Large eddy simulations of a circular jet impinging on a flat plate have been carried out. The distance between the jet nozzle and the plate was varied between 2 and 6 nozzle diameters and the Reynolds number was 10000. The aim of the work is by using large eddy simulations study the mixing properties and how they are influenced by the nozzle to wall distance in the region close to the impingment wall.
The computational code is a multi-grid finite difference code using a staggered grid. The results show that turbulence level close to the stagnation point is substantially increased when the impingement distance exceeds 4.0 nozzle diameters. However, this seem to have little effect on the maximum level of concentration fluctuations in the developing wall jet.