THE SCALING AND SELF-SIMILARITY OF THE VELOCITY AND CONCENTRATION PROFILES FOR A POLLUTANT-CONTAINED IMPINGING JET IN CROSSFLOW

The scaling and self-similarity of the velocity and concentration profiles for a pollutant-contained impinging jet in crossflow were investigated on the basis of corresponding numerical results of three-dimensional flow and concentration fields in near region by employing the RNG turbulence model and large-eddy simulation (LES). The computed results indicate that there exists no universal similarity scaling for the impinging jet in crossflow owing to high three-dimensionality of the flow pattern and the anisotropy of the turbulence transportation in overall near region. The relative appropriate characteristic scales in various subregions of the impinging jet in near region depend mainly upon the directionality and flow regime. The velocity profiles along the jet axial direction display height-dominant scaling in the impingement subregion due to the slight deflected jet trajectory, and the approximate self-similarity of the velocity and concentration decays along the longitudinal direction still vary with the velocity ratio and water depth in the transition subregion under the domination of the laterally-spreading wall jet, respectively.