Study of Flow Characteristics of Gas Mixtures in a Rectangular Knudsen Pump
A Knudsen pump operates under the thermal transpiration effect or the thermal edge effect on the micro-scale. Due to the uneven temperature distribution of the walls in the channel axis direction or the constant temperature of the tips on the walls, directional thermally-induced flow is generated. I...
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doaj-28ee5d6caf6e4672983a9b76ade873512020-11-24T20:44:28ZengMDPI AGMicromachines2072-666X2019-01-011027910.3390/mi10020079mi10020079Study of Flow Characteristics of Gas Mixtures in a Rectangular Knudsen PumpZhijun Zhang0Xiaowei Wang1Lili Zhao2Shiwei Zhang3Fan Zhao4School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819, ChinaSchool of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819, ChinaSchool of Mechanical Engineering, Shenyang University, Shenyang 110044, ChinaSchool of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819, ChinaSchool of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819, ChinaA Knudsen pump operates under the thermal transpiration effect or the thermal edge effect on the micro-scale. Due to the uneven temperature distribution of the walls in the channel axis direction or the constant temperature of the tips on the walls, directional thermally-induced flow is generated. In this paper the Direct Simulation Monte Carlo (DSMC) method is applied for N<sub>2</sub>⁻O<sub>2</sub> gas mixtures in the ratios of 4:1, 1:1, and 1:4 with different Knudsen numbers in a classic rectangular Knudsen pump to study the flow characteristics of the gas mixtures in the pump. The results show that the changing in the gas physical properties does not affect the distribution of the velocity field, temperature fields, or other fields in the Knudsen pump. The thermal creep effect is related to the molecular mass of the gas. Even in N<sub>2</sub> and O<sub>2</sub> gas mixtures with similar molecular masses, N<sub>2</sub> can be also found to have a stronger thermal creep effect. Moreover, the lighter molecular weight gas (N<sub>2</sub>) can effectively promote the motion of the heavier gas (O<sub>2</sub>).https://www.mdpi.com/2072-666X/10/2/79Knudsen pumpthermally induced flowgas mixturesdirect simulation Monte Carlo (DSMC)microfluidic |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Zhijun Zhang Xiaowei Wang Lili Zhao Shiwei Zhang Fan Zhao |
spellingShingle |
Zhijun Zhang Xiaowei Wang Lili Zhao Shiwei Zhang Fan Zhao Study of Flow Characteristics of Gas Mixtures in a Rectangular Knudsen Pump Micromachines Knudsen pump thermally induced flow gas mixtures direct simulation Monte Carlo (DSMC) microfluidic |
author_facet |
Zhijun Zhang Xiaowei Wang Lili Zhao Shiwei Zhang Fan Zhao |
author_sort |
Zhijun Zhang |
title |
Study of Flow Characteristics of Gas Mixtures in a Rectangular Knudsen Pump |
title_short |
Study of Flow Characteristics of Gas Mixtures in a Rectangular Knudsen Pump |
title_full |
Study of Flow Characteristics of Gas Mixtures in a Rectangular Knudsen Pump |
title_fullStr |
Study of Flow Characteristics of Gas Mixtures in a Rectangular Knudsen Pump |
title_full_unstemmed |
Study of Flow Characteristics of Gas Mixtures in a Rectangular Knudsen Pump |
title_sort |
study of flow characteristics of gas mixtures in a rectangular knudsen pump |
publisher |
MDPI AG |
series |
Micromachines |
issn |
2072-666X |
publishDate |
2019-01-01 |
description |
A Knudsen pump operates under the thermal transpiration effect or the thermal edge effect on the micro-scale. Due to the uneven temperature distribution of the walls in the channel axis direction or the constant temperature of the tips on the walls, directional thermally-induced flow is generated. In this paper the Direct Simulation Monte Carlo (DSMC) method is applied for N<sub>2</sub>⁻O<sub>2</sub> gas mixtures in the ratios of 4:1, 1:1, and 1:4 with different Knudsen numbers in a classic rectangular Knudsen pump to study the flow characteristics of the gas mixtures in the pump. The results show that the changing in the gas physical properties does not affect the distribution of the velocity field, temperature fields, or other fields in the Knudsen pump. The thermal creep effect is related to the molecular mass of the gas. Even in N<sub>2</sub> and O<sub>2</sub> gas mixtures with similar molecular masses, N<sub>2</sub> can be also found to have a stronger thermal creep effect. Moreover, the lighter molecular weight gas (N<sub>2</sub>) can effectively promote the motion of the heavier gas (O<sub>2</sub>). |
topic |
Knudsen pump thermally induced flow gas mixtures direct simulation Monte Carlo (DSMC) microfluidic |
url |
https://www.mdpi.com/2072-666X/10/2/79 |
work_keys_str_mv |
AT zhijunzhang studyofflowcharacteristicsofgasmixturesinarectangularknudsenpump AT xiaoweiwang studyofflowcharacteristicsofgasmixturesinarectangularknudsenpump AT lilizhao studyofflowcharacteristicsofgasmixturesinarectangularknudsenpump AT shiweizhang studyofflowcharacteristicsofgasmixturesinarectangularknudsenpump AT fanzhao studyofflowcharacteristicsofgasmixturesinarectangularknudsenpump |
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