稀薄氣平面Poiseuille流動之蒙地卡羅直接模擬

DSMC of Plane Poiseuille Flow for a Dilute Gas

曾培元(P. Y. Tzeng) ； 羅仲禹(C. Y. Lo) ； 宋齊有(C. Y. Soong)

《中國航空太空學會學刊》 34卷4期 (2002/12) Pp. 371-378

https://doi.org/10.6124/TAASRC.200212_34(4).10

摘要

本文利用直接模擬蒙地卡羅法(DSMC)探討稀薄氣體於平面Poiseuille流中，當流動條件在連體流、滑動流及低過渡流區並維持在層流及次音速流的狀態下，Knudsen數(Kn)對速度、溫度等流動性質的影響。流體流動之驅動力爲一固定的加速度場，藉此加速度所形成之超距力場來等效一般作用於此流動之壓力梯度，上下兩側的邊界維持等溫，在固定分子數量密度的情形下，可藉由上下邊界間距的改變以達到Kn數的變化。
本文使用可變硬球分子模式(VHS Model)取代以往之硬球分子模式(HS Model)，模擬的結果顯示兩者在定性上具有一致性，但在定量上仍有差異，且在溫度分佈上皆與流體動力方程式所預測的結果不同。

關鍵字

直接模擬蒙地卡羅法中DSMC ； 平面Poiseuille流動 ； Boltzmann方程式

並列摘要

Direct Simulation Monte-Carlo (DSMC) with variable hard sphere (VHS) model for a dilute gas undergoing plane Poiseuille flow is presented. The flow is constrained to two parallel plates at constant temperature, and a constant acceleration field is applied to the system to restrict the flow in laminar and subsonic state. The simulation results show that the discrepancies of hydrodynamic prediction are widening as indicated from velocity and temperature profiles when the flow in continuum regime transfers to slip flow regime, then low transition regime by increasing Knudsen number (Kn).
The data predicted by VHS model differ quantitatively from hard sphere (HS) model, but it exists qualitative consistency between them Modified hydrodynamic equation based on VHS model gives better results for continuum and slip flow regime.

並列關鍵字

DSMC ； Plane Poiseuille flow ； Boltzmann equation