Comparison of Experimental and RANS Based Numerical Studies of the Decay of Grid Generated Turbulence

Abstract

This paper presents both experimental and numerical studies of the statistical properties of turbulent flows at moderate Reynolds number (Reخ»â€‰= 100) in the context of gridgenerated turbulence. In spite of the popularity of passive grids as turbulence generators, their design relies essentially on empirical laws. Here, we propose to test the ability of simple numerical simulations to capture the large scale properties (rootmeansquare (rms) velocity, turbulence decay, pressure drop, etc.) of the turbulence downstream a passive grid. With this purpose, experimental measurements are compared with the threedimensional (3D) ReynoldsAveraged Navier–Stokes (RANS) equations based turbulence model simulations. To better modeling of energy cascade of turbulence, different turbulence models, mesh resolutions, and turbulence model constants, which are determined in accordance with the experimentally measured corresponding values, are used. Both qualitative and quantitative comparisons are made with the experimental data to further assess the accuracy and capability of present numerical techniques for their use in different aerodynamic applications at moderate Re number.