Effect of the combined aerodynamic control on the amplitude characteristics of wind loads on a tall building

Experimental investigation of the amplitude characteristics of wind loads on a square cross-sectional tall building under the combined aerodynamic control, which consists of the shape modification and air suction, has been conducted, and the effects of the suction flux coefficients CQ and wind direction angles on the wind pressure coefficients and aerodynamic force coefficients of five test models (includes a square cylinder and its corner modifications such as recession and chamfer, tapered cylinder and Y-shaped cylinder, and they are denoted as the Models 1-5 respectively) with and without air suction control have been analyzed. The Model 1 without suction control is defined as the benchmark model. The results show that the shape modifications have significant control effects on the mean and RMS pressure drag coefficients (CD and C Sigma D) as well as the RMS pressure lift coefficient C Sigma L of the Models 2, 3 and 5 at 0 degrees wind direction, with the maximum reduction rates (CDR, C Sigma DR and C Sigma LR) of 39.2%, 44.0% and 38.4% for the Models 2, 5 and 2 respectively. When compared with the benchmark model, the most significant control effects of the combined aerodynamic control on CDR, C Sigma D and C Sigma L of the Models 2-5 with the suction speed of 9 m/s are also at 0 degrees wind direction, with the maximum reduction rates of 61.8%, 65.8% and 5.7% for the Models 2, 2 and 5 respectively, which indicates that the combined aerodynamic control is more effective on the drag reduction than the passive or active aerodynamic control individually, and the Model 2 with suction control has the best wind-resistant performance. This study contributes to an effective aerodynamic measure to control the amplitude characteristics of wind loads on tall buildings, which can be an important reference for further studies or potential engineering applications of the combined aerodynamic control in mitigating the wind loads and wind-induced responses of tall buildings.