Optimal Design Combination of Suction Inlet Location and Nozzle Length of a Gas-driven Micropump

• Main Authors: Yu-Ning Wu, 吳祐甯
• Other Authors: S. G. Chuech
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/12727849185065327369

碩士 === 國立臺灣海洋大學 === 機械與機電工程學系 === 97 === In comparison to other micropumps with different driving methods, a negative-pressure micropump can drive arbitrary fluids and it has simpler structure. Therefore, a fixed-shape gas-driven micropump of negative- pressure type was used in the present study. The study utilized a CFD code of FLUENT and as the analysis tool to analyze the internal flow fields inside the micropump in which the nozzle length is varied with various openings of suction inlets. In order to obtain the optimal design for pumping flow rates of the micropump, the effects on micropump performance were analyzed by the various combinations of nozzle length and suction inlets. Major conclusions of the analyses for designing the gas-driven micropump were obtained in the present study. First of all, among the cases of single-opening and multi-opening vertical to the nozzle, the optimal suction flow rates could be obtained when the nozzle outlet location should correspond to the suction inlet opening. For the parallel single-opening cases, there was fewer shear force could disturb the flow due to the same directions of the suction inlet flow and the driving flow. As a result, the parallel cases were the optimal design of suction inlet opening in the present study. For the multi-opening cases, both suction inlet openings in the front of the pump and near the converging section could provide a better micropump flow rate. The reason for that is the suction flow rate is enhanced due to entrainment effects at the opening near the converging section of the micropump. For all of the single-opening and multi-opening cases in the study, the pumping capacity of the micropump significantly deteriorated when the nozzle length extended to the converging section of the micropump.