本研究利用Fluent 軟體模擬分析直線邊界和曲面邊界微噴嘴/擴大器的流力特性與比較其性能。結果顯示，微噴嘴和擴大器的壓損你數(已)會隨著雷諾數的增加而減小，但壓損你數比(η)反而會隨著雷諾數的增加而增大;而在中目同的雷諾數下，擴大器的壓損你教會低於嘖嘴的壓損你數。籍由各種不同外型微噴嘴/擴大器壓損你數之模擬值， 再與文獻中之解析值與實驗值比較，結果顯示，邊界為曲面形貌( 5/3 次方)之微噴嘴/擴大器雖然具有較高之壓損你數，但卻擁有比直線邊界較高之壓損條數比，因此能夠獲得較高之，驅動力，有效提高微型噴嘴/擴大器之驅動流量，且模擬值、實驗值皆與解析值相符合。因此未來於無閥幫浦之設計與應用，可提供一明確之參考依據。 This paper presents CFD-simulation of the performance of straight-walled and curved-walled Micro nozzle/diffuser by Fluent software. Such nozzle/diffuser are used in valveless micro-pumps. The results show that the pressure loss coefficient
for the nozzle/diffuser decreases with the Reynolds number whereas the ratio of the pressure loss coefficient increases with the Reynolds number. At the same Reynolds number, the pressure loss coefficient for nozzle is higher than that of the diffuser. The model is compared with different previously experimental measurements and shows good agreement. For a fixed volumetric flow rate, results show the curved profile bounder (y=ax5/3) nozzle/diffuser have higher pressure loss coefficient and higher ratio of the pressure loss coefficient as well than that of the straight profile bounder. The theoretical analysis and design basis can then be formulated for the reference and application need in the fabrication of micro nozzle/diffuser from this study.
