Reynolds-Averaged Navier-Stokes modeling of a turbulent forced plume in a stratified medium

Abstract

We present here a computational study of turbulent forced plume released in a varying density environment. The buoyancy frequency N∞ and the Richardson number (Ri) considered in this study are 0.4 s-1 and 0.1, respectively. The Unsteady Reynold-Averaged Navier-Stokes simulations are conducted to evaluate the capabilities of different turbulence models. First, a grid independence study is performed to finalize the grid parameters. Then, simulations were performed using various k-ε turbulence models. The passive scalar contours reveal that the plume reaches a maximum height before it spreads laterally. The velocity contours for the standard k-ε model were compared with a reported experimental study and a good agreement is observed. The mean centerline vertical velocity profile throughout the plume height is compared using different k-ε turbulence models and similar trends are observed for different turbulence models. Overall, we observed that all the variants of k-ε turbulence models capture the macroscale physics accurately, however, the r.m.s. error is the least for the standard k-ε model when compared with the reported experimental study.