are connected by connecting vertices. Referring to the "divergence-convergence" flow channel design and combined with the "L"-shaped cooling flow channel scheme, the inlet and outlet channels are rationally arranged. The planar design is as follows: Figure 3 As shown. The structural parameters of the hexagonal flow channel unit include the pipe diameter to pipe spacing ratio, bifurcation angle, length-to-width ratio, inlet shape, etc., such as... Figure 2 As shown. Among them, combined with Figure 2 To ensure the "hexagonal" characteristic of the baseline channel layout, the channel center angle θ is set to 60°, and the internal center radius R of the channel is... in =1mm, R out =36mm, channel width W c =1mm, channel spacing W d =1mm. That is, the ratio of the channel diameter to the spacing between pipes is 1.0, and the channel inlet development section L in =11.5mm, and at the same time, in order to reduce the flow resistance inside the cooling channel, the outlet channel width W is set. d_out It is 1.6mm, slightly larger than the width of the inlet channel (W). d_in=1mm). Finally, the flow channel arrangement is mapped onto the spatial curved surface to form a cooling channel scheme. The cooling medium flows in from the middle of the head of the curved spatial structure and flows out from both sides of the ends of each fractal flow channel.

[0027] In this embodiment, the heat transfer performance of the design scheme was simulated using the CFD method. The calculation results show that the design scheme can meet the cooling requirements of the structure. The simulation results of heat transfer are shown in [the figure]. Figure 4 It can be seen that in the central region of the curved mesh fractal cooling channel, the surface temperature of the structure is relatively low, ranging from 310K to 320K. The overall temperature distribution of the structure is relatively reasonable, the high-temperature area is small, and the surface and internal areas of the structure are well cooled and protected. At the same time, due to the arrangement of the outlet areas on both sides, the temperature distribution at the outlet position is low, and the peak temperature does not exceed 410K, which meets the allowable temperature requirements of the material. The design scheme is reasonable and feasible.

[0028] The above description is merely one specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations and substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A design method for complex curved surface space cooling channels based on spider web biomimetic structures, characterized in that, This method designs a spider web-like bionic structure based on the characteristics of complex curved surface spatial structures, extracts the geometric structural parameters of the spider web-like bionic structure, and uses three-dimensional curved surface topology mapping technology to realize the design scheme of cooling channels inside the curved surface space, ultimately meeting the cooling requirements of complex curved surface spatial structures. The complex curved surface spatial structure features refer to the surface shape of the three-dimensional curved surface, the distribution of heat load on the surface, and the location of the inlet and outlet of the cooling medium; The aforementioned spider web biomimetic structure refers to a spider web-shaped cooling channel structure unit based on biomimetic ideas, which includes "hexagonal" channel structure units and "L"-shaped channel structure units. At the same time, multiple fractal channel units are combined based on fractal theory to form a complex channel that is first dispersed and then converged. The geometric parameters of the aforementioned spider web biomimetic structure include the ratio of pipe diameter to pipe spacing, bifurcation angle, aspect ratio of channel cross-section, inlet shape, and number of flow channels.

2. The design method for a complex curved surface space cooling channel based on a spider web biomimetic structure according to claim 1, characterized in that, Based on the surface shape and curvature distribution of the three-dimensional spatial surface, hexagonal flow channel structural units are arranged in areas with peak heat loads above 60%, and L-shaped flow channel structural units are set in areas with peak heat loads below 40% to match the overall flow channel inlet and outlet design; the positions of the cooling medium inlet and outlet are determined according to the specific layout of the actual cooling object.

3. The design method for a complex curved surface space cooling channel based on a spider web biomimetic structure according to claim 2, characterized in that, Using a counter-current approach for the layout of the cooling medium inlet and outlet has no impact on heat transfer in the case of pure natural convection heat transfer.

4. The design method for a complex curved surface space cooling channel based on a spider web biomimetic structure according to claim 1, characterized in that, Each channel of the "hexagonal" flow channel structure unit has an interior angle of 120° and the same side length, exhibiting central symmetry.

5. The design method for a complex curved surface space cooling channel based on a spider web biomimetic structure according to claim 1, characterized in that, For the mesh structure formed by the spider web biomimetic fractal flow channel unit, the pipe diameter is arranged according to the actual size of the specific cooling object.

6. The design method for a complex curved surface space cooling channel based on a spider web biomimetic structure according to claim 5, characterized in that, For the mesh structure formed by the spider web biomimetic fractal flow channel unit, the pipe diameter is on the order of millimeters, ranging from 2 to 4 mm, the ratio of pipe diameter to pipe spacing is 0.5 to 1.5, the bifurcation angle is 120°, the length-to-width ratio of the channel cross-section is set in the range of 0.8 to 1.2, and the inlet shape adopts a rectangular or circular cross-section. The number of flow channels should be set in a way that utilizes the available space of the object being cooled without causing excessive cooling.

Images