Aluminum alloy heat pipe bearing and heat conduction integrated simulation analysis method and system combined with VOF gas-liquid two-phase flow model

Abstract

The aluminum alloy heat pipe bearing and heat conduction integrated simulation analysis method and system combined with a VOF gas-liquid two-phase flow model are provided, the VOF gas-liquid two-phase flow model suitable for the aluminum alloy heat pipe is constructed, a plurality of representative flow guide unit styles are selected, and geometrical characteristic parameters of the representative flow guide unit styles are extracted; the method comprises the following steps: simplifying a three-dimensional heat pipe into two-dimensional geometric models on the premise of ensuring accurate characterization of a heat conduction path, then respectively coupling a plurality of two-dimensional geometric models with a VOF gas-liquid two-phase flow model, constructing a heat pipe finite element model comprising different flow guide units, performing multi-physics field simulation, and outputting simulation data; performing quantitative evaluation on different diversion styles based on simulation data, screening out an optimal style, setting a plurality of parameterized design variables for the optimal style, and constructing a plurality of finite element models; therefore, multiple rounds of finite element simulation analysis are carried out, the heat dissipation performance under different parameters is compared, the optimal parameters are finally determined, and optimal design of the overall strength bearing and heat conduction performance of the aluminum alloy heat pipe is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat pipe design, and more particularly to an aluminum alloy heat pipe bearing and heat conduction integrated simulation analysis method and system combined with a VOF (Volume of Fluid) gas-liquid two-phase flow model. BACKGROUND

[0002] As a kind of high-efficiency passive heat transfer element, heat pipes are widely used in electronic packaging, power system cooling and other fields due to their good isothermality and heat conduction performance. In particular, in light heat pipe devices made of aluminum alloy, the low cost, high thermal conductivity and good mechanical strength make them show important value in large-scale electronic equipment heat dissipation solutions.

[0003] In the actual working process of traditional heat pipes, the rapid transfer of heat is realized by the gas-liquid phase change of the flow in the closed cavity: the liquid flow absorbs heat and vaporizes at the evaporation end, the gaseous flow moves to the condensation end and releases latent heat before condensing back, thus forming a complete heat cycle. Therefore, the design of the flow guide unit inside the heat pipe plays a decisive role in the stability of the gas-liquid phase change process, the uniformity of heat flow distribution and the overall heat dissipation efficiency.

[0004] Currently, the research on heat pipe flow guide units mainly focuses on empirical design and experimental comparison, and there is less systematic modeling optimization process. In the simulation of the internal structure of the heat pipe, the common numerical modeling method is difficult to accurately describe the complex multiphase physical processes such as vaporization and condensation, especially in terms of different flow guide unit shapes, arrangement forms and working fluid phase interface evolution, the simulation accuracy and applicability are obviously limited.

[0005] In addition, in the aspect of two-dimensional simplified modeling, due to the lack of a unified parameter system and evaluation method, the existing simulation methods cannot effectively realize the comparison and evaluation between different flow guide units, and it is difficult to support an efficient and quantifiable structure optimization design process. SUMMARY

[0006] The present application provides an aluminum alloy heat pipe bearing and heat conduction integrated simulation analysis method and system combined with a VOF gas-liquid two-phase flow model. Based on the VOF gas-liquid two-phase flow model, the present application has the capabilities of geometric quantifiable modeling of flow guide units, comprehensive analysis of performance indicators and optimal search of structure parameters, can simultaneously consider the heat conduction efficiency of gas-liquid flow and the bearing stability of the overall strength of the flow guide structure, and realize the collaborative improvement of the thermal-mechanical coupling performance of the aluminum alloy heat pipe.

[0007] In a first aspect, the application provides a simulation analysis method for heat pipe load bearing and heat conduction integration of aluminum alloy combined with a VOF gas-liquid two-phase flow model, the method comprising: constructing a VOF gas-liquid two-phase flow model and setting a control equation group containing momentum conservation, energy conservation and mass conservation; selecting multiple guide flow unit patterns and characterizing and quantifying geometric characteristic parameters of the multiple guide flow unit patterns, and then simplifying the three-dimensional heat pipes of the multiple guide flow unit patterns into multiple heat pipe two-dimensional geometric models; combining the multiple heat pipe two-dimensional geometric models with the VOF gas-liquid two-phase flow model for finite element simulation, constructing multiple heat pipe finite element models with different guide flow unit patterns and extracting simulation output data of each heat pipe finite element model; establishing a heat pipe performance evaluation function by using a weight distribution method and calculating heat pipe comprehensive indexes of the multiple guide flow units according to the heat pipe performance evaluation function and the simulation output data, and then generating an optimal guide flow unit pattern; performing multi-parameter finite element simulation on the optimal guide flow unit pattern, constructing heat pipe finite element models with different guide flow unit parameters, and then outputting guide flow unit parameters with the best performance.

[0008] In an optional solution of the first aspect, when the VOF gas-liquid two-phase flow model is constructed, the method comprises: defining the gas-liquid interface variation of the VOF gas-liquid two-phase flow model by using a volume fraction equation: wherein is a volume fraction, the value of which is between 0 and 1; t is time, is a gradient operator, is a fluid velocity; the gas-liquid fluid density is calculated by using a weighted average method of the volume fraction: wherein is a mixed volume density, and are fluid densities.

[0009] In an optional solution of the first aspect, when the control equation group is set, the method comprises: setting the momentum equation of the gas phase according to Newton's second law and according to the pressure gradient, gravity, viscosity and the interaction between the two phases: and setting the momentum equation of the liquid phase: wherein is a gas phase density, is a gas phase velocity, is a fluid pressure, is a gravitational acceleration, is a stress tensor of the gas phase, is an interaction force between the gas phase and the liquid phase, is a liquid phase density, is a liquid phase velocity, is a stress tensor of the liquid phase; setting the energy equation and the volume fraction equation of the liquid phase in the heating and vaporization stage: , wherein is the total energy per unit mass, is the velocity of the fluid, is the thermal conductivity, is the temperature, is the heat source term in the vaporization process, which is related to the latent heat of vaporization of the condensing agent; is the source term reflecting the volume fraction of the process of liquid turning into gas; the energy equation and the volume fraction equation of the gaseous ascending and condensing stages are set as follows:

[0010] , wherein is the heat source term in the condensation process, which corresponds to the latent heat of condensation of the condensing agent; is the source term reflecting the volume fraction of the process of gas turning into liquid; the momentum equation and the mass conservation equation of the liquid condensing agent droplet falling and flowing stages are set as follows:

[0011] , wherein is the viscosity of the fluid, is the force caused by gravity.

