稀薄气体流动特点及研究现状分析

随着航空航天技术以及微电子机械系统(MEMS)的发展和广泛应用，稀薄气体流动的研究越来越被重视。稀薄气体流动中涉及到稀薄效应问题，在传统流体力学中可忽略的一些影响因素，比如表面力，面容比，梯度参数效应等变得重要起来。由于尺度效应、表面效应等因素的影响，稀薄气体流动表现出自己的特点：流动涉及的表面积与体积之比增强、梯度参数效应，表面效应，流体极性等。针对微电子机械系统，对稀薄气体流动的研究现状进行了综述，并对其特点进行了分析。

Analysis of Research Status and Characteristics of Rarefied Gaseous Flow

With the advances and increasing applications of aeronautic technology and micro-electromechanical systems (MEMS),research on rarefied gaseous flow has gained more attention than before.In the rarefied gaseous flow,the rarefaction effect is often met.Some negligible factors in the classical fluid dynamics,such as,surface force,surface-volume ratio and the effects of gradient parameters,become very important for its study.Because of the influence of size effect and surface effect,the rarefied gaseous flow shows its own characteristic,such as the increment of surface-volume ratio related to the domain of flow,the effects of gradient parameters,surface effect,and fluid polarity and so on.With regard to the MEMS,the research advances on the rarefied gaseous flow are summarized and its characteristics are analyzed.