개선된 PANS 난류 모델을 이용한 높은 레이놀즈 수를 갖는 실린더 주위 난류 유동에 대한 수치 모사

Abstract

Computational simulations of turbulent flows around a circular cylinder were performed to investigate the drag coefficient and Strouhal number at sub-critical and critical Reynolds numbers. Unstructured grids with 3.1 million cells including prism layers were used in the present study. Both RANS and PANS simulations using k-ω SST model failed to predict a transitional behavior of drag coefficient and vortex shedding frequency at sub-critical and critical Reynolds numbers due to the absence of laminar separation bubble. But a hybrid combination of unresolved turbulence viscosity in PANS and sub-grid scale turbulence viscosity in LES provided a good agreement of drag coefficient and vortex shedding frequency with previous results.