[0012] In an optional solution of the first aspect, the planar geometry of the selected flow guide unit pattern comprises at least two of a ring sector, a rectangle, a square, a triangle, an ellipse, an S shape, a circle, a pencil shape, a honeycomb shape, and a regular polygon.

[0013] In an optional solution of the first aspect, in characterizing and quantifying the geometric characteristic parameters of the plurality of flow guide unit patterns, the method comprises: defining a cavity entity area ratio : wherein is the total area of the internal cavity of the two-dimensional heat pipe, is the total area occupied by the flow guide unit in the two-dimensional heat pipe; defining a sum of all flow guide unit side lengths : , is the sum of the side lengths of a single flow guide unit.

[0014] In an optional solution of the first aspect, in simplifying the plurality of flow guide unit patterns of the three-dimensional heat pipe into a plurality of two-dimensional geometric models of heat pipes, the method comprises: converting the flow guide units in the three-dimensional heat pipe into a two-dimensional planar structure with equivalent flow guide path lengths and channel cross sections by using an equivalent planar projection method; and realizing the regulation of the fluid channel path by controlling the geometric characteristic parameters of the flow guide units, so as to reflect the actual fluid distribution and flow behavior in the two-dimensional planar structure of the heat pipe.

[0015] In one alternative to the first aspect, when constructing the finite element model of the heat pipe, the method includes: defining the heat pipe material; defining the filling fluid type, filling ratio, and physical property parameters of the filling fluid; setting the solver type to a pressure-based solver and setting the time to transient, setting the maximum number of iterations and the convergence criterion; setting the multiphase model of the finite element simulation to a VOF gas-liquid two-phase flow model; setting thermal boundary conditions; setting the initial velocity, temperature, and gravity, and setting the initial fluid distribution ratio of the heat pipe; setting the discretization scheme of the finite element simulation as follows: for flow, using second-order upwind difference; for energy, using standard difference.

[0016] In one alternative embodiment of the first aspect, the method for calculating the overall heat pipe performance index includes: collecting temperature distribution parameters from various temperature monitoring points; and assigning a membership degree calculation formula to each temperature distribution parameter based on a weighted analysis method. ,in For the membership degree of the indicator, For normalized index values, This represents the i-th simulation group. This represents the j-th evaluation indicator. Indicates the first The minimum value of each evaluation indicator. Indicates the first The maximum value of each evaluation index; calculate the comprehensive score of temperature distribution characteristics:

[0017] ,in This represents the overall score. Weighting coefficients are used to calculate the average vertical displacement of the fluid front point. ,in This represents the average vertical displacement. Let t be the position of the gas phase front point in the t-th simulation analysis step. The coordinates of the initial evaporation starting point are given, and N represents the total number of sampling simulation analysis steps; the fluid velocity distribution is identified.

[0018] In one alternative embodiment of the first aspect, when calculating the vertical average displacement of the fluid front point, the method further includes: constructing a gas phase distribution threshold based on the volume fraction and screening out gas phase regions based on the gas phase distribution threshold; scanning all grid cells in the gas phase region in the vertical direction; extracting the gas phase front region using the maximum connected component method; calculating the centroid coordinates based on the geometric center coordinates of all grid cells in the gas phase front region; and using the centroid coordinates as the position of the gas phase front point.

[0019] In a second aspect, the application provides an aluminum alloy heat pipe bearing and heat conduction integrated simulation analysis system using the method according to any one of the first aspect, combined with a VOF gas-liquid two-phase flow model, comprising: a two-phase model construction module, configured to construct a VOF gas-liquid two-phase flow model and set a control equation group containing momentum conservation, energy conservation and mass conservation; a two-dimensional model simplification module, configured to select a plurality of flow guide unit styles and characterize and quantify the geometric feature parameters of the plurality of flow guide unit styles, and then simplify the three-dimensional heat pipe of the plurality of flow guide unit styles into a plurality of heat pipe two-dimensional geometric models; a finite element simulation module, configured to combine the plurality of heat pipe two-dimensional geometric models with the VOF gas-liquid two-phase flow model to perform finite element simulation, construct a plurality of heat pipe finite element models with different flow guide unit styles, and extract simulation output data of each heat pipe finite element model; and further configured to perform finite element simulation on the optimal flow guide unit style with multiple parameters, and construct heat pipe finite element models with different flow guide unit parameters; an optimization design output module, configured to establish a heat pipe performance evaluation function using a weight allocation method, and calculate a heat pipe comprehensive index of the plurality of flow guide units according to the heat pipe performance evaluation function and the simulation output data, and then generate an optimal flow guide unit style; and further configured to output a flow guide unit parameter with the best performance.

[0020] It should be understood that the general description above and the following detailed description are only exemplary and do not limit the application. BRIEF DESCRIPTION OF DRAWINGS

[0021] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate one or more embodiments of the application and, together with the description, serve to explain the principles of the application and to enable a person skilled in the relevant art to make and use the application.

[0022] Figure 1 is a schematic diagram of the heat dissipation principle of an exemplary S-shaped heat pipe according to some embodiments of the application.

[0023] Figure 2 is a schematic diagram of an exemplary heat pipe two-dimensional geometric model with different flow guide units according to some embodiments of the application; wherein (a) is a circular flow guide unit, (b) is an S-shaped flow guide unit, (c) is a pencil-shaped flow guide unit, and (d) is a honeycomb-shaped flow guide unit.

[0024] Figure 3 is a schematic diagram of an exemplary heat pipe two-dimensional finite element model with different flow guide units according to some embodiments of the application; wherein (a) is a circular flow guide unit, (b) is an S-shaped flow guide unit, (c) is a pencil-shaped flow guide unit, and (d) is a honeycomb-shaped flow guide unit.

[0025] Figure 4is a schematic diagram of the phase change process of gas-liquid in a given simulation step according to some embodiments of the present application; wherein (a) is the 2000th simulation step, and (b) is the 4000th simulation step.

[0026] Figure 5 is a schematic diagram of the temperature field of four kinds of flow guide units at the 6000th simulation step according to some embodiments of the present application; wherein (a) is a circular flow guide unit, (b) is an S-shaped flow guide unit, (c) is a pencil-shaped flow guide unit, and (d) is a honeycomb-shaped flow guide unit.

[0027] Figure 6 is a schematic diagram of the velocity vector distribution of four kinds of flow guide units according to some embodiments of the present application; wherein (a) is a circular flow guide unit, (b) is an S-shaped flow guide unit, (c) is a pencil-shaped flow guide unit, and (d) is a honeycomb-shaped flow guide unit.

[0028] Figure 7 is a schematic diagram of the vertical average displacement of the fluid front point of four kinds of flow guide units with the change of the simulation step length according to some embodiments of the present application.

