Measurement of the Unsteady Performance of Microdiffusers

• Main Authors: Chiao-wen chen, 陳巧雯
• Other Authors: Yi-Chun Wang
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/68968263049810539657

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 94 === Abstract The purpose of the present study is to design and fabricate the test platform used for measuring the loss coefficients of microdiffusers under an unsteady flow field. The fluid is pumped by a piston which is driven by a ceramic piezoelectric actuator. The displacement of the piston is measured by a Doppler laser interferometer so that the instantaneous volume flow rate can be obtained. Pressure variations across the microdiffusers are measured by a dynamic pressure sensor. Two microdiffusers with expanding angle of and respectively are tested. Experiment results, show that the loss coefficient in the negative (nozzle) direction is greater than that in the positive (diffuser) direction for both of the microduffusers. Furthermore, for both of the flow directions, the loss coefficient of -diffuser is greater than that of -diffuser. It is also found that the best efficiency of the diffuser depends on operational frequency. The best frequency is 5Hz as the expanding angle is and 12Hz as the expanding angle is .