Numerical analysis of unsteady gas entrainment phenomena using dynamic SGS model

Sakai, Masayuki*; Tanaka, Nobuatsu*; Ohshima, Hiroyuki

Proceedings of 5th Korea-Japan Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-5), p.301 - 304, 2006/11

The flowing gas or liquid in the industrial machines, it is important that improving in quality. We analyzed about systems of unsteady gas entrainment with the analysis code for turbulence eddy flow, which based on local inter-scale equilibrium assumption (LISEA). And we speculated about adequacy of LES application and affect of mesh division on unsteady gas entrainment phenomenon. In the result, we obtain the following knowledge about unsteady eddy problems as object. (1) LES affected by mesh division more than DNS. So appropriate result needs to give consideration to mesh division. (2) DNS affected lightly by mesh mutation in the purview of this analysis. (3) In the case of using LES, it needs to set proper parameters carefully.