周期性矩形槽通道内对流换热的振荡

采用非稳态数学模型,通过数值模拟对周期性矩型槽通道内流动和换热的振荡特性进行了研究。结果表明:随着Re的增大,对流换热从入口后某一个几何周期开始振荡,振幅沿着通道逐渐增加,并经过若干周期后振幅基本不变;对于不同的Re开始振荡的几何周期数不同;当振幅基本不变时,各几何周期的平均Nu及相应点的速度按时间的平均值基本相等,表明振荡的流动和换热特征参数的时均值仍然具有周期性充分发展的特征;通道中突出物高度对振荡有显著影响,突出部分越高,开始振荡的几何周期数越小。

THE OSCILLATION OF THE CONVECTION HEAT TRANSFER IN PERIODICAL CHANNELS WITH PERIODICALLY GROOVED PARTS

Based on an unsteady model, the oscillatory convection heat transfer is studied numerically in the periodical channels with periodically grooved parts. It is found that when the Re is increasing, the convection heat transfer begins to oscillate at some module after the entrance and the swing increases gradually along the channel, and after several modules the swing will not change any more. The number of module in which the oscillation begins depends on the Re. When the swing is constant the time-average values of average Nu and the velocities of the relevant point in each module are almost same respectively, which shows the periodically fully developed character for the convection heat transfer. The numerical results also show that the height of the rectangular protrusive parts influences the oscillation.