Optimal Design Of Cooling Flow Channels Based On Fluid-Solid Conjugate Heat Transfer

The heat transfer structure is generally designed through thermodynamic calculations or engineering experience,but the disadvantage is that different topological forms have different heat dissipation effects.There are limitations to the heat dissipation design of complex structures,so how to design the best heat dissipation structure is an important subject.On the one hand,heat transfer structure heat dissipation design uses topology optimization design to reasonably distribute high thermal conductivity materials to achieve the purpose of heat dissipation,reduce the amount of materials used,and reduce costs;on the other hand,convection heat transfer can be used to design cooling channels and flow through fluids efficient heat exchange to take away heat.The cooling fluid in the flow channel of the material directly contacts the solid material,and the heat of the solid material is taken away by the fluid flow,which is called conjugate heat transfer.The topology optimization of the fluid-solid conjugate heat transfer structure is an effective method to improve the heat dissipation efficiency and realize the lightweight structure.With the improvement of theoretical level and computer computing efficiency,the optimization of fluid-solid conjugate heat transfer has attracted the attention of many scientific researchers and engineers.In the fluid-solid conjugate heat transfer structure,the heat transfer effect depends not only on the thermal properties of the fluid and solid materials in the flow channel,but also on the flow characteristics such as the shape of the flow channel and the flow rate.Therefore,it is necessary to design flow channels according to different fluid flow modes(laminar flow,turbulent flow)and different fluid-solid material properties to achieve corresponding effects is necessary.Based on the variable density method,this paper takes the average temperature and the minimum average temperature gradient as the optimization goal for different heat source forms,and optimizes the design of the solid material heat dissipation structure;The variable density method is introduced into the fluid topology optimization,and the energy consumption of the laminar fluid described by the NS equation.The minimum dissipation is the optimization goal to realize the flow channel design;Based on the laminar conjugate heat transfer,the Brinkman model is introduced to realize the optimal design of the N-S flow channel for different inlet velocities and volume fractions;Finally,in order to further design the complex flow channel and improve the cooling effect,the Darcy flow conjugate heat transfer model is introduced,and the feasibility of approximate replacement of the complex turbulence model for heat transfer optimization is verified.Besides,the darcy flow conjugate heat transfer model is used to optimize the flow channel topology,and flow channel structures with more divergent branches and good heat dissipation performance are obtained.Extracting the optimized flow channel structures,and establishing a direct flow channel with the same volume fraction,calculate the flow field and temperature field under the same load cases.The results show that the optimized flow channel has better cooling effect,and the flow loss is smaller.