Numerical study of flow and dilution behavior of radial wall jet

The radial wall jet is a flow configuration that combines the radial jet and the wall jet. This article presents a simulation of the radial wall jet by applying the transition Shear-Stress Transport (SST) model. Tanaka's experimental data are used for validation. The computed velocity profiles agree well with the experimental ones. The distributions of the velocity on cross-sections show a similarity in the main region and the profiles are different with those of the free radial jet or the wall jet, because the presence of the wall limits the expansion of the jet. By introducing the equivalent nozzle width, the maximum velocity decays and the half-width distributions are normalized, respectively. In addition to compare the flow field with experiments, this paper also analyzes the dilution effect of radial wall jets in terms of the concentration distributions. The concentrations on the wall keep constant within a certain distance from the nozzle. And the concentration distributions also show a similarity in the main region. Both the decays of the maximum concentration and the distributions of the concentration half-width fall into a single curve, respectively. The dilution effect of radial wall jets is thus verified.