Method for determining downburst crosswind profile

Abstract

The invention provides a method for determining a downburst crosswind profile. The method comprises the following steps that a downburst crosswind field is determined; ground boundary layer parameters are determined; the downburst crosswind profile is determined. According to the method for determining the downburst crosswind profile, the crosswind profiles within the range of the height smaller than the height of the position with the maximum wind speed are corrected, and the theoretical reference is provided for the engineering design.

Description

technical field [0001] The invention relates to a determination method, in particular to a determination method of a downburst transverse wind profile. Background technique [0002] A downburst is a strong wind formed after the rapid downdraft hits the ground violently in a thunderstorm. The lateral wind speed of the strong wind increases rapidly with the height in the area near the ground, and reaches the maximum lateral wind speed (up to 70m / s) at a relatively small height (within 100m), which is very important for falling within the height range of the strong wind. Buildings such as power transmission towers are extremely destructive. For example, on June 14, 2005, the downburst caused an accident in which 10 transmission towers collapsed on the 5237 line of the 500kV line in Siyang, Jiangsu Province; according to the analysis of the causes of the transmission tower collapse accidents in the United States, Australia, South Africa and other countries , More than 50% of t...

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Problems solved by technology

However, it is impossible for engineering design to wait for the results of downburst wind profile observed on site, and the cycle of experimental simulation and numerical simulation is long and expensive. Therefore, the empirical formula of wind profile with simple form and high calculation efficiency has been widely used in the field of engineering design. applications, and researchers are constantly improving the relevant wind profile formulas to make them closer to the measured results

[0004] In the past, almost all research work on empirical formulas for wind profiles focused on the fitting of axisymmetric steady-state wind profiles, and a wealth of research results have been obtained; however, since these fitting methods are essentially data fitting in the Pay attention to the physical phenomenon of the evolution of the boundary layer after the downburst hits the ground

Generally speaking, the height of a large number of buildings is within 100m, that is, they fall within the height range below the maximum lateral wind speed position of the downburst. Insufficient description of the wind profile in the following height ranges leads to low prediction accuracy of wind loads on ground buildings

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