微直通道内气体滑移流动的二维理论和数值研究

以微直通道内气体滑移流动为例,采用扰动分析方法,结合不同阶滑移条件,得出N-S方程的理论解.采用不同滑移模型,对不同进出口压比、长宽比、工质的微通道流进行理论和数值分析,着重研究稀薄效应、热蠕动效应以及不同滑移条件对计算结果的影响.计算表明,努森数是表征稀薄效应的特征参数,而热蠕动效应的强弱依赖于雷诺数.在极大长宽比的低速流工况下,理论和数值结果与实验吻合很好.

Two-dimensional Theoretical and Numerical Investigation of Gaseous Slip Flows in a Micro-channel

In a perturbation analysis, a two-dimenslonal theoretical solution based on Navier-Stokes equations is constructed for gaseous slip flows in a micro-channel with different slip conditions. The micro-channel flow is investigated theoretically and numerically at various inlet pressure ratios, aspect ratios and fluid cases with several slip models. The influence of the rarefaction effect, thermal creep effect and slip conditions is emphasized. Simulations show that Kn is a key parameter in determining the magnitude of rarefaction effects while Re is a key parameter indicating the thermal creep. Excellent agreements with experimental results are observed in both theoretical and numerical results of low-velocity micro-channel flows at very large aspect ratios.