Experimental measurement and numerical simulation of an impinging jet with application to thunderstorm microburst winds

Wind profiles and characteristics in a thunderstorm downburst are significantly different from that of regular boundary layer winds. This paper deals with the experimental and numerical simulation of a type of thunderstorm wind, namely the microburst, to study the outflow velocity characteristics. The microburst is simulated as a round jet, impinging onto a flat plate. A generic empirical equation for radial velocity profile is developed based on the experimental data, using hotwire, pressure rakes and particle image velocimetry (PIV). The experimental results are used to validate CFD simulations and to find the applicability of different turbulence models for this kind of flow. Favorable agreement between numerical and experimental studies indicates that CFD can be used for this kind of complex flow.