NUMERICAL SIMULATION OF GASEOUS FLOW CHARACTERISTICS IN MICROCHANNELS
Flow characteristics of nitrogen flows in the three different microchannels (hydraulic diameter Dh ranging 30-3000 m μ ) have been investigated numerically considering of the effect of compressibility and viscosity heating. It indicated that pressure drop at inlet and outlet is nonlinear with Reynolds number. Transition Re is as low as about 1200 for microchannels with Dh=300 m μ . To incompressible flow, Dh has no effect on friction factor f. However, L/Dh has great effect on f, and f increases with the decrease of L/Dh. It was found from numerical results that fRe can be expressed as a function of Mach number. By compared with the experimental results, the function has been proved right. When pressure drop at inlet and outlet is over 10kPa, the effect of compressibility could not be neglected. This implies that the effect of compressibility in microchannels can be described better by pressure drop at inlet and outlet than Ma, which is in contrast to the practice in the conventional scale. At last, the viscosity heating effect was simply analyzed. It was found that the effect of viscosity heating increases with the increase of Re and decrease of size.
microchannel numerical simulation flow characteristics friction factor compressibility
Tiantian ZHANG Li JIA
Department of Power Engineering, School of Mechanical and Electronic Control Engineering, Beijing Jiaotong University, China
国际会议
海南三亚
英文
2007-01-10（万方平台首次上网日期，不代表论文的发表时间）