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摘要
This study investigated the effect of rarefaction on microchannel gas flow by measuring pressure profiles in microchannels with various aspect ratios. Pressure-sensitive paint (PSP) was applied in rectangular microchannels to obtain the global flow field by using detailed pressure data. The effect of rarefaction on the microchannel gas flow was clearly observed in the microchannels through the pressure data obtained using PSP measurements. A nonlinear pressure distribution was observed inside the micro channels, and this distribution decreased as the Knudsen number (Kn) increased because of the rarefaction effect. The dimensionless pressure deviation from the linear assumption dropped from 0.25 to 0 when the outlet Kn number increased to 0.066 in the 100-mu m-wide microchannel, and the dimensionless location of the maximum deviation moved upstream because of the gaseous slip at the wall. The nonlinear pressure distribution also decreased in the 50-mu m-wide microchannel as the outlet Kn number increased; however, the peak of the maximum deviation could no longer be identified because of the characteristic of the narrow channel.
- 出版日期2017-2
- 单位清华大学
