21824 マイクロチューブを流れるスリップ流の摩擦係数の整理式(ミニ・マイクロ・ナノスケールの流れおよび熱の現象,OS.5 ミニ・マイクロ・ナノスケールの流れおよび熱の現象)

抄録

Poiseuille number, the product of friction factor and Reynolds number (f・Re) for quasi-fully developed flow in a micro-tube was obtained in slip flow regime. The numerical methodology is based on the Arbitrary-Lagrangian-Eulerian (ALE) method. Two-dimensional compressible momentum and energy equations were solved for a wide range of Reynolds and Mach numbers for CWT (constant wall temperature) that is higher or lower than inlet temperature. The tube diameter ranges from 3 to 10μm and the tube aspect ratio is 200. The stagnation pressure, p_<stg> is chosen in such away that the exit Mach number ranges from 0.1 to 1.0. The outlet pressure is fixed at the atmospheric pressure. Mach and Knudsen numbers are systematically varied to determine their effects on f・Re. The correlation for f・Re of the slip flow is obtained from numerical results. It was found that f・Re is mainly a function of Mach number and Knudsen number and is different from the values obtained by 64/(1+8Kn), from the incompressible flow theory. The obtained f・Re correlations are applicable to both no-slip and slip flow regimes.