The Numerical Investigation Of Air Impinging Cooling On A Fin Surface

The cooling technology that use air as the medium of transporting heat is investigated, taking the heat dissipation of microelectronic chip as the background, abstracting it as the efficient cooling problem of a surface. An original method of dissipating heat is provided, which uses the air impinging technology combined with the fin heat sink instead of the conventional fan cooling technology. It not only could produce high heat transfer coefficient in local area by air impinging, but also could eliminate the nonuniformity of heat flux and temperature field in the whole surface by fin heat sink. The air impinging could produce high nonuniform heat flux field in the whole surface, which is easy to be destroyed due to the high local temperature. And the thermal stress which also result from the nonuniform, will lead to descend of the heat dissipation efficiency and reliability. It can't work regularly at last.Mathematical and geometrical model is built by analyzing the physical phenomenon of heat dissipation on a high-density power component. Feasibility of the new-style cooling method is improved by numerical analysis. The structures of nozzles and fin heat sink are optimized by CFD; it could achieve the optimum by holding the air mass flow flux and other parameters. The factors influencing the heat dissipation efficiency is confirmed by analyzing the flow and temperature field in all kinds of working conditions. Considering the nozzles, the main factors are size of nozzles, velocity of impinging, and the arranging type; considering the fin heat sink, they are the length and width of fin, these primary parameters will be confirmed by computing.In the end, several types of heat sinks are provided, that the heights of fins are designed by some functions, e.g. the V, parabola and ellipse type. It is proved that the efficiency of V tape is the best by analyzing the heat dissipation of the three kinds of heat sinks. Then the wavy heat sink formed with the combination of the linear ones is provided, whose performance of heat dissipation is better than the conventional one, and can also save the raw material in the same working conditions.