A Study of the Unsteady Characteristics of a Saw-toothed No-Moving-Part Valve in Micro-channel

• Main Authors: Yun-Hsiang Chang, 張雲翔
• Other Authors: Dartzi Pan
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/62088178265854998147

碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 95 === This thesis investigates the unsteady characteristics of a saw-toothed no-moving-part valve (NMPV) in micro-channel. The design of a NMPV avoids the use of moving-parts. The channel interior geometry is specially desighed to achieve different flow resistance in different flow directions. Under the same pressure difference, the channel flow rate is higher in the direction of smaller resistance. When two NMPV’s are installed properly on the two ends of a pump chamber, a net flow rate will be accumulated in the designed flow pumping direction. The unsteady characteristics of the NMPV installed plays a major role in determining the pump flow rate. This thesis utilizes CFD as the research tool to study the unsteady characteristics of a saw-toothed NMPV. A diffuser valve and a nozzle valve are used as reference valves for comparison. The numerical results show that, in 2D calculations, when the oscillation frequency of the pump membrane is smaller than or equal to 32 Hz, the saw-toothed NMPV pump has the highest pump flow rate, the nozzle valve pump has less pump flow rate, and the diffuser valve pump has the least pump flow rate. On the contrary, when the oscillation frequency of the pump membrane is greater than 32 Hz, the saw-toothed NMPV pump has less pump flow rate than the other two reference valves. In 3D calculations, the results for pump frequency 32Hz and 100Hz show that the saw-toothed NMPV has the highest pump flow rate among the three NMPV pumps at both frequencies.