Study On The Heat Transfer Enhancement Effect Of Complex Configuration On Small Electronic Devices

Today,with the rapid development of science and technology,the development direction of electronic equipment tends to be integrated,high performance and miniaturization.The consequence of this trend is that heat dissipation becomes more difficult.Seeking reasonable and effective heat dissipation design is the key to solve this problem.In this paper,the finite volume method(FVM)with QUICK difference scheme is used to simulate the natural convection heat dissipation process in a closed space with complex configurations.The simulation results are validated by noncontact laser holographic interferometry and micro-flue gas tracer visualization,which lays a theoretical foundation for heat dissipation design of electronic devices.The main research contents are as follows:(1)The finite volume method(FVM)with QUICK difference scheme is used to establish physical and mathematical models for the heat transfer process of typical thermal system configurations,and to improve the numerical processing technology and calculation method.The additional source term method is used to deal with the natural convection heat transfer problem on the basic upper wind difference.(2)The change trend of air flow and heat transfer in bottom heating space with Rayleigh number is studied.The results show that the heat transfer effect increases with the increase of Rayleigh number,but there is a situation that thechange of air state affects the heat transfer.The influence of the height of heat source and the distance between heat sources on the air flow and heat transfer in the cavity due to the temperature difference between discrete heat sources is also discussed.The results show that the increase of heat source height and spacing has a positive effect on the flow and heat transfer.The three-dimensional characteristics of the problem are analyzed,and it is concluded that the threedimensional problem can not be replaced by the two-dimensional model.(3)When the two heat sources have a certain angle with the long axis and the two heat sources have the same temperature,the effect of flow and heat transfer decreases with the increase of the cavity size,and the angle has little effect on it.The influence of heat source spacing on heat transfer is different from that of the optimum condition without angle.The influence of heat source height on heat transfer is the same as that of the optimum condition without angle.The heat transfer effects of two discrete heat sources at different temperatures are qualitatively analyzed.(4)The two discrete heat sources have different sizes,including constant length-width ratio and constant heat source height.When the temperature of two discrete heat sources is the same,the average Nu number on the top surface is proportional to the temperature difference on the high and low temperature wall,but inversely proportional to the size of the cavity space structure.The heat transfer effect first increases and then decreases with the increase of heat source spacing.When the temperatures of the two discrete heat sources are different,theheat transfer of the above two conditions is better at the temperature difference of30℃ and 40℃.In this paper,the above four aspects are studied to provide a theoretical basis for heat transfer enhancement of small electronic equipment with complex configuration.