[0029] Figure 8 is a schematic diagram of the velocity distribution radar chart of the simulation model of four kinds of flow guide units after the steady state according to some embodiments of the present application; wherein (a) is a circular flow guide unit, (b) is an S-shaped flow guide unit, (c) is a pencil-shaped flow guide unit, and (d) is a honeycomb-shaped flow guide unit.

[0030] Figure 9 is a schematic diagram of the comprehensive score of the temperature distribution characteristics of the heat pipe of four kinds of flow guide units according to some embodiments of the present application.

[0031] Figure 10 is a schematic diagram of the geometric model of the heat pipe with different numbers of units in a given flow guide unit form according to some embodiments of the present application; wherein (a) is a heat pipe with 31 flow guide units and marked as , (b) is a heat pipe with 58 flow guide units and marked as , and (c) is a heat pipe with 108 flow guide units and marked as .

[0032] Figure 11 is a schematic diagram of the vertical average displacement of the fluid front point of three kinds of number of flow guide unit models with the change of the simulation according to some embodiments of the present application.

[0033] Figure 12 is a schematic diagram of the velocity distribution radar chart of three kinds of number of flow guide unit models after the steady state according to some embodiments of the present application; wherein (a) is the group, and (b) is group, (c) is group.

[0034] Figure 13 is an exemplary different number of honeycomb-shaped flow guide unit heat dissipation performance comprehensive evaluation value schematic diagram according to some embodiments of the application.

[0035] Figure 14 is an exemplary aluminum alloy heat pipe bearing and heat conduction integrated simulation analysis method flowchart combining the VOF gas-liquid two-phase flow model according to some embodiments of the application.

[0036] Figure 15 is an exemplary aluminum alloy heat pipe bearing and heat conduction integrated simulation analysis system module connection schematic diagram combining the VOF gas-liquid two-phase flow model according to some embodiments of the application.

[0037] Figure 16 is an exemplary electronic device connection schematic diagram according to some embodiments of the application. DETAILED DESCRIPTION

[0038] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations can be implemented in any

[0039] Currently, the mainstream theoretical model that can be used for heat pipe heat dissipation analysis can be divided into three categories according to the different flow heat dissipation processes, namely, phase flow model, energy model and turbulence model, as shown in the following table:

[0040] Table: selection of heat analysis theoretical model

[0041]

[0042] In the present application, considering that the heat pipe is filled with cooling liquid medium and involves gas-liquid two-phase flow problems, which is very suitable for the application scene of VOF, therefore, the VOF gas-liquid two-phase flow model is selected as the heat analysis theoretical model of the present application.

[0043] The VOF gas-liquid two-phase flow model can be described by the volume fraction equation, which reflects the change of the volume proportion of a part of the fluid with time and space, and its basic form is: wherein, is the volume fraction, whose value is between 0 and 1; t is time, is the gradient operator, is the fluid velocity, is the partial derivative.

[0044] Within the heat pipe control volume, the properties of the fluid (such as density and viscosity) are calculated based on the weighted average of the volume fraction. Considering the existence of gas-liquid two-phase fluid in the heat pipe, the density can be expressed as: where, is the mixture volume density, and is the fluid density.

[0045] Specifically, for the two-dimensional heat pipe containing gas-liquid two-phase medium in this application, the heat dissipation process can be expressed as the mass, momentum, and energy equations, where:

[0046] Before describing the gas-liquid two-phase change process, a momentum equation needs to be established for each phase. Based on Newton's second law and considering the pressure gradient, gravity, viscosity, and interaction between the two phases, the momentum equation for the gas phase is set as: and the momentum equation for the liquid phase is set as: where is the gas phase density, is the gas phase velocity, is the fluid pressure, is the gravitational acceleration, is the stress tensor of the gas phase (usually related to the viscosity of the gas phase), is the interaction force between the gas and liquid phases, is the liquid phase density, is the liquid phase velocity, is the stress tensor of the liquid phase (related to the viscosity of the liquid phase). This set of momentum equations provides a basis for describing the gas-liquid two-phase interface interaction and heat and mass transfer process in the subsequent VOF gas-liquid two-phase flow model.

[0047] The energy and volume fraction equations are further described according to different stages of the flow process:

[0048] (1) Liquid heating and vaporization

[0049] When the liquid condensate is heated by the heat source and reaches the boiling point, it will start to vaporize; at this time, the energy equation and the volume fraction equation are respectively: , where is the total energy per unit mass, is the fluid velocity, is the thermal conductivity, is the temperature, is the heat source term during vaporization, which is related to the latent heat of vaporization of the condensant; is the source term for the volume fraction of the process of liquid turning into gas; wherein these two equations collectively describe the physical mechanism in the phase change process, the energy equation indicates that the vaporization process needs to absorb heat, which does not cause temperature rise but is used to complete the phase change; the volume fraction equation indicates that after the liquid vaporizes, the proportion of the gas phase increases, and this conversion rate is controlled by the vaporization rate; through and are associated with each other, so as to realize the coupling between thermodynamics and fluid dynamics.

[0050] (2) Gaseous rising and condensing

[0051] When the condensing agent vaporizes into a gaseous state, it will rise due to its lower density. When it contacts a cold source, the gas will condense and release latent heat; at this time, the energy equation and the volume fraction equation are respectively:

[0052] , wherein is the heat source term in the condensation process, corresponding to the condensation latent heat of the condensing agent; is the source term for the volume fraction of the process of gas turning into liquid; wherein these two equations collectively describe that after the condensing agent evaporates, it becomes a gas with lower density and has an upward trend (affected by buoyancy), when the rising gas encounters a cooling wall or a cold source (low-temperature area), a gas-liquid phase change occurs, and in the condensation process, the gas to liquid conversion releases latent heat.

[0053] (3) Liquid condensing agent dripping and flowing

[0054] When the gaseous condensing agent turns back into a liquid state, it will drip due to the action of gravity. This process mainly involves the momentum equation and the mass conservation equation, wherein the momentum equation is: wherein is the fluid viscosity, is the force due to gravity, which is downward for the liquid part. The mass conservation equation is: ; wherein these two equations collectively describe that in the process of the condensing agent vaporizing and then condensing into a liquid state and dripping under the action of gravity, the fluid behavior is controlled by the momentum equation and the mass equation; the momentum equation describes the accelerated falling process of the liquid droplets under the action of gravity, which is mainly controlled by pressure, viscous resistance and gravity; the mass conservation equation ensures that there is no abnormal accumulation of mass in the entire condensing-dripping flow field, maintaining the continuity of the fluid.

[0055] In actual implementation, the fluent fluid simulation module of the Ansys Workbench software can also be used to carry out finite element simulation modeling and optimization analysis.

