Effects of gas compressibility and surface roughness on the flow in microfluidic devices  

作　　者：YAO ZhaoHui HAO PengFei ZHANG XiWen 

机构地区：[1]School of Aerospace, Tsinghua University, Beijing 100084, China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2011年第4期711-715,共5页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No. 10872106)

摘　　要：With the development of the micro-electro-mechanical system (MEMS),the flow characteristics in micro-channels have drawn increasing attention.In this paper,numerical simulations are conducted to investigate the flow characteristics of compressible flow through micro-channels and micronozzles.An improved surface roughness viscosity model is used to simulate the effect of surface roughness on micro-channels flow characteristics.Using this model,better agreements between the computational results and the experimental data are found.The result indicates that the surface roughness is one of the important factors affecting the flow characteristics of gas through micro-channels.The numerical investigation on the expansion channel shows that by using the laminar model that considers surface roughness,the computational results and experimental data are consistent when Re<450,whereas deviation increases when Re>450.Based on the synthetic model with considerations of turbulence viscosity and surface roughness,the numerical results and the experimental data are identical.With the development of the micro-electro-mechanical system （MEMS）, the flow characteristics in micro-channels have drawn increasing attention. In this paper, numerical simulations are conducted to investigate the flow characteristics of compressible flow through micro-channels and micronozzles. An improved surface roughness viscosity model is used to simulate the effect of surface roughness on micro-channels flow characteristics. Using this model, better agreements between the computational results and the experimental data are found. The result indicates that the surface roughness is one of the important factors af- fecting the flow characteristics of gas through micro-channels. The numerical investigation on the expansion channel shows that by using the laminar model that considers surface roughness, the computational results and experimental data are consis- tent when Re〈450, whereas deviation increases when Re〉450. Based on the synthetic model with considerations of turbulence viscosity and surface roughness, the numerical results and the experimental data are identical.

关 键 词：microfluidic devices surface roughness compressible characteristics early transition 

分 类 号：TQ051.3[化学工程] TG84[金属学及工艺—公差测量技术]