Numerical Validation of Wind Effects on Tall Buildings Using the CAARC Benchmark Model Under Indian Atmospheric Boundary Conditions

Rapid urbanization and population growth in India over the past few decades have accelerated the construction of tall buildings, increasing the importance of accurately evaluating wind-induced effects to ensure structural safety, serviceability and occupant comfort. The wind tunnel testing remains a benchmark approach for evaluating wind effects on tall buildings, but its high cost and experimental complexity have encouraged the adoption of Computational Fluid Dynamics (CFD) as a practical and efficient alternative. This study investigates wind flow around the CAARC (Commonwealth Advisory Aeronautical Research Council) standard tall building model (101.6 mm x 152.4 mm x 609.6 mm), a widely accepted benchmark in wind engineering. The atmospheric boundary layer for Indian terrain was modelled using a power-law wind profile with a basic wind speed of 55 m/s at the reference height of 10 m. The CFD simulations are performed in ANSYS using the standard k–ε turbulence model and validated against benchmark data at the principal wind incidence angles (0° and 90°), where reliable experimental and code-based reference data are available. The peripheral pressure coefficients at 2H/3 showed excellent agreement with the benchmark and published data, with a maximum deviation of only 3.4% on the façade and an almost complete overlap of the pressure coefficient distributions at all other locations. At a 0° wind incidence angle, the predicted pressure coefficients on Faces A, B, C, and D are 0.8, -0.5, -0.8, and -0.8, respectively. demonstrating the reliability of the CFD model. The consistency with reference data demonstrates the capability of the adopted CFD methodology to predict wind-induced pressures and flow behaviour around tall buildings accurately. The validated method can be used for future studies on complex building geometries and wind-resistant design under Indian atmospheric conditions. Furthermore, the validated CFD model predicted a drag force of 1.62 N, with mean and peak pressures on the façade of 10.68 Pa and 20.33 Pa, respectively.