Numerical study on formation and diffusion wind fields for thunderstorm microburst

As a type of high intensity winds, thunderstorm microbursts have caused numerous structural failures around the world. The numerical method was employed to investigate the formation and diffusion unsteady wind fields for thunderstorm microburst related high intensity winds. Unsteady simulations of formation and diffusion wind fields were conducted using time-filtered Reynolds Averaged Navier-Stokes (RANS) numerical simulation method. The numerical results indicate that the wind fields present quite different characteristics at different time during the whole formation and diffusion process. The magnitude of wind velocity changes greatly during the whole formation and diffusion process. The maximum wind velocity occurs at the moment when the downdraft impacts on the ground and the main vortex is acting separation-reattachment, the secondary vortex is arising. Unsteady simulations supply a promising solution to study the thunderstorm microburst wind characteristics under the current conditions with lack detailed full scale data.