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四边形阵列的微通道型Knudsen泵内热驱流动的DSMC数值模拟优化

Numerical Simulation Optimization via DSMC Method for Thermally Induced Flow in Microchannel-Type Knudsen Pumps with Quadrilateral Arrays

  • 摘要: Knudsen泵是可应用于微机电系统(MEMS)的一种微型气体输送装置。本文提出一种带有不同温度四边形的微通道构型,通过直接模拟蒙特卡罗(DSMC)方法对该微通道内气体流动特性进行了数值模拟研究,并针对其气体泵送特性进行了优化研究,给出了泵送气体的最佳参数。研究发现,微通道内温差在75~1200 K范围内时,质量流量随着温差的升高几乎呈线性增大,且温差在1200 K时质量流量是75 K时的10倍。对于不同的 Knudsen数,最大气体流速和质量流量均出现在 Kn = 0.3 时,说明在过渡流态微通道的气体泵送能力最强。另外,相同工况下该微通道的无量纲质量流量是传统矩形 Knudsen泵的62倍。这些结论可为工业领域内各种微型气体泵送装置的实现和设计提供参考依据。

     

    Abstract: A microchannel geometry with different temperature quadrilaterals is proposed, and its pumping capacity is demonstrated, giving its optimal parameters for pumping gas. Numerical simulations of the microchannel are performed using the direct simulation Monte Carlo (DSMC) method. The results show that the mass flow rate of the microchannel increased almost linearly with the temperature difference in the range of 75 to 1200 K. The mass flow rate at a temperature difference of 1200 K is 10 times higher than that at a temperature difference of 75 K. Both the maximum gas flow rate and mass flow rate occur at Kn = 0.3, indicating that the gas pumping capacity is strongest in transitional flow. Also, the dimensionless mass flow rate of this microchannel at the same operating conditions is 62 times higher than that of a conventional rectangular Knudsen pump.

     

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