中文摘要：

本文采用数值模拟和实验研究的方法对高频脉冲管制冷机的重力特性进行了对比研究。研究表明，冷指方向与重力方向的夹角变化会对脉冲管制冷机的性能产生较大的影响，在135°时脉冲管内部会形成环流，在较低的输入功率下甚至不能达到其要求的温区。提高脉冲管制冷机的输入功率（脉冲管内动压幅值）、减小脉冲管的特征长度以及减小惯性管的长度在一定程度上可以抑制重力的消极影响。

英文摘要：

A comparison investigation of gravity effect in high-frequency pulse tube cryocoolers was carried out by CFD simulation and experiments. The results show that the performance of coolers is influenced significantly by gravity inclination angle. There will be formed circle flow in pulse tube when inclination angle is more than 135° and the cooler can not gain the required temperature for small input power. Increasing the input power, decreasing the characteristic dimension of pulse tube and decreasing the length of inertance tube can reduce the influence of gravity effect in high frequency pulse tube crycooler to a certain extent.