CFD simulation advances in urban aerodynamics: Accuracy, validation, and high-rise building applications

• CFD analysis of airflow around an isolated high-rise building; • The simulation employed a velocity inlet condition applied through user-defined functions; • Verification, validation, and sensitivity analysis. Accurate prediction of wind loads on high-rise buildings is essential for structural safety and urban planning. This study leverages Computational Fluid Dynamics (CFD) to analyze airflow around an isolated high-rise building, integrating aerodynamic optimization, rigorous verification/validation, and sensitivity analyses. A grid convergence study identified an optimal mesh resolution of 1.96 million cells (RNG-2), achieving close agreement with wind tunnel benchmarks: rooftop reattachment length (XR/b = 0.55 vs experimental 0.52) and wake reattachment length ((XF/b = 3.75)). The RNG k-ε turbulence model with second-order discretization delivered superior accuracy, yielding a mean velocity RMSE of 0.126 and R² = 0.972. Comparative evaluations of AIJ and COST guidelines underscored the impact of boundary conditions, while turbulence model assessments revealed RNG k-ε advantages over SST k-ω and URANS in accuracy and computational efficiency. Despite advancements, challenges persist in modeling atmospheric boundary layers and complex urban geometries. This work emphasizes the need for standardized validation protocols and provides actionable insights for sustainable design, demonstrating CFD’s critical role in urban wind engineering