Research On Equivalent Modeling Method Of Heat Flow Characteristics Of Microchannel Of Phased Array Antenna And Thermal Design

With the improvement of integration of phased array antenna,the thermal control problem of antenna arrays has been paid much attention.The microchannel cold plate is one of the effective ways to solve the high heat dissipation problem of it.However,a large number of high-density and micro-scale grids are gathered in the cold plate because of the cross-scale modeling of the microchannel,as a result,computational efficiency is reduced and numerical simulation difficulty is increased.In order to decrease the complexity of the numerical simulation of the microchannel,some main research contents are illustrated as follows:(1)Study on the equivalent modeling method of the microchannel.An equivalent modeling of the microchannel is constructed,which reduces the number of grids and improves the computational efficiency by ignoring the topology structure of the original model.The thermal resistance and flow resistance fitting calculation formula of the microchannel are deduced,and the influence factors of the thermal parameters are obtained.In the process of equivalent modeling,the fluid velocity of the model is considered,and the thermal parameters of the original model are corrected,then the calculation method of the equivalent model thermal parameters is received.(2)Study on the analysis of thermal and flow characteristics in microchannel.The thermal parameters and equivalent calculation accuracy of the heat sink and the topology structure of microchannel are analyzed respectively.The thermal parameters of the heat sink are calculated by theoretical analysis,numerical simulation and equivalent modeling,and the results show that the thermal resistance and flow resistance fitting formula derivate in this paper are in good agreement with other analysis results and the equivalent accuracy is favorable.Also the results of the equivalent analysis of the microchannel topology structure indicate that the method has a strong applicability.In addition,the influence of the spreading resistance and the combination way of equivalent model on the equivalent calculation accuracy is calculated,which establishes the foundation for the equivalent analysis of the antenna arrays.(3)Study on the thermal analysis and thermal design of phased array antenna.The thermal simulation method of the antenna arrays is studied,and a segmented flow structure of the array is designed for the conformal phased array antenna.The numerical results of temperature and pressure generated by tree-like and flat-like microchannel topology structure in the optimized array are compared and analyzed.Also the equivalent method of microchannel is applied to the thermal analysis of the antenna array,and the results show that this method can greatly reduce the cost of the numerical calculation,improve the quality of the grids,and the equivalent calculation error will not affect the relative heat dissipation performance and the pressure drop of the antenna arrays,when the number of grids for numerical calculation is reduced drastically.(4)Study on the numerical and experimental verification of thermal control cold plate.The equivalent modeling method is applied to the cold plate thermal analysis,and the experimental results of the thermal performance of the cold plate are compared with the results of the numerical analysis of the original and equivalent model.Then the validity and reliability of the proposed method are verified,because the simulation results are close to the experimental data.