[0056] Reference Figure 1as shown, Figure 1 The schematic diagram of heat dissipation principle of the S-shaped heat pipe is shown, and the size is given as 100mmx50mmx5mm. Figure 1 In the S-shaped heat pipe, a plurality of plate-shaped flow guide units are arranged at intervals to form an S-shaped flow channel. The heat pipe is filled with refrigerant liquid. The vaporization in the heating area and the condensation in the condensation area in the heat pipe can quickly transfer heat, thereby achieving heat dissipation. In order to improve the efficiency of simulation analysis, the three-dimensional S-shaped heat pipe is simplified as a two-dimensional model located on the plane ABCD in the figure for modeling and analysis. At this time, the three-dimensional plate-shaped flow guide unit is simplified as a rectangular two-dimensional flow guide unit. In actual engineering, the flow guide unit is various and needs to be optimized and designed.

[0057] In the embodiments of the present application, the flow guide unit forms that can be selected for the two-dimensional simplified model of the heat pipe include ring fan-shaped, triangular, circular, elliptical and various planar geometric shapes. According to the physical principle and heat transfer theory, the advantages and disadvantages of the heat dissipation performance of the above flow guide units are preliminarily inferred, but the actual performance difference needs more detailed simulation and experimental verification. The specific contents are shown in the following table:

[0058] Table: Heat pipe flow guide unit form and performance analysis

[0059]

[0060] As can be seen from the table, the influence of shape on heat dissipation performance is related to the flow resistance of fluid and the change of effective heat dissipation area. Generally, circular and polygonal shapes (such as regular pentagon and regular hexagon) can provide the best performance balance, while sharp angle shapes (such as triangle) can cause local flow resistance, thereby affecting performance. Based on the above analysis, in order to reduce the scale of simulation analysis, four typical flow guide units, such as circular, S-shaped, pencil-shaped and honeycomb-shaped, are selected in this example, and the two-dimensional geometric model of the heat pipe with different flow guide units is established as shown in Figure 2 as shown, Figure 2 The schematic diagram of the two-dimensional geometric model of the heat pipe with different flow guide units is shown, wherein, Figure 2 (a) of which is a circular flow guide unit, Figure 2 (b) of which is an S-shaped flow guide unit, Figure 2 (c) of which is a pencil-shaped flow guide unit, Figure 2 (d) of which is a honeycomb-shaped flow guide unit. In this way, the subsequent flow guide unit style optimization simulation analysis is used.

[0061] The process of characterizing and assigning the geometric characteristic parameters of the flow guide unit is as follows:

[0062] The cavity solid area ratio is defined as : , wherein is the total area of the two-dimensional heat pipe internal cavity, This refers to the total area occupied by the flow guiding unit inside the two-dimensional heat pipe.

[0063] Define the sum of the side lengths of all flow guiding elements. : , This is the sum of the side lengths of a single flow guiding unit.

[0064] The heat dissipation performance of a heat pipe is closely related to the structure and design parameters of its internal airflow guiding unit. This is measured by the ratio of the cavity's solid area to... For example, on the one hand, when When it increases, it means the internal cavity area of ​​the heat pipe... Relative to the area of ​​the flow guiding unit Increasing the cavity size may provide a larger effective heat dissipation area, thereby increasing heat dissipation efficiency; however, due to the increased cavity size, the fluid flow path may be reduced, resulting in a lower pressure drop; on the other hand, when When it decreases, it means the internal cavity area of ​​the heat pipe decreases. Relative to the area of ​​the flow guiding unit Reducing the size of the flow guide unit may decrease the effective heat dissipation area, thereby reducing heat dissipation efficiency; however, due to the increase in the number or size of the flow guide unit, the flow path of the fluid may increase, resulting in a greater pressure drop.

[0065] To facilitate comparison of the heat dissipation performance of the four types of heat pipes mentioned above, and to further reduce the simulation scale, under a given... , , Under this premise, a heat pipe geometric model with an outer dimension of 100mm×50mm is established.

[0066] In some embodiments of this application, ANSYS software can be used for finite element simulation, and the specific process is as follows:

[0067] Will as Figure 2 The heat pipe 2D geometric model shown is imported into the ANSYS Mesh module of the software, and further established as follows: Figure 3 As shown, Figure 3 This application shows schematic diagrams of two-dimensional finite element models of heat pipes with different flow guiding units according to some embodiments, wherein, Figure 3 (a) is a circular flow guide unit. Figure 3 (b) is an S-shaped flow guide unit. Figure 3 (c) is a pencil-shaped flow guide unit. Figure 3 (d) is a honeycomb-shaped flow guiding unit. Figure 3 In this process, R134a refrigerant liquid was selected as the filling liquid, with a filling ratio of 30%. Its thermophysical parameters are shown in the table below:

[0068] Table: Physical Properties of R134a Refrigerant

[0069]

[0070] The heat pipe is made of aluminum alloy. The solver type is selected as pressure-based solver, the time is set to transient, the multiphase model is selected as the VOF homogeneous model, and the thermal boundary condition is set to a heat flux of 2139.98 W / m² for the heat source on the AB bottom surface. 2 The thermally relevant boundary conditions on both sides of AD and BC are convection-based, with a heat transfer coefficient of 396.28 W / (m²). 2 The initial velocity was set to 0, the initial temperature to room temperature (25°C), and the initial fluid distribution covered approximately 30% of the flat plate heat pipe. The discretization scheme was set as follows: second-order upwind difference for flow and standard difference for energy. The solver parameters were set to a maximum of 20 iterations, a convergence criterion of 1e-6, and gravity of 9.81 m / s². 2 down.

[0071] Therefore, the heat dissipation performance of a heat pipe can be characterized by the following parameters:

[0072] (1) Temperature distribution characteristics at observation points: Figure 1 In this process, five temperature monitoring points—P, Q, R, S, and T—are set up. Further statistical analysis is conducted to obtain the statistical parameters of the temperature distribution characteristics at these monitoring points under a given analysis step, including the maximum temperature. Average temperature And temperature variance D.

[0073] (2) Comprehensive score of temperature distribution characteristics: In order to comprehensively evaluate the quality of temperature distribution characteristics at the observation points, a comprehensive score of average temperature is given. Extreme temperature Given the temperature variance D and the corresponding weights, based on the weighted analysis method, the membership degree calculation formula is given: ,in For the membership degree of the indicator, For normalized index values, This represents the i-th simulation group. This represents the j-th evaluation indicator. Indicates the first The minimum value of each evaluation indicator. Indicates the first The maximum value of each evaluation indicator.

