摘要
利用降压地面模拟技术,可以抑制自然对流的影响,从而通过地面试验结果还原空间密封舱内的流动换热情况。降压法的关键在于确定临界压力,使得自然对流对流动换热的影响刚好得到忽略。本文使用数值模拟方法确定临界压力比,以方腔密封舱内的流动换热情况为例,计算了不同Gr/Re^2数和压力比下密封舱内的流动换热情况。得到了舱内气体温度分布和对流换热系数。通过比较空间情况和地面情况的计算结果,分析了自然对流给流动换热带来的影响,给出了判断临界压力的准则式,并给出了临界Gr/Re^2数。
To study the convection heat transfer in spacecraft cabins, the lowering pressure method is usually used to suppress the effect of natural convection in terrestrial experiments. The key of lowering pressure method is to quantify a critical pressure, assuring the effect of natural convection on convection heat transfer, is exactly suppressed. In the present work, the convection heat transfer in a cubical cabin is studied numerically under various Gr/Re2 and various pressures, both in space condition and terrestrial conditions. The heat transfer coefficient and temperature distribution are obtained. Results are compared between in space condition and in terrestrial condition. The effect of pressure on suppressing the natural convection is analyzed quantitatively. The criterion formula is obtained for calculating the critical pressure in the lowering pressure method. The criterion formula for calculating the critical Gr/Re^2 is also obtained.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2009年第12期2119-2121,共3页
Journal of Engineering Thermophysics
关键词
地面降压模拟
自然对流
临界压力
准则式
lowering pressure method
natural convection
critical pressure
correlation
