Driving mechanism of thermal transpiration pump with porous material
Driving mechanism of thermal transpiration pump with porous material
复制标题
DOI：
10.1063/5.0023403
复制
发表时间：
2020-10-01
期刊：
影响因子：
1.6
通讯作者：
Sugimoto, Hiroshi
中科院分区：
文献类型：
--
作者：
Sugimoto, Shogo;Sugimoto, Hiroshi
采用直接模拟蒙特卡罗方法对多孔材料热蒸腾泵中稀薄气体的行为进行了数值研究。对泵实现的质量通量进行了各种努森数和孔长与孔径比的分析。结果表明，孔末端周围的热边缘流动在确定最大性能方面起着至关重要的作用。热边缘流的影响导致驱动机制与努森的类似热蒸腾泵有质的差异。当孔长度远大于孔径时，质量流量在努森数相当大时取最大值。数值试验表明，当抑制边缘流时，可以获得更大的质量通量。研究了多个适应系数值和复杂孔隙几何形状的质量通量。目前的结果表明，只有后者会导致质量通量的减少。还针对几种情况分析了压缩比，包括泵的性能曲线。结果表明，较小的调节系数会降低泵的压缩比。
The behavior of the rarefied gas in the thermal transpiration pump with the porous material is investigated numerically by the direct simulation Monte Carlo method. The mass flux achieved by the pump is analyzed for a wide range of Knudsen numbers and ratios of the pore length to the pore diameter. The results show that the thermal edge flows around the ends of the pore play an essential role in determining the maximum performance. The effect of the thermal edge flow leads to a qualitative difference in the driving mechanism from a similar thermal transpiration pump by Knudsen. The mass flow takes a maximum value at a considerably large Knudsen number when the pore length is much larger than the pore diameter. The numerical tests show that a larger mass flux is possible when the edge flow is suppressed. The mass flux is investigated for several values of accommodation coefficient and complex pore geometries. The present results show that only the latter leads to the reduction in the mass flux. The compression ratio, including the performance curve of the pump, is also analyzed for several cases. The results show that the small accommodation coefficient decreases the compression ratio of the pump.