Abstract
Speedup of the DSMC calculation has been investigated by the parallel processing using a CPU with multiple cores or threads and using the intermolecular collision scheme U-system which enables coarse cell networks for calculations near atmospheric pressure condition. According to my recent analysis, it has been demonstrated that physical properties in each cell of the U-system alter in accordance with a location within the cell. The underexpanded jet through an orifice, upstream stagnation pressure 101300 Pa and pressure ratio 50, 10, 7 or 4, is calculated by Bird's collision scheme and by the U-system. An effect of the upstream calculation region of the orifice is also examined.
