A Numerical Simulation Method of Non-stationary Fluctuating Wind Velocity in Downburst

Abstract

The invention provides a numerical simulation method for a downburst non-stationary fluctuating wind speed. The method comprises the steps of modulating a power spectrum through a time varying average wind speed model of the downburst and an inhomogeneous modulation function related to time frequency so as to obtain the time varying power spectrum of the downburst non-stationary fluctuating wind speed; building a TAR (Terrain Avoidance Radar) time varying model of a stationary stochastic process by further considering the time varying characteristic of an AR (Access Rate) model of the stationary stochastic process; and effectively stimulating the downburst non-stationary fluctuating wind speed by the time varying power spectrum and the TAR time varying model. The relevance of the downburst non-stationary fluctuating wind speed simulated by the numerical simulation method provided by the invention can be weakened along with the increasing of the distances among different positions, the amplitude can be improved to be consistent with the characteristics of a practical wind field as the time varying average wind speed is improved; the power spectrum of the simulated downburst non-stationary fluctuating wind speed has an obvious time varying characteristic, and is consistent with the time varying characteristic of a target time varying spectrum, and the average power spectrum of sample statistics and relevant functions are consistent with the targets.

Description

technical field [0001] The invention belongs to the technical field of storm simulation, and in particular relates to a numerical simulation method for non-stationary fluctuating wind speed of a downburst. Background technique [0002] In thunderstorm weather, local strong downdrafts often form and violently hit the ground, producing a very sudden and destructive strong wind, namely downburst. The catastrophic nature of downbursts was first recognized in the 1975 crash of a Boeing 727 landing in the United States. After investigating the accident, Fujita proposed for the first time the downburst, which is a strong downdraft that can generate a divergent wind above 17.9m / s on the ground [1] . Chay and Letchford [2] Essentially, the formation method of the downburst wind speed is elaborated in detail. In a thunderstorm environment, small-scale microbursts occur frequently, and the maximum wind speed near the ground can reach 75m / s [3] . Obviously, it is particularly dest...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a numerical simulation method for non-stationary fluctuating wind speed of downburst, which aims to solve the problem in the prior art that avoids the difficulty of simulating non-stationary random processes based on time-varying power spectrum

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