【摘要】 采用了表面粗糙度粘性系数模型对微细管内的气体流动进行数值模拟 ,以研究微管内壁表面粗糙度对微管内气体流动的影响。运用本文改进的表面粗糙度粘性系数模型 ,数值模拟与实验数据十分吻合。计算结果表明 ,进出口压力一定时 ,表面粗糙度对流场的压力、密度及温度分布的影响不大 ,但是对速度场的影响十分显著 ,表面粗糙度使气体流动速度减小 ,并使壁面附近的速度梯度减小 ,从而使通过管道的气体质量流量减小 ,在微管内的气体流动中 ,表面粗糙度的影响是不能被忽略的。更多还原

【Abstract】 Numerical simulations are conducted to investigate the effects of surface roughness on flow characteristics of gas through microchannels by introducing a surface roughness viscosity. Using the modified surface roughness viscosity model, an excellent agreement between the numerical results and the experimental data is found. The computational results indicate that surface roughness has little influence on pressure, density and temperature of the flow field. But its effect on velocity of the flow field is pronounced. The velocity of the gas flow and the velocity gradient near the wall is decreased. Therefore the mass flow rate through the microchannels is also decreased. The effects of surface roughness on the gas flow in microchannels should not be neglected.更多还原