多孔介质内交变流动与换热的格子Boltzmann研究

Simulation of Oscillating Flow and Heat Transfer in Porous Medium by Lattice Boltzmann Method

针对制约脉冲管制冷机效率提高的蓄冷器内交变流动与换热问题,本文使用格子Boltzmann方法计算并分析了多孔介质内交变流动与换热特性。结果表明,交变流动压力波振幅对速度与压力和温度间的相位差的影响很小;通道界面处速度与压力的相位差在某一孔隙率下有一极小值;多孔介质内最大阻力系数与雷诺数的关系可以为设计蓄冷器时填料结构的选择提供技术指导。

The lattice Boltzmann method is applied to investigate the oscillating flow and heat transfer in the regenerator, which is the limit of the efficiency enhancement for pulse tube cryocooler. The numerical simulation is presented for the characteristics of the oscillatory motion and heat transfer in the porous medium. The results indicate that the amplitude of the oscillating pressure wave has little influences for the phase differences among velocity, pressure and temperature. In the channel profile, there is a minimum value for the phase difference of velocity and pressure at one porosity. Moreover, the relationship of Reynolds number and the maximum drag coefficient will be the technical guide for the choice of refrigerator packing.