Wind effects on two tandem cooling towers with spacing L^*=1.5

Two grouped cooling towers are widely constructed in China and around the world. The research on wind effects on two closely-spaced tandem large cooling towers is not only of practical significance in guiding related structural design, but can also helpfully fill up the scientific void of related fluid physics in trans-critical Reynolds number (Re) regime. Based on the engineering background of two 167-m height smooth-walled large cooling towers located at Peng-cheng electric power station in Xu-zhou City, China, the present study focuses on flow physics concerning two tandem cooling towers with spacing L^* = 1.5 (L^* = L/D, in which L is the spacing between the centers of the two cylinders and D is the diameter of the cylinder) at Re ≈ 6.5e7 employing both physical experiments (the full-scale measurement and the wind tunnel test) and numerical simulations. A data fusion approach is utilized to synthesize different schools of physical experimental data, and numerical analyses are undertaken to accurately reproduce the realistic flow pattern by calibrating the simulated wind load distributions to the physical experimental results. It is found that the fluid structure concerning the present case belongs to the bi-stable flow, for which the re-attachment phenomenon and the co-shedding phenomenon appear intermittently. Therefore, the dynamic structural responses to the corresponding periodic loadings should be checked by practicing engineers to prevent the resonance in structural design of two closely-spaced cooling towers. © The Author(s) 2025.