[0074] The comprehensive score for temperature distribution characteristics is given by the formula: ,in This represents the overall score. These are the weighting coefficients. The weighting coefficients are shown in the table below:

[0075] Table: Weighting coefficients for each evaluation indicator

[0076]

[0077] (3) Calculate the average vertical displacement of the fluid front point: ,in This represents the average vertical displacement. Let t be the position of the gas phase front point in the t-th simulation analysis step. The coordinates of the initial evaporation starting point are given, and N is the total number of sampling simulation analysis steps. This is used to evaluate the fluid heat dissipation efficiency; the higher the value, the faster the evaporated gas reaches the cold source.

[0078] (4) Identify the fluid velocity distribution to evaluate the distribution of the fluid velocity direction in a given simulation analysis step and check for the presence of vortex regions.

[0079] Therefore, the simulation results are as follows:

[0080] Gas-liquid phase transition field: All four simulations described above show a clear gas-liquid phase transition process. Taking an S-shaped heat pipe as an example, refer to... Figure 4 As shown, Figure 4 The following diagram illustrates the gas-liquid phase transition process within a given simulation analysis step of some embodiments of this application, wherein... Figure 4 (a) represents 2000 simulation analysis steps. Figure 4 (b) represents 4000 simulation analysis steps. This verifies that... Figure 1 The heat dissipation principle is shown.

[0081] Temperature field: reference Figure 5 As shown, Figure 5 The following are temperature field contour plots of four flow guiding units from some embodiments of this application, simulated up to 6000 steps. Figure 5 (a) is a circular flow guide unit. Figure 5 (b) is an S-shaped flow guide unit. Figure 5 (c) is a pencil-shaped flow guide unit. Figure 5 (d) is a honeycomb-shaped flow guiding unit. Figure 5 It can be seen that the temperature field cloud map distribution of both honeycomb structure and circular structure is relatively uniform, and the temperature field distribution uniformity corresponding to honeycomb structure is better than that of circular structure; while the flow path of pencil structure is straight, the temperature extreme value difference is large and the distribution is more concentrated on both sides.

[0082] Velocity vector field: reference Figure 6 As shown, Figure 6 The following diagrams illustrate the simulated velocity vector distribution of four flow guiding units according to some embodiments of this application. Figure 6 (a) is a circular flow guide unit. Figure 6 (b) is an S-shaped flow guide unit. Figure 6 (c) is a pencil-shaped flow guide unit. Figure 6(d) is a honeycomb-shaped flow guiding unit. By Figure 6 It can be seen that the S-shaped structure has obvious vortex phenomenon in the internal velocity vector field, which may lead to poor fluid flow; the pencil-shaped and circular structure have obvious extreme values in the velocity vector field, and the specific location is below the flow guiding unit, which also indicates that the fluid is hindered during flow; and the honeycomb-shaped structure has a relatively uniform internal velocity vector field distribution, which indicates that the fluid has better flowability.

[0083] Fluid vertical displacement: refer to Figure 7 , Figure 7 Fig. 4 shows a schematic diagram of the vertical average displacement of the fluid front point of the four flow guiding units of some embodiments of the present application with the change of the simulation step. By Figure 7 It can be seen that the pencil-shaped structure can reach the upper cold source faster than the other structures; the S-shaped structure reaches the upper cold source at the slowest speed; the vertical movement speed of the circular structure and the honeycomb-shaped structure is not much different, but the honeycomb-shaped structure is still one step faster.

[0084] Velocity direction distribution: refer to Figure 8 , Figure 8 Fig. 6 shows a radar chart of the velocity distribution of the simulation model of the four flow guiding units of some embodiments of the present application after reaching a steady state, wherein Figure 8 (a) is a circular flow guiding unit, Figure 8 (b) is an S-shaped flow guiding unit, Figure 8 (c) is a pencil-shaped flow guiding unit, Figure 8 (d) is a honeycomb-shaped flow guiding unit. By Figure 8 It can be seen that the pencil-shaped and S-shaped structures have a large velocity component in the vertical and horizontal directions, respectively; and the velocity direction of the circular and honeycomb-shaped structures is relatively stable, and the velocity of the honeycomb-shaped structure is more stable than that of the circular structure.

[0085] Temperature distribution characteristic comprehensive score: refer to the table below:

[0086] Table: statistical parameters of temperature distribution characteristics of observation points (after normalization)

[0087]

[0088] The temperature distribution characteristic comprehensive scores of the four heat pipes are further calculated, as shown in Figure 9 , Figure 9 Fig. 8 shows a schematic diagram of the temperature distribution characteristic comprehensive score of the heat pipe of the four flow guiding units of some embodiments of the present application. By Figure 9 It can be seen that under the same conditions, the temperature distribution characteristic of the heat pipe with the honeycomb-shaped flow guiding unit is the best.

[0089] Specifically, the honeycomb-shaped flow guide unit has a periodic symmetric structure, forms a polygonal closed unit in a two-dimensional plane, has a good isotropic mechanical response capability, can effectively disperse stress concentration caused by thermal expansion and contraction or internal pressure difference in the evaporation section, the condensation section and other areas, and thus significantly improves the structural bearing stability of the heat pipe under the conditions of working condition fluctuation or cyclic load. Specifically, the honeycomb-shaped flow guide unit has the following mechanical and heat conduction coupling advantages:

[0090] 1. The honeycomb unit provides multi-face support and uniform stress conduction path, which can relieve stress concentration under the action of instantaneous internal pressure when high-pressure vapor phase is rapidly generated at the evaporation end, and avoid local bulging or structural fatigue of the heat pipe cavity; it can form a stable distributed support network, which has high specific stiffness and specific strength in vertical and horizontal directions, and improves the overall deformation resistance of the heat pipe.

[0091] 2. The honeycomb flow guide unit can form more intensive gas phase migration paths after the liquid working medium vaporizes due to its high channel distribution density and multi-directional connection structure, which enhances the heat output efficiency of the high-temperature area; the multi-branch structure of the honeycomb channel can strengthen the convective motion of the evaporated gas and guide the gas phase to quickly converge to the condensation end, reducing heat retention and improving the overall heat conduction response speed.

[0092] 3. The heat-force coupling performance is synergistically improved, under the action of VOF gas-liquid two-phase flow, the honeycomb unit can improve the wall support strength while ensuring the smoothness of the flow path, realizing the synergistic optimization of heat dissipation efficiency and structural stability; both experimental and simulation results show that under the condition of equal heat flux density, the honeycomb flow guide structure has the smallest wall deformation at the high-temperature end while maintaining a low temperature difference, indicating that it has excellent heat load bearing capacity.

[0093] Therefore, the honeycomb-shaped flow guide unit not only performs best in the temperature distribution comprehensive index, but also exhibits good bearing and heat conduction coupling effect due to the mechanical uniformity and thermal conduction continuity of its structure, and is suitable for being selected as the design of the heat pipe flow guide structure.

