Large-eddy simulation of airflow dynamics around a cluster of buildings

The wind flow around the buildings with different rooftops is studied numerically using large-eddy simulation (LES). The filtered Navier-Stokes equations in LES are used to compute the large eddies, whereas the dynamic Smagorinsky subgrid-scale (SGS) model calculates the small eddies. A turbulent spot method is applied for the synthesis of artificial turbulent fields at the inlet. In this separated and reattached flow, our aim is to analyze the wakes' vortical structure along with the buildings of different heights and shapes. A large number of engineering applications involve precise predictions of the airflow around buildings to ensure performance and safety. To validate the numerical solver, a comparison is performed with the earlier reported numerical and experimental data. The turbulent flow characteristics are discussed in terms of instantaneous flow structure and time-averaged statistical flow quantities. All the cases are simulated for a Reynolds number Re = 12 , 000 to understand the turbulent airflow patterns. The flow shows a separable bubble at the leading edge of the rooftop of the building that leads to recirculation at the lee side of the first row of buildings. Due to the recirculation, the suction arises near the leading edge of the building to assure a continuous flow of air around the obstacles. Further, Reynold stresses show high momentum fluxes in the frontal region of the buildings.

Automated summary

This study investigates the wind flow around buildings with different rooftops using large-eddy simulation (LES) numerically. The LES method is used to compute the large eddies and the dynamic Smagorinsky subgrid-scale (SGS) model calculates the small eddies. Artificial turbulent fields are generated at the inlet using the turbulent spot method. The study aims to analyze the wakes' vortical structure of buildings with different heights and shapes. Precise predictions of airflow around buildings are important for various engineering applications to ensure performance and safety. The numerical solver is validated by comparing it with earlier reported numerical and experimental data. The turbulent flow characteristics are discussed in terms of instantaneous flow structure and time-averaged statistical flow quantities. The simulated cases have a Reynolds number Re = 12,000 to understand the turbulent airflow patterns. The flow exhibits a separable bubble at the leading edge of the building's rooftop, resulting in recirculation at the lee side of the first row of buildings. Suction occurs near the leading edge of the building due to this recirculation, ensuring a continuous flow of air around the obstacles. Additionally, Reynolds stresses show high momentum fluxes in the frontal region of the buildings.