RANS modelling and LES of a single-phase, impinging plane jet

Reynolds-averaged Navier–Stokes (RANS) modelling and large eddy simulation (LES) of a plane air jet impinging orthogonally on a flat surface is described. Comparisons of predictions are made with the data of Yoshida et al. for a Re=10,000 flow, with good agreement found in both the free and wall jet regions. Some under-prediction, particularly by the RANS approach, of turbulence quantities is apparent, and overall the LES is clearly in closer agreement with data, particularly in zones where large turbulence structures dominate. Differences in LES and RANS for the particular flow considered are not large, however, and this may be attributed to the significant effort already expended in the development of second-moment turbulence closures with wall reflection effects for impinging flow application. The results presented go some way towards validating LES for application to impinging flows, although uncertainties in the data set used for comparison purposes demonstrate a requirement for further experimental work.