임의단면 형상을 갖는 축대칭 물체주위의 난류유동장 해석에 2차 Reynolds 응력모형 방정식의 응용

Abstract

A new curvature-dependent Reynolds stress model (CRSM) is proposed for prediction of complex turbulent flows. A curvature time scale for third-order diffusive transport terms in the Reynolds stress equation is assumed, which is drove from the analogy between the buoyancy and streamline-curvature effects on turbulence. The model coefficient of the destruction term in the rate of energy dissipation equation is also modified by the proposed time scale in order to incorporate the streamline-curvature effect on the decay rate of turbulent kinetic energy. The CRSM is applied to mildly curved axisymmetric bodies such as an afterbody without flow separation and a spheroid with small separation bubble at the tail. The transport governing equations are discretized in the numerically generated body-fitted grids using the recently developed finite analytic method. The results show that the present CRSM yields better prediction than the standard k-εturbulence model. In particular, the mean velocity and turbulent kinetic energy profiles are in very good agreement with the experimental data.