Application of second-moment closure to statistically steady flows of practical interest

Abstract

This work investigates the application of second-moment Reynolds-Averaged Navier-Stokes equations (RANS) closure to statistically steady flows of practical interest. Towards this end, the numerical and modelling accuracies of a Reynolds-Stress Model (RSM), Explicit Algebraic RSM (EARSM) and linear k−ω closure are quantified for various quantities of three representative ship hydrodynamics problems: the flows around a wing at 10o of angle of attack and Reynolds number Re=4.60×106, and the KVLCC2 tanker at Re=4.60×106 and 2.03×109. The results illustrate i) that all closures enable the reduction of the iterative error to negligible levels, and ii) the clear modelling advantages of using RSM. In comparison to the turbulent viscosity closures, RSM leads to a significant reduction of the modelling error. Yet, such computations require a larger number of iterations to achieve the specified iterative convergence criterion, along with finer grids to diminish discretization errors. This stems from the ability of RSM to better capture complex flow phenomena.