The Airborne Electronic System Heat Simulation Analysis And Optimization Design

With the development of electronic technology, the function of electronic devices is becoming more and more powerful. The heat flux density is becoming more and more heavy along with the higher integration of the chip and smaller volume. When the temperature of the operated environment of the electronic system increases by ten degree Celsius, the failure rate of the equipment will increase by almost one order of magnitude. The heat dissipation performance is related to the stability and life of the equipment. Therefore, reasonable thermal structure design of electronic equipment is the key to improve the reliability of the equipment.In this paper, the study is related to the airborne sealed electronic system whose internal chassis is completely sealed. The internal temperature is mainly transmitted to the outside of the enclosure by The way of heat conduction and then heat is emitted into the surrounding environment through the radiator. On the basis of heat transfer and gas dynamics, the cooling structure of the chassis is designed and optimized to improve the cooling performance of the system. The main contents of this paper include the following aspects:(1) Based on FLOTHERM thermal simulation software, the virtual model is built up and the simulation results of the model are analyzed. Finally, the performance of electronic equipment is verified by the test of the high temperature and humidity test box.(2) Through theoretical calculation and analysis of the heat sink of the chassis, the objective function and the variables that need to be optimized are determined. Based on the basic principle of the composite optimization algorithm, the number and height of the fins are optimized and the peak temperature of the chassis is reduced by 7.6%. The optimization results are verified by experiments and the experimental results prove the validity and feasibility of the optimized structure.(3) Through the analysis of the simulation results of the electronic device, the heat generated by the power module and the calculation process modules have the closest relationship with the whole system. Based on the principles of experimental design to optimize components location on PCB for getting the chip layout rules, this study will provide a reference for the designer to design the layout of the components.(4) The area needs to be improved where system temperature is relatively concentrated. The upper and lower cover plate of the chassis is designed with wind channel structure. Firstly, the length of the air duct and the number of air duct are optimized by using the Center Command module of FLOTHERM. Secondly, the sudden expansion structure of the wind channel is improved. Finally, through theoretical analysis and calculation, the local energy loss of the improved structure is less. Through the simulation analysis for the air pressure and velocity in the air duct, the correctness of the calculation results is verified. The flow velocity and the pressure of air flow in the air duct is got. The optimized structure is conducive to the flow of air, which will improve the cooling efficiency of the chassis.The contents of this paper are practical, which can provide a reference for the design of the prototype structure and can short research cycle of electronic products.