Turbulence effects of wall-pressure fluctuations for reattached flow

Abstract

A methodology is presented to predict the frequency spectrum of fluctuating wall-pressures based on a steady Reynolds Averaged Navier Stokes (RANS) solution. The spectral modeling scheme solves a Poisson equation with a linear source term (LST) for the mean-velocity–turbulence interaction (MT) and non-linear source terms (NST) for the turbulence–turbulence interaction (TT). An anisotropic factor is used to account for the anisotropic features of the turbulence field. The prediction method was originally developed based on the equilibrium flow, i.e. turbulent flow with homogeneous and stationary characteristics, with the LST only. In this paper, the model is further applied to a non-equilibrium flow, i.e. flow over a backward facing step (BFS), to explore its predictability for the wall-pressure fluctuations. With the help of DNS results and experimental data for the BFSs, the model is investigated with the inclusion of NST. Prediction results demonstrate the impact of turbulence features of the wall shear layers to the predicted wall-pressure spectrum.