화학공학소재연구정보센터
Journal of Vacuum Science & Technology A, Vol.20, No.3, 906-910, 2002
Direct simulation of rarefied gas flows in rotating spiral channels
The pumping characteristics of a two-stage disk-type drag pump from the free molecular flow region to the slip flow region are calculated by the direct simulation Monte Carlo method. Spiral channels are cut on both upper and lower sides of rotating disks. For the molecular collision kinetics, the variable hard-sphere molecular model with the no time counter technique is employed. The Borgnakke-Larsen phenomenological model is adopted for calculation of the rotational energy exchange between the colliding molecules. Experiments are performed under the outlet pressure range of 0.4-526 Pa. Numerical results show good quantitative agreement with the experimental data.