[0094] Therefore, the overall strength bearing and heat conduction performance of the aluminum alloy heat pipe with the honeycomb-shaped flow guide unit are relatively good, and the embodiments of the present application further simulate the heat pipe with the honeycomb-shaped flow guide unit, under the given 、 conditions, the heat pipe geometric models with different numbers of units under the given flow guide unit form of some embodiments of the present application are established as shown in Figure 10 , Figure 10 Fig. 1 shows the heat pipe geometric model schematic diagram with different numbers of units under the given flow guide unit form of some embodiments of the present application, wherein, Figure 10 Fig. 1(a) is a heat pipe geometric model with 31 flow guide units and labeled as , Figure 10 Fig. 1(b) is a heat pipe geometric model with 58 flow guide units and labeled as , Figure 10(c) is the one with 108 guide flow units and is marked as . In this way, the heat pipe structure parameters are further optimized.

[0095] Therefore, the simulation results are as follows:

[0096] Fluid vertical displacement: refer to Figure 11 , Figure 11 Fig. 3 shows the fluid front point vertical average displacement amount of three quantity guide flow unit models of some embodiments of the application with the change of simulation. It can be seen from Figure 11 that, compared with other groups, Group C can reach the upper cold source faster; and the speed of Group C to reach the upper cold source decreases in turn.

[0097] Velocity direction distribution: refer to Figure 12 , Figure 12 Fig. 4 shows the velocity distribution radar chart of three quantity guide flow unit models in steady state of some embodiments of the application, wherein Figure 12 (a) of Group C, Figure 8 (b) of Group B, Figure 8 (c) of Group A.

[0098] Temperature distribution characteristic comprehensive score: similarly, the observation point temperature distribution characteristic statistical parameters obtained by the simulation of the three groups are normalized, and the specific values are shown in the following table:

[0099] Table: normalized observation point temperature distribution characteristic statistical parameters under the same quantity

[0100]

[0101] Correspondingly, the temperature distribution characteristic comprehensive scores of the three groups of heat pipes are as shown in Figure 13 , Figure 13 Fig. 5 shows the comprehensive evaluation value diagram of the heat dissipation performance of the honeycomb guide flow unit under different quantities of some embodiments of the application. It can be seen from Figure 13 that with the increase of the quantity of the honeycomb guide flow unit, the comprehensive evaluation value of the heat dissipation performance shows a trend of first increasing and then decreasing, which may be because when the quantity of the guide flow unit exceeds a certain value, too many guide flow units make the guide flow path too narrow, thereby affecting the fluid flow.

[0102] In summary, in some embodiments of the application, under the condition that other conditions are the same, when the quantity of the honeycomb guide flow unit is set to 58, the overall strength bearing and heat dissipation performance effect bearing of the aluminum alloy heat pipe are relatively optimal.

[0103] Specifically, further simulation analysis shows that when the number of honeycomb heat pipe units is 58, the aluminum alloy heat pipe achieves the optimal balance between structural load-bearing capacity and thermal conductivity, resulting in the following significant technical effects:

[0104] 1. Optimal overall strength and load-bearing performance: The 58 honeycomb flow guiding units form a uniform and dense structural support network inside the heat pipe, effectively suppressing periodic pressure fluctuations caused by rapid gas-liquid conversion in high-temperature areas. The maximum equivalent stress value of the heat pipe shell under vertical and axial forces is significantly reduced, the stress distribution is more uniform, and the risk of local stress concentration is minimized. Compared with the arrangement of 31 or 108 honeycomb flow guiding units, the 58 units improve the support density per unit area while maintaining sufficient flow channels, achieving the optimal match between specific stiffness and specific strength.

[0105] 2. The thermal conductivity is significantly improved. The 58 honeycomb-shaped flow guiding units can form a well-connected and uniformly distributed network of heat conduction and flow guiding channels, which is conducive to the rapid vaporization of liquid refrigerant after heating by the heat source and allows the gas phase to flow smoothly to the cold source area. Data shows that under the condition of equal heat flow input, the temperature gradient from the middle of the heat pipe to the condensing end is the gentlest, the average temperature drop in the condensing section is the largest, the thermal resistance is the smallest, the gas-liquid interface changes faster, and the average rise rate of the gas phase front point reaches the highest, indicating that its evaporation-condensation efficiency is optimal.

[0106] 3. When the number of honeycomb flow guiding units is too small (e.g., 31), the structural support is sparse and the flow channels are wide, resulting in discontinuous heat conduction and stress concentration. When the number of honeycomb flow guiding units is too large (e.g., 108), although there is good support, the flow guiding channels are excessively compressed, the gas phase flow resistance increases and the heat conduction efficiency decreases. The number of 58 honeycomb flow guiding units is exactly at the critical point of heat conduction continuity and structural balance, achieving the unity of the minimum impedance path of heat flux coupling and the maximum distribution of structural stiffness.

[0107] Therefore, the aluminum alloy heat pipe structure with 58 honeycomb flow guiding units not only achieves better temperature distribution uniformity and gas-liquid conversion efficiency, but also effectively improves the heat pipe's deformation resistance and thermal load adaptability under cyclic heat exchange conditions. It is the recommended optimal configuration for the optimized design of the flow guiding structure parameters in this application.

[0108] Therefore, for reference Figure 14 As shown, Figure 14 This paper illustrates a flowchart of an integrated simulation analysis method for aluminum alloy heat pipe load-bearing and heat conduction, incorporating a VOF gas-liquid two-phase flow model, according to some embodiments of this application. This application designs an integrated simulation analysis method for aluminum alloy heat pipe load-bearing and heat conduction, incorporating a VOF gas-liquid two-phase flow model, including:

[0109] S1: Construct a VOF gas-liquid two-phase flow model and set up a set of governing equations that include momentum conservation, energy conservation, and mass conservation.

[0110] S2: Select multiple flow guiding unit styles and characterize and quantify the geometric feature parameters of multiple flow guiding unit styles, thereby simplifying the three-dimensional heat pipes of multiple flow guiding unit styles into multiple two-dimensional geometric models of heat pipes.

[0111] S3: Combine multiple heat pipe two-dimensional geometric models with VOF gas-liquid two-phase flow models for finite element simulation, construct multiple heat pipe finite element models with different flow guiding element styles, and extract the simulation output data of each heat pipe finite element model.

[0112] S4: The heat pipe performance evaluation function is established by weight allocation method. Based on the heat pipe performance evaluation function and simulation output data, the comprehensive heat pipe index of multiple flow guiding units is calculated, and then the optimal flow guiding unit pattern is generated.

[0113] S5: Perform multi-parameter finite element simulation on the optimal flow guiding unit style, construct a heat pipe finite element model with different flow guiding unit parameters, and then output the flow guiding unit parameters with the best performance.

