Computational Investigation of Wind-Induced Local Pressure Characteristics of Tapered Tall Buildings under Indian Terrain Conditions

The growing demand for tall buildings in urban environment has increased concern about wind-induced effects. Aerodynamic optimization plays a critical role in minimizing these impacts and improving structural performance. The tapering of structure is an ancient technique of wind load reduction and continues to play an important role in modern shape optimization. This study evaluates the aerodynamic performance of a scaled prismatic high-rise building model (Model A: 200 mm x 200 mm plan, 0.5 m height) against a tapered counterpart (Model B: width reducing from 200 mm at the base to 100 mm at the top), using local pressure coefficients as the primary performance metric. Transient CFD simulations were performed in ANSYS under an atmospheric boundary layer representative of Indian terrain conditions, modelled via a power-law wind profile with a basic wind speed of 55 m/s at a 10 m reference height, across seven wind incidence angles (0° to 90° in 15° increments). The k-ε turbulence model with standard wall functions was employed to resolve the near-wall flow behaviour around the building model. As wind angle increases, pressure shifts from Face A to Face C, causing asymmetric flow and separation, with strong suction up to -6.48 Pa at high angles. Drag peaks at 1.27 N (30°), while lift drops from 0.27 N (15°) to -0.28 N (75°), indicating critical wind effects. The tapered Model B reduces the peak wind pressure by 3.75% and the mean wind pressure by nearly 12.6% on the façade, compared to the prismatic Model A. The findings hold practical significance for designers working on tapered high-rise buildings in Indian terrain.