【作者】 王迎昆；

【导师】 贾建援；

【作者基本信息】 西安电子科技大学 ， 机械电子工程， 2008， 硕士

【摘要】 本文基于微流体和微传热学的机理,针对具有滑流边界和温度跳变效应的微缝隙通道对流换热方程,得到不同于宏观传热学的速度场和温度场的解析解,并得到努塞尔数和温度跳变长度新的表达式。提出考虑轴向热传导影响的新的对流换热实验关联式,通过对实验数据处理并与经典实验关联式相比较,结果表明两实验关联式求得的努塞尔数相差不大,说明两者用于微通道对流换热实验不会造成显著误差。设计了高密度组装微通道实验装置并进行换热实验,实验结果表明,利用微传热实验关联式处理的实验数据得到的努塞尔数小于宏观经典理论值,但在微传热学理论意义上,引入滑移长度可以表征壁面形貌特征,可使得实验得到的努塞尔数与微传热理论得到的努塞尔数基本相同,因此对微通道设计只能依据微传热学理论,而宏观经典理论不能用于微通道设计。实验研究表明:高密度组装微通道换热器具有尺寸小、换热能力强的优点,本文所给出的微传热理论正确合理,适用于电子芯片的高密度组装设计及其网络换热器的工程设计。更多还原

【Abstract】 Based on the mechanisms of microfluidics and micro heat transfer theories, the analytical resolutions of velocity filed and temperature filed were obtained for the convective heat transfer equation of microchannel(slot) considering the boundary conditions of velocity slip and temperature jump. And the new expression of Nusselt number and coefficient of temperature jump were obtained.The correlations of the convection heat transfer were obtained combining with the boundary condition of axial wall heat conduction. Then compared with the classical heat transfer correlations by processing the experimental data, the experimental results certify that the two results of Nusselt number has little difference. It is shown that both of heat transfer correlations can be used in the experiment of convective heat transfer of microchannel.The experimental equipment of high-density assembly was established, the experiment was actualize. Experiment results suggest that the Nusselt number obtained by using the micro heat transfer correlations is significantly less than classical value. But in the micro heat transfer theory sense, the Nusselt number derived from experiment with considering the coefficient of velocity slip which expressed wall characteristic is more approach to the classical one. It is shown that the design of microchannel can only be based on the theories of micro heat transfer and the classical theory can not be used to microchannel design.It is shown that the high-density assembly microchannel heat exchanger has many advantages, such as small size, high heat transfer performance. The given theory can be used for the design of high-density assembly for computer chips and microchannel network heat exchanger.更多还原