Research On Topology Optimization And Thermal Analysis With Phase Change Process Based On Meshless Method

Due to its complexity and variability,the phase change heat transfer problem has always been a hot research topic,while the phase change heat transfer analysis and structural optimization design of composite materials are more theoretical and practical research topics.As a moving boundary problem,the numerical calculation method of grid class needs to continuously reconstruct the grid.Meshless method only needs node information,which has significant advantages in tracking dynamic phase interface.Grid dependency and grid squares can be effectively avoided in the subsequent topology optimization design.In this paper,the phase change heat transfer analysis of anisotropic material is studied based on the element-free Galerkin(EFG)method.The topological optimization of anisotropic material with phase change process is carried out.The main research contents are summarized as follows:(1)Based on the theory of numerical heat transfer,a meshless heat transfer calculation model of anisotropic material with phase change process was established,and relevant calculation programs were written.The validity of the model was verified by a classical example of phase change heat transfer,and the influence of the phase change temperature interval and time step on the calculation accuracy was discussed.The effects of anisotropic thermal conductivity factor and off-angle on material performance and phase change process were discussed.Compared with FEM results,the advantages of EFG method in calculation accuracy and dynamic phase interface tracking were shown.(2)A meshless phase change heat transfer calculation model of anisotropic material with moving heat source was established.The correctness of the calculation model was verified by practical engineering problems.The effects of anisotropic thermal conductivity factor and off-angle on the temperature field and molten pool shape during the phase change heat transfer were studied.The influence of the intensity and velocity of the moving heat source on the phase change heat transfer process was discussed.The reasonable range of the above parameters were given.(3)Based on the meshless EFG method and the variable density method,with the node density as the design variable and the time integral of the global transient heat dissipation as the objective function,a meshless method topological optimization calculation model for anisotropic material structure with phase change process was established.Compared with the results obtained by FEM,the correctness of the topology optimization model was verified.The effects of anisotropic thermal conductivity factor and off-angle on the topological results were discussed.The meshless phase change heat transfer analysis was carried out before and after the topological optimization,and the phase change heat transfer process before and after the optimization was compared.In this paper,based on the meshless method,heat transfer analysis and topology optimization design of anisotropic material with phase change heat transfer were studied.And the established model was applied to practical engineering problems,which has a good calculation accuracy.At the same time,the effectiveness of topology optimization method in engineering problems was proved.This study has certain theoretical and practical significance.