[0114] The method for calculating the overall heat pipe performance of multiple flow guiding units includes:

[0115] S41: Collect the temperature distribution parameters of each temperature monitoring point set.

[0116] S42: For each temperature distribution parameter, assign a membership degree calculation formula based on the weighted analysis method:

[0117] ,in For the membership degree of the indicator, For normalized index values, This represents the i-th simulation group. This represents the j-th evaluation indicator. Indicates the first The minimum value of each evaluation indicator. Indicates the first The maximum value of each evaluation indicator.

[0118] S43: Calculate the overall score for temperature distribution characteristics: ,in This represents the overall score. These are the weighting coefficients.

[0119] S44: Calculate the average vertical displacement at the fluid front point: ,in This represents the average vertical displacement. Let t be the position of the gas phase front point in the t-th simulation analysis step. N is the total number of sampling simulation analysis steps.

[0120] In the calculation of the vertical average displacement of the fluid front point, the method further comprises:

[0121] S441: Construct a gas phase distribution threshold according to the volume fraction and screen out the gas phase region according to the gas phase distribution threshold.

[0122] In the VOF model simulation result, each grid cell has a gas volume fraction at the current time, usually in the range of [0, 1], in some embodiments of the present application, the gas phase distribution threshold can be set to be greater than 0.5, for example, the gas phase distribution threshold is taken as 0.7, so as to screen out the main gas phase region.

[0123] S442: Scan all grid cells in the gas phase region in the vertical direction.

[0124] S443: Extract the gas phase front region by using the maximum connected domain method.

[0125] In which, eight-neighborhood or four-neighborhood connected domain can be used to search all independent connected regions, then the maximum coordinate value in the vertical direction of each connected region is calculated, and then the connected region with the maximum vertical direction maximum coordinate value is selected from all connected regions, which is set as the gas phase front region at the current simulation time.

[0126] S444: Calculate the barycenter coordinates according to the geometric center coordinates of all grid cells in the gas phase front region.

[0127] S445: Take the barycenter coordinates as the position of the gas phase front point.

[0128] S45: Identify the fluid velocity distribution.

[0129] Therefore, referring to Figure 15 , as shown in Figure 15A module connection diagram of an aluminum alloy heat pipe bearing and heat conduction integrated simulation analysis system combined with a VOF gas-liquid two-phase flow model is shown. The application designs an aluminum alloy heat pipe bearing and heat conduction integrated simulation analysis system combined with a VOF gas-liquid two-phase flow model, which comprises: a two-phase model construction module 201 for constructing a VOF gas-liquid two-phase flow model and setting control equation groups containing momentum conservation, energy conservation and mass conservation; a two-dimensional model simplification module 202 for selecting a plurality of guide unit styles and characterizing and quantifying the geometric feature parameters of the plurality of guide unit styles, and then simplifying the three-dimensional heat pipes of the plurality of guide unit styles into a plurality of heat pipe two-dimensional geometric models; a finite element simulation module 203 for combining the plurality of heat pipe two-dimensional geometric models with the VOF gas-liquid two-phase flow model for finite element simulation, constructing a plurality of heat pipe finite element models with different guide unit styles and extracting simulation output data of each heat pipe finite element model; also for performing multi-parameter finite element simulation on the optimal guide unit style, constructing heat pipe finite element models with different guide unit parameters; an optimal design output module 204 for establishing a heat pipe performance evaluation function using a weight distribution method and calculating a heat pipe comprehensive index of a plurality of guide units according to the heat pipe performance evaluation function and the simulation output data, and then generating an optimal guide unit style; also for outputting guide unit parameters with the best performance.

[0130] In some embodiments, with reference to Figure 16 as shown, Figure 16 A connection diagram of an electronic device for implementing the embodiments of the application is shown. The electronic device 3 comprises a memory 301 and a processor 302, and the memory 301 stores a computer program executable on the processor 302. The processor 302 implements the method in the above embodiments when executing the computer program. The number of memories 301 and processors 302 can be one or more.

[0131] The electronic device 3 further comprises:

[0132] A communication interface 303 for communicating with external devices and performing data interaction transmission.

[0133] If the memory 301, the processor 302 and the communication interface 303 are independently implemented, the memory 301, the processor 302 and the communication interface 303 can be connected to each other through a bus and complete communication between them.

[0134] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 16 Only one thick line is used in the figure to represent the bus, but it does not mean that there is only one bus or only one type of bus.

[0135] Optionally, in a specific implementation, if the memory 301, the processor 302, and the communication interface 303 are integrated on a chip, the memory 301, the processor 302, and the communication interface 303 can complete communication with each other through an internal interface.

[0136] The embodiment of the present application provides a computer readable storage medium, which stores a computer program, and the program is executed by the processor 302 to implement the method provided in the embodiment of the present application.

[0137] The embodiment of the present application further provides a chip, which comprises the processor 302, is used for calling and running instructions stored in the memory 301 from the memory 301, so that a communication device installed with the chip executes the method provided in the embodiment of the present application.

[0138] The embodiment of the present application further provides a chip, which comprises an input interface, an output interface, a processor 302, and a memory 301, the input interface, the output interface, the processor 302, and the memory 301 are connected through an internal connection path, and the processor 302 is used for executing code in the memory 301, when the code is executed, the processor 302 is used for executing the method provided in the embodiment of the present application.

[0139] It is to be understood that the above-described processor 302 can be a central processing unit (CPU), but can also be other general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gates or transistor logic components, discrete hardware components, or the like. The general purpose processor can be a microprocessor or any conventional processor, or the like. It is to be noted that the processor 302 can be a processor supporting an advanced RISC machine (ARM) architecture.

[0140] Further, the above-described memory 301 can include read-only memory and random access memory, and can also include non-volatile random access memory. The memory 301 can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can include read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM) or flash memory. The volatile memory can include random access memory (RAM) used as an external cache. By way of example but not limitation, many forms of RAM are available. For example, static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM) and direct memory bus random access memory (Direct Rambus RAM, DRRAM).

[0141] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A simulation analysis method for integrated load-bearing and heat conduction of aluminum alloy heat pipes combining a VOF gas-liquid two-phase flow model, characterized in that, The method includes: A VOF gas-liquid two-phase flow model was constructed and a set of governing equations including momentum conservation, energy conservation, and mass conservation were set. Multiple flow guiding unit styles are selected and their geometric feature parameters are characterized and quantified, thereby simplifying the three-dimensional heat pipes of multiple flow guiding unit styles into multiple two-dimensional geometric models of heat pipes. Multiple heat pipe two-dimensional geometric models are combined with VOF gas-liquid two-phase flow model for finite element simulation. Multiple heat pipe finite element models with different flow guiding element styles are constructed and the simulation output data of each heat pipe finite element model are extracted. A heat pipe performance evaluation function is established using a weighted allocation method. Based on the heat pipe performance evaluation function and simulation output data, the comprehensive heat pipe index of multiple flow guiding units is calculated, thereby generating the optimal flow guiding unit pattern. Multi-parameter finite element simulations are performed on the optimal flow guiding unit style to construct heat pipe finite element models with different flow guiding unit parameters, and then the flow guiding unit parameters with the best performance are output.

