| The antenna array of vehicular active phased array radar which contains a large number of T/R module with large scale and high integration,will generate a lot of heat in the limited space when it works.Therefore,appropriate heat dissipation measures are needed to reduce the maximum temperature of the antenna chip,so as to ensure the stable and reliable operation of the phased array radar.Liquid cooling is an effective way of heat dissipation,and the proper design of the structure of liquid cooling plate can improve its heat dissipation performance.In this paper,a structure of the liquid cooling plate with sectional turnover combination considering the pressure drop performance of the liquid cooling plate is designed in order to reduce the maximum temperature in the designated area of the liquid cooling plate.And its heat dissipation performance is analyzed.Main works are organized as follows:(1)Firstly,the problem of channels design for liquid cooling plate is presented,which considers the condition of one side heat source and minimizing the maximum temperature of heat source region.Secondly,the numerical simulation analysis method for the heat dissipation performance(including pressure drop,regional maximum temperature,temperature uniformity and other indicators)of the liquid cooling plate is introduced,which includes the governing equation,boundary conditions,mesh generation requirements,etc.Finally,the liquid cooling plate with uniform straight channel is used as the initial design model,and the heat dissipation performance is analyzed by numerical simulation.The numerical results show that: for the liquid cooling plate with uniform straight channel,the temperature of the heat source distribution area increases gradually along the flow direction,and the maximum temperature reaches 450.67 K,exceeding the expected design index(358.15K).The reason is that as the thermal boundary layer becomes thicker along the flow direction,the heat dissipation performance of the liquid cooling plate decreases.Therefore,it is necessary to design the channel of the liquid cooling plate so that the cooling medium can be reasonably disturbed,divided and converged to improve the heat dissipation performance of the liquid cooling plate.(2)A design method of liquid cooling plate channel based on sectional turnover combination strategy is proposed.The basic idea is as follows.The gradient design is carried out on the channel section of the liquid cooling plate with uniform straight channel,and the density of the channel section along the normal direction of the unilateral heat source area is adjusted.According to the reasonable size of the straight channel liquid cooling plate along the direction of the channel,the "section-turnover-combination" is carried out to form the section turnover combination liquid cooling plate,and the structural size of each section of the liquid cooling plate is designed in order to divide and converge the cooling medium at the appropriate position without significantly increasing the complexity of the structure of the liquid cooling plate.The influence of the number of segments on the heat dissipation performance of the liquid cooling plate is studied.Starting from the structure design of the two-stage flip combined liquid cooling plate,the influence of the length of the segmented liquid cooling plate on the heat dissipation performance is analyzed by means of parameter analysis,and the design scheme of the two-stage flip combined liquid cooling plate with optimized size is obtained.The results show that the maximum temperature of the heat source region decreases to 371.19 K compared with the liquid cooling plate with uniform straight channel,which proves the effectiveness of the proposed design strategy;In addition,in order to increase the design freedom of the sectional turnover combination strategy,the three section turnover combination liquid cooling plate structure is obtained through the size optimization design.The results show that the heat dissipation performance of two kinds of sectional turnover combined liquid cooling plate is close,but the pressure drop of three section turnover combined liquid cooling plate is lower.(3)The structure of sectional turnover combined liquid cooling plate with fins is designed.In order to further improve the heat dissipation performance of the liquid cooling plate,fins are added into the channel of the designed three section turnover combined liquid cooling plate to enhance the heat dissipation performance of the channel by strengthening the coolant disturbance.The influence of different fin inclination angle,hydraulic diameter of channel and length of each section of liquid cooling plate on heat dissipation performance is analyzed.A sectional turnover combined liquid cooling plate structure with fins is designed and the maximum temperature of heat source area drops to 355.74 K,which meets the expected design index.In addition,it is found that the design strategy of sectional turnover combination is still effective after adding fins into the channel of liquid cooling plate through the comparative research.And the influence of fins in the channel on the heat dissipation performance of the three section turnover combined liquid cooling plate is analyzed.The results show that the cooling medium is fully disturbed in the flow process due to the existence of fins,so that the heat dissipation performance of the liquid cooling plate is improved. |
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