奥行きの深いスリットのコンダクタンス; 圧力依存性

Conductance of a deep slit; Pressure dependence

荻原 徳男; 引地 裕輔*; 神谷 潤一郎   ; 金正 倫計  

Ogiwara, Norio; Hikichi, Yusuke*; Kamiya, Junichiro; Kinsho, Michikazu

The flow rate of a rarefied gas through a long rectangular channel with a very small height (H) to width (W) ratio was experimentally investigated using N and Ar for the wide range of the Knudsen number, which is defined as a ratio of H to the mean free path. Here the dimensions of the channel are as follows: H=0.1 mm, W=50 mm, and the length L=100 mm. The conductance, which is proportional to the dimensionless flow rate, decreases from the value in free-molecular regime and reaches the Knudsen minimum at K1.2, as the inlet gas pressure increases. Then the experimental data are compared with the computational results [Phys. Rev. E, 91 (2015) 061001] based on a direct simulation Monte Carlo method. A good agreement is found between the measured and the computed flow rates. Finally change in the distribution function of the emitted molecules from the channel due to the influence of the intermolecular collisions is simply estimated by accounting the change in last flight length for all the emitted molecules.