TIME-FREQUENCY CHARACTERISTICS AND RELEVANCE OF FLUCTUATING WIND PRESSURE OF GROUPED COOLING TOWERS

The traditional research of grouped-towers interference effect usually emphasizes the equivalent static wind loading of the tower tubes, lacking research on the interference characteristics of the group tower arrangement to the fluctuating wind pressure. A rectangular arrangement of eight towers with various aerodynamic interference characteristics was selected as the research object. The wind tunnel test of rigid tower synchronous pressure measurement was carried out on the grouped towers. Based on the time history of fluctuating wind pressure on the tower surface with different wind direction angles, the correlation between fluctuating wind pressure at different measuring points is studied, the correlation between wind pressure spectrum at key measuring points and the spectrum of circumferential overall resultant force is analyzed, and the power spectrum disturbance characteristics of circumferential overall resistance (along wind resultant force) and lift (across wind resultant force) are compared. Based on the test data, the fitting expression of power spectrum of the wind pressure and the resultant force at key points are developed. The results of spectrum analysis indicate that interference will increase the lift power spectral density in the sensitive area of the structure, and that the interference caused a certain degree of dynamic amplification effect needs an attention. The research strategies and conclusions of this paper on fluctuating wind pressure interference can provide a reference for the analysis of aerodynamic effects of similar grouped buildings/structures.