Study on numerical simulation of fluctuating wind for thunderstorm microburst using harmony superposition method

Abstract

Thunderstorm microburst is an outburst strong wind on or near the ground, and its field characteristics are significantly different from boundary layer winds. As a kind of high intensity winds, thunderstorm microburst have caused numerous structural failures around the world. The paper studied numerical simulation of fluctuating wind for microburst using harmony superposition method. The stochastic process of fluctuating wind speed was converted to a uniformly modulated stochastic process. The harmony superposition method with introducing fast Fourier transform (FFT) technique was applied to simulate the uniformly modulated stochastic process. As a numerical example, good agreement is achieved between data from the method and full-scale data from a high intensity downburst that occurred at Andrews Air Force Base in 1983.