2022 Fiscal Year Final Research Report
Study on similarity law and flow analysis of Knudsen pump driven by thermal creep flow.
| Project/Area Number |
19K04190
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 19010:Fluid engineering-related
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| Research Institution | Yokohama National University |
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Principal Investigator |
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| Project Period (FY) |
2019-04-01 – 2023-03-31
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| Keywords | 希薄気体流れ / 熱誘導流れ / 熱ほふく流 / Knudsen ポンプ / 流れの相似則 / DSMC / 速度すべりと温度ジャンプの条件 |
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| Outline of Final Research Achievements |
In this study, the efficiency of a Knudsen pump system was investigated experimentally under low pressure condition of 10 Pa. In addition to the experiment, the relation between the efficiency of Knudsen pump and thermal creep flow was examined numerically and the similarity law was investigated by comparing of the simulation between the micrometer and millimeter size pump system. It was confirmed that the maximum efficiency was obtained for Kn=0.1 and that there is an optimum device distance giving maximum efficiency. Simulation results suggest that the device has the role of a pump. Furthermore, with the aim of applying the micro-scale semiconductors composed of Al-Ga-As and Ga-As-Si to pump system operating at normal pressure, the micrometer size and millimeter size pump systems were simulated numerically. It was confirmed that the law of similarity holds when the Knudsen number of the system and the temperature gradient of the driving part are matched.
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| Free Research Field |
流体工学
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| Academic Significance and Societal Importance of the Research Achievements |
熱ほふく流れを利用したポンプシステムが，ペルチェ素子を複数枚並べるといった単純な構造で作成できることを確認し，その性能を実験と計算により検討した。ポンプ効率と希薄度，最適な素子間隔などを実験と数値解析により明らかにした。近年提案された，Al-Ga-AsとGa-As-Siからなるミクロスケールの半導体を常圧下で稼働するKnudsenポンプに適用するために，常圧下と低圧下でのシミュレーションを行い，Knudsen 数と駆動部の温度勾配を一致させると流れ場が相似になることを示した．
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