高校化学工程学报2017，Vol.31Issue(6)：1285-1292,8.DOI:10.3969/j.issn.1003-9015.2017.06.005
气体在热流逸效应作用下的压力与流量特性
Pressure and Mass Flow Characteristics of Gases under Thermal Transpiration Effects
摘要
Abstract
In order to better understand thermal transpiration, geometric coefficient (LND) and reduction ratio of net mass flow (ΨM) were defined to study pressure difference variation and net mass flow of 13 gases under thermal transpiration effects with different microchannel structures, gas properties, flow regimes and temperatures. The results indicate that the net mass flow decreases rapidly with the increase of Knudsen number (Kn) and LND, and it reduces by 99% at Kn ≈ 2.4 or LND ≈ 1000. In the transitional flow regime, the net mass flow of most non-polar gases is higher than those of polar gases, and lower viscosity index results in higher net mass flow. In the free molecular flow regime, the gas with larger molecular mass or viscosity results in higher net mass flow. The pressure difference enlarges with the increase of Kn in the transitional flow regime and approaches to a constant maximum in the free molecular flow regime, which is ~17.8% higher than the peak in the transitional flow regime. Moreover, the net mass flow and pressure difference increase approximately by 18% and 15% respectively with every 10 K rise of temperature difference. The temperature difference has stronger effects on net mass flow of gas with larger viscosity indices in the transitional flow regime. Suitable flow regime and microchannel structure should be determined according to practical requirements due to the coupling effects between microchannel dimension and flow regime. Suggestions are given for applications based on thermal transpiration effects.关键词
热流逸效应/微通道/净质量流量/压差/结构尺寸Key words
thermal transpiration effect/microchannel/net mass flow/pressure difference/structure分类
数理科学引用本文复制引用
徐昆,卢苇,王博韬,王祥..气体在热流逸效应作用下的压力与流量特性[J].高校化学工程学报,2017,31(6):1285-1292,8.基金项目
广西自然科学基金(2016GXNSFAA380232) （2016GXNSFAA380232）
国家自然科学基金(51366001). （51366001）
