3-D SIMULATION OF FREE MOLECULAR FLOW WITHIN SPIRAL-GROOVED MOLECULAR PUMP

摘要

The free molecular flow is solved in the spiral-grooved molecular pump using test-particle Monte Carlo scheme. The molecular motion including Coriolis and centrifugal acceleration is achieved in the non-inertial coordinate attached on the rotor. The representative molecules are followed within the multi-grooved channel to obtain direct and back transmission probabilities. Also the flow leakage from high-pressure side to low-pressure side is taken into account. The presented results in this paper show good agreement compared with those obtained by other researchers. The pump operation parameters in terms of non-dimensional geometrical parameters are also presented in non-dimensional form.