Distribution pattern of fluctuating wind pressures on cooling towers in grouped rectangular arrangement

Abstract

The cooling towers in this study are in a typical grouped arrangement. Traditional research on grouped-tower interference effects usually emphasizes equivalent static wind loads and ignores quantitative definition of interference effects under aerodynamic load, especially those for fluctuating wind pressure distribution patterns. An eight-tower rectangular arrangement with various aerodynamic interference characteristics was selected as the research object on which a rigid-model synchronous-pressure-measurement wind-tunnel test was performed. Fluctuating time-variant pressures on the tower surfaces for different wind directions was obtained. In three typical incoming flow modes: “windward flow”, “crosswind flow” and “leeward flow”, the fluctuating wind pressure distribution around circumferential directions can be summarized as “V” type, “M” type, and half “V” + half “M” type. The interference patterns can be defined as “weak interference”, “asymmetric strong interference” or “symmetric strong interference”, according to which a 9-item fitting formula of fluctuating wind pressure is proposed and a recommended distribution is given. Interference involving aerodynamic correlation and spectra characters of distributed wind loads are further discussed, and a fitting expression of a specific point spectrum is given. The research strategies and conclusions on fluctuating wind pressure interference provide a loading mode reference for evaluating wind resistance design of similar groups of structures.