Experimental and Computational Simulation of an Open Terrain Wind Flow around a Setback Building using Hybrid Turbulence Models

In recent days, building aerodynamics has gained more attention to urban planners, architects, and wind engineers in understanding the wind flow behaviors around tall buildings. CFD (Computational Fluid Dynamics) simulations are the major tool regularly carried out to assess the wind flow pattern around the buildings to demonstrate the atmospheric and wind tunnel environment in accordance with the turbulence parameters. One of the most challenging tasks is to evaluate a turbulence model which precisely represents atmospheric turbulence flow using computation resources. This study is intended to analyze the precision and numerical stability of open terrain wind flow around a setback building with sharp edges of aspect ratio of 1:5. Hybrid turbulence models using Delayed Detached Eddy Simulation (DDES) and Improved Delayed Detached Eddy Simulation (IDDES) are employed with (Y+) wall treatment in combination with roughness parameters. From the numerical simulation, the size of re-circulation zones in addition to wake separation zones in a threedimensional plane are determined to assess the flow characteristics of the building at 00 wind incidence. The mean pressure coefficients (CP mean) are validated against the results obtained from Boundary Layer Wind Tunnel (BLWT) experiments carried out at CSIR-Structural Engineering Research Centre, Chennai.