I studying about DSMC. (And I'm not native speaker, so please understand my low command of writing) and when I apply the Virtual Sub Cell(VSC), the result was not acceptable. The particle number is 30 and cell size is one mean free path. The temperature result is good with BENCHMARK test. But shear stress was not. Shear stress is very larger than result of BENCHMARK test and no VSC applied DSMC result. I don't know why, how this result followed. Is there anyone knows about this problem??