COMPREHENSIVE ASSESSMENT OF WIND-INDUCED INTERFERENCE CRITERIA ABOUT LARGE COOLING TOWERS WITH TYPICAL SIX-TOWERS DOUBLE-COLUMNS ARRANGEMENTS

IFs (Interference Factors) were proposed under various criteria to quantify wind-induced interference among grouped cooling towers and to amplify wind pressure loadings. However, those parameters seem to be very discrete in values for different evaluation criteria. Aiming to study interference effects under complex tower group combination, cooling tower groups with typical six-tower double-column arrangements were selected to conduct case studies by wind tunnel tests and FEM calculation, investigating the interference effects among classical rectangular and rhombic arrangements considering several commonly-used central distances among towers. IFs of 25 kinds were compared based on three types of index levels, namely aerodynamic loading, internal force and reinforcement ratio, respectively. Wind pressure measurements with 15×16 incoming flow conditions for the 1:200 reduced-scale model were carried out in TJ-3 wind tunnel, corresponding 3-D dynamic or static calculations and reinforcement design under 20 loading combination cases were also performed to analyze IFs. The principal conclusions can be summarized as follows: sensitivity of fluctuation about IFs in loading level would be the largest, while those in force level are medium, and those in reinforcement level are the smallest; there are great distinctions about IFs' values for different criteria, whose maximum may reach 49% over the average value; the worst wind directions and interference effects are greatly influenced by the arrangement of tower groups, and the towers in windward location under the rectangle arrangement and those in leeward location under the rhombus arrangement are in the worst loading states; the towers under the rhombus arrangement suffer more interference actions than those under rectangular combination in general.