A Study on No-Moving-Part Valves for Flows in Microchannels
| Autor: | Peng-Fei Liao, 廖鵬飛 |
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| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 92 This thesis studies the design of no-moving-part valves (NMPV) for flows in microchannels. By definition, a no-moving-part is a valve without any moving element. Comparing with the valve design with one or more moving parts, a NMPV is advantageous in that it eliminates (1) the difficulty in manufacturing the moving elements in small sizes, (2) the risk of malfunctioning of the moving part due to the impurity in the fluid flow and (3) the risk of damaging certain component of the fluid flow due to the valve movement. A NMPV is a specially-designed flow passage that when the flow direction is reversed, the flow experiences different flow resistances. This is the so-called resistance diodicity. For a NMPV passage under a fixed pressure difference, different flow direction will yield different mass flow rate, and hence it can be used as a check valve. In this study, the resistance diodicity is obtained by the design of sawtooth-like channel wall. Computational Fluid Dynamics is used as a design tool to examine the effect of geometry change on the resistance diodictiy. The geometric parameters are carefully chosen under the consideration of avoiding excessive micropump working pressure and ensuring the structure integrity of the design. Finally, experiments involving 10-3m size microchannels are conducted to verify the final design of NMPV chosen in this study. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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