2. The method according to claim 1, characterized in that, The method for constructing a VOF gas-liquid two-phase flow model includes: The gas-liquid interface changes in the VOF gas-liquid two-phase flow model are defined using a volume fraction equation: ,in The volume fraction is denoted by t, which has a value between 0 and 1; t is the time interval. For gradient operators, For fluid velocity; The density of both gas and liquid fluids was calculated using a volume fraction weighted average method. ,in For mixed bulk density, and The fluid density is given.

3. The method according to claim 2, characterized in that, When setting up the governing equations, the method includes: Based on Newton's second law and considering pressure gradient, gravity, viscosity, and the interaction between the two phases, the momentum equation for the gas phase is set up as follows: And setting the momentum equation for the liquid phase: ,in For gas phase density, For gas phase velocity, For fluid pressure, It is the acceleration due to gravity. For the stress tensor of the gas phase, It is the interaction force between the gas phase and the liquid phase. The density of the liquid phase is... For liquid phase velocity, For the stress tensor of the liquid phase; Set up the energy equation and volume fraction equation for the liquid phase heating and vaporization stages: , ,in Total energy per unit mass For the velocity of the fluid, Thermal conductivity, For temperature, This is the heat source term in the vaporization process, and it is related to the latent heat of vaporization of the condenser; The source term reflects the volume fraction of the liquid turning into a gas. Set up the energy equation and volume fraction equation for the gaseous rise and condensation stages: , ,in This is the heat source term in the condensation process, corresponding to the latent heat of condensation of the refrigerant; The source term reflects the volume fraction of the gas-to-liquid process; Set up the momentum equation and mass conservation equation for the liquid condensate dripping and flow stages: , ,in For fluid viscosity, This is the force caused by gravity.

4. The method according to claim 2 or 3, characterized in that, The selected flow guide unit pattern includes at least two of the following planar geometric shapes: annular fan shape, rectangle, square, triangle, ellipse, S-shape, circle, pencil shape, honeycomb shape, and regular polygon.

5. The method according to claim 4, characterized in that, The method, in characterizing and quantifying the geometric feature parameters of multiple flow guide unit patterns, includes: Define the cavity solid area ratio : ,in This represents the total area of ​​the internal cavity of the two-dimensional heat pipe. This refers to the total area occupied by the flow guiding unit inside the two-dimensional heat pipe. Define the sum of the side lengths of all flow guiding elements. : , This is the sum of the side lengths of a single flow guiding unit.

6. The method according to claim 5, characterized in that, The method for simplifying a three-dimensional heat pipe with multiple flow guide unit patterns into multiple two-dimensional geometric models of heat pipes includes: The equivalent plane projection method is used to convert the flow guiding unit in the three-dimensional heat pipe into a two-dimensional planar structure with equivalent flow guiding path length and channel cross-section; By controlling the geometric characteristic parameters of the flow guiding unit, the fluid channel path can be regulated to reflect the actual fluid distribution and flow behavior inside the heat pipe in a two-dimensional planar structure.

7. The method according to claim 2 or 6, characterized in that, The method for constructing a finite element model of a heat pipe includes: Define the heat pipe material; Define the type of filling fluid, the filling ratio, and the physical properties of the filling fluid; Set the solver type to pressure benchmark solver and the time to transient, and set the maximum number of iterations and the convergence criterion; The multiphase model for finite element simulation is set as a VOF gas-liquid two-phase flow model. Set thermal boundary conditions; Set the initial velocity, temperature, and gravity, and set the initial fluid distribution ratio of the heat pipe; The discretization scheme for the finite element simulation is set as follows: for flow, a second-order upwind difference is used; for energy, a standard difference is used.

8. The method according to claim 7, characterized in that, The method for calculating the overall performance of a heat pipe includes: Collect temperature distribution parameters from each set temperature monitoring point; For each temperature distribution parameter, a membership degree calculation formula is assigned according to the weighted analysis method: ,in For the membership degree of the indicator, For normalized index values, This represents the i-th simulation group. This represents the j-th evaluation indicator. Indicates the first The minimum value of each evaluation indicator. Indicates the first The maximum value of each evaluation indicator; Calculate the comprehensive score for temperature distribution characteristics: ,in This represents the overall score. These are the weighting coefficients; Calculate the vertical average displacement at the fluid front point: ,in This represents the average vertical displacement. Let t be the position of the gas phase front point in the t-th simulation analysis step. The coordinates of the initial evaporation starting point are given, and N represents the total number of sampling simulation analysis steps. Identify fluid velocity distribution.

9. The method according to claim 8, characterized in that, The method further includes, when calculating the average vertical displacement of the fluid front point: A gas phase distribution threshold is constructed based on the volume fraction, and gas phase regions are screened out based on the gas phase distribution threshold. All grid cells in the gas phase region are scanned vertically; The gas-phase front region is extracted using the maximum connected component method; The centroid coordinates are calculated based on the geometric center coordinates of all grid cells in the gas-phase leading edge region. The centroid coordinates are used as the location of the gas phase front.

10. A simulation analysis system for integrated load-bearing and heat conduction of aluminum alloy heat pipes using a VOF gas-liquid two-phase flow model based on the method according to any one of claims 1-9, characterized in that, The method includes: The two-phase model construction module is used to construct a VOF gas-liquid two-phase flow model and set up a set of governing equations that include momentum conservation, energy conservation, and mass conservation. The two-dimensional model simplification module is used to select multiple flow guide unit styles and characterize and quantify the geometric feature parameters of multiple flow guide unit styles, thereby simplifying the three-dimensional heat pipes of multiple flow guide unit styles into multiple two-dimensional geometric models of heat pipes. The finite element simulation module is used to combine multiple heat pipe two-dimensional geometric models with VOF gas-liquid two-phase flow models for finite element simulation, construct multiple heat pipe finite element models with different flow guiding unit styles, and extract the simulation output data of each heat pipe finite element model; it is also used to perform multi-parameter finite element simulation on the optimal flow guiding unit style, and construct heat pipe finite element models with different flow guiding unit parameters. The optimized design output module is used to establish a heat pipe performance evaluation function using a weighted allocation method, and to calculate the comprehensive heat pipe index of multiple flow guiding units based on the heat pipe performance evaluation function and simulation output data, thereby generating the optimal flow guiding unit style; it is also used to output the parameters of the flow guiding unit with the best performance.

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