Large eddy simulation of a plane turbulent wall jet

Abstract

The mean-flow and turbulence properties of a plane wall jet, developing in a stagnant environment, are studied by means of large eddy simulation. The Reynolds number, based on the inlet velocity Uo and the slot height b, is Re = 9600, corresponding to recent well-resolved laser Doppler velocimetry and pulsed hot wire measurements of Eriksson et al. The relatively low Reynolds number and the high numerical resolution adopted (8.4 million nodes) allow all scales larger than about 10 Kolmogorov lengths to be captured. Of particular interest are the budgets for turbulence energy and Reynolds stresses, not available from experiments, and their inclusion sheds light on the processes which play a role in the interaction between the near-wall layer and the outer shear layer. Profiles of velocity and turbulent Reynolds stresses in the self-similar region are presented in inner and outer scaling and compared to experimental data. Included are further results for skin friction, evolution of integral quantities and third-order moments. Good agreement is observed, in most respects, between the simulated flow and the corresponding experiment. The budgets demonstrate, among a number of mechanisms, the decisive role played by turbulent transport (via the third moments) in the interaction region, across which information is transmitted between the near-wall layer and the outer layer.