Research On Simulation And Experiment Of Flow Boiling Heat Transfer Characteristics Of Microchannel Cold Plate

With the increasing integration of phased array radar,traditional cooling technologies can no longer meet the requirements of limited space and efficient heat dissipation,exploring new and efficient cooling methods is an urgen problem to be solved.Microchannel flow boiling heat transfer is a research hotspot of phased array antenna thermal control methods because of its small size and obvious heat transfer performance.In the microchannel flow boiling heat transfer process,the flow stability and heat transfer reliability due to bubble behavior are more complicated.In order to further deepen the research of heat transfer characteristics of the two-phase flow and make up for the shortage of experiment research of microchannel cold plate radiator at present stage,the main contents of this paper are as follows:(1)Research on simulation method of flow and boiling heat transfer process of rectangular microchannel.Based on the in-depth analysis of multiphase flow models and heat and mass transfer model,a simulation method for microchannel flow boiling heat transfer process is proposed,and taking a single rectangular horizontal microchannel as the research object for two-phase flow simulation.The effects of the bubble behavior(dynamic behavior such as detachment and coalescence)and flow pattern evolution(bubble flow,slug flow and stretch bubble flow)on the microchannel pressure drop and heat dissipation characteristics are analyzed,the laws of pressure drop and heat transfer characteristics of microchannel during two-phase flow are obtained.(2)Research on the orthogonal test and two-phase flow experiment of microchannel cold plate heat dissipation characteristics.In view of the shortcomings of existing experimental schemes,this paper designs an orthogonal test scheme for liquid cooling cold plate.The maximum temperature and temperature uniformity of 32 and 128 array cold plates are used as indicators;the methods of max-min difference and variance analysis are used to distinguish the primary and secondary order and significance level of each factor(inlet temperature,inlet flow rate and heat flow density).In order to explore the true heat dissipation characteristics of the cold plate in the flow boiling state,this paper desigs a two-phase flow experimental scheme,and constructs a steady-state numerical method for the three-dimensional microchannel cold plate flow boiling heat transfer process with complex topology,the simulation results are well matched with the two-phase flow experiment results,and the maximum error is less than 10%.(3)Research on the experimental and numerical simulation for heat dissipation characteristics of microchannel cold plates under random vibration.Vibration is one of the main environmental factors for product failure.In order to ensure that the cold plate can work normally under random vibration condition,this paper designs a cold plate random vibration experimental scheme,builds a vibration experimental platform and develops the vibration experiment steps for random vibration test.Based on the analysis of vibration experiment results,the heat dissipation characteristics of the microchannel cold plate under random vibration state are obtained.At the same time,based on MATLAB software and ANSYS Workbench platform,the temperature field and flow field of the three-dimensional cold plate model under random vibration state are simulated by thermal-flow-solid bidirectional coupling method,and the simulation results are well explained and verified the experimental conclusion.