Urban Interference Effects on the Aerodynamic Loads of a CAARC High-Rise Building: A Comparative RANS and DDES Study

Urban densification and high-rise buildings alter local wind flows, thereby affecting structural aerodynamic loads. To address this issue, the present numerical study investigates the insertion of a standard high-rise building within the Oklahoma City urban dataset. Computational Fluid Dynamics simulations were conducted across eight wind incidence angles (from 0° to 360° at 45° intervals) using two turbulence models, the Reynolds-Averaged Navier-Stokes (RANS) with k-ω Shear Stress Transport closure equations and the hybrid approach Shear Stress Transport Delayed Detached-Eddy Simulations (SSTDDES). A numerical validation was conducted using the Michelstadt experimental dataset, showing that both turbulence models achieved satisfactory statistical agreement with wind tunnel data. Structural forces were quantified using aerodynamic coefficients, and the results demonstrate that while the surrounding neighborhood provides a shielding effect, it simultaneously induces complex wakes that amplify localized peak lateral forces and torsion. Notably, the SSTDDES model captured higher peak structural loads and gusts compared to the RANS approach, concluding that domain-averaged criteria can obscure severe localized hazards, emphasizing that safe high-density developments require adequate turbulence models and site-specific aerodynamic investigations.