本研究探討各式鋸齒狀微流道無動件閥之設計。無動件閥為不具活動元件的閥門，應用於微流道時，其工作原理是以不對稱的流道幾何形狀，使流道中往返流動之阻力不同，具有如同單向閥的阻力雙極性效果。其不具活動元件的設計可省去複雜的結構，並避免阻塞，或對流體中分子造成傷害。
本研究以計算流體力學為工具，針對各種擴張閥以及鋸齒狀結構之無動件閥作計算與分析，就不同構型於不同雷諾數下阻力雙極性變化探討其差異。本研究發現，在某些雷諾數範圍時阻力雙極性可能發生方向變異（Diodicity Reversal），並對無動件閥之效能表現產生顯著影響。本研究試圖就此雙極性方向變異現象提出改良設計。

This thesis compares various designs of Saw-toothed No-Moving-Part Valves (NMPV) for flows in micro-channels. NMPV is a valve design without any mechanical moving-part. The working principle of NMPV is the drag diodicity resulting from the asymmetric shape of the flow passages of the valve design. Under the same pressure difference across the valve, the flow drag is smaller in one direction (the preferred direction) than the drag in the opposite direction. This drag diodicity allows the flow passage function like a one-way check valve. Comparing with the traditional mechanical valves, a NMPV has the advantage of simplicity in both design and manufacturing, and also avoids the possible damage to fluid particles due to the on/off motion of the mechanical pump.
This research uses Computational Fluid Dynamics as a tool to analyze designs of NMPV. In particular, the Reynolds number effect on various saw-toothed NMPV and diffuser valves are examined. It is found that in certain range of Reynolds number, the drag diodicity reversal will significantly affect the performance of a NMPV.

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