Calibrated consistent flow generator for tall building aerodynamics using large eddy simulation

Abstract

Ensuring proper matching of the target wind characteristics of the inflow is vital for the accuracy of both experimental and numerical wind studies. In the current study, a calibrated turbulent inflow generation technique was developed to accurately simulate the inflow boundary condition for large eddy simulation (LES) of the lower region of the atmospheric boundary layer (ABL) based on a newly developed technique, namely consistent discrete random flow generator (CDRFG). The proposed technique, namely Calibrated-CDRFG (C-CDRFG), targets specific incoming turbulence at distances downstream to account for dissipation of the turbulent kinetic energy. The proposed technique generates accurate turbulent velocities with proper turbulence intensity, spectra, coherency, and correlation at the target distance downstream for a range of terrain conditions. The technique was validated by evaluating the wind-induced loads and responses for the Commonwealth Advisory Aeronautical Research Council (CAARC) and comparing that to the existing wind tunnel (WT) wind-induced response for the angle of attack (AOA) ranging between 0° and 90°. It was found that the resulting wind-induced response from the C-CDRFG technique resulted in an average matching of 91% of the wind tunnel results. The proposed technique is believed to be computationally efficient, flexible, and easy to be sustainable for parallel computing environments and thus provides significant value for Large Eddy Simulation (LES) wind engineering applications.

Keywords

• Turbulent inflow
• Wind spectra
• Response spectra
• Coherency
• Wind-induced response
• Tall building