Normal and typhoon wind loadings on a large cooling tower: A comparative study. (May 2020)

• Record Type: Journal Article
• Authors: Fang, Genshen; Zhao, Lin; Chen, Xu; Cao, Jinxin; Cao, Shuyang; Ge, Yaojun
• Is Part Of: Journal of fluids and structures. Volume 95(2020)
• Publication Date: 2020-05
• Subjects: Normal winds -- Typhoon -- Cooling tower -- Wind tunnel test -- Correlation -- Non-Gaussian -- Extreme wind load; Fluid-structure interaction -- Periodicals; Fluid mechanics -- Periodicals; Structural dynamics -- Periodicals; Structural analysis (Engineering) -- Periodicals; 620.106
• DOI: 10.1016/j.jfluidstructs.2020.102938
• Languages: English
• ISSNs: 0889-9746

Abstract

Abstract: Large cooling towers are sensitive to wind effects with their increasing heights and flexibilities. Unlike traditional approaches, which employed Code-defined normal winds to check the loading characteristics, this paper developed a framework for checking the typhoon-induced wind loading on a large cooling tower using Monte Carlo simulations and multi-fan wind tunnel tests. Some distinct characteristics of typhoon winds were compared with those of Code-defined normal winds. Furthermore, wind characteristics of incoming normal and typhoon winds in terms of vertical profile of mean wind speed, turbulence intensity, turbulence integral length scale and power spectrum density of fluctuating winds were well reproduced by a feedback control process of a multi-fan actively controlled wind tunnel. The surface wind pressure distributions of a large cooling tower under these conditions were then investigated by testing a 1:600 reduced scale model. Mean and fluctuating external wind pressures along the circumferential direction under various incoming winds were discussed and quantitatively formulated with eight-term trigonometric equations. Moreover, the cross correlations of wind pressures in the circumferential and meridian directions and correlations with structure base forces, i.e. integral drag and lift forces, were investigated. Non-Gaussian characteristics in terms of skewness and kurtosis of fluctuating wind pressures were also analyzed under two wind climates. Peak factors for modeling extreme wind pressures were examined and compared with those of various models. Finally, the extreme wind loads on a large cooling tower obtained from different wind pressure combinations were compared with peak-factor-theory-based results to identify an appropriate combination for structural design.