Leveraging LES data to investigate pressure peaks on high-rise buildings in neutral atmospheric boundary layers

High-rise buildings in a neutral Atmospheric Boundary Layer (ABL) can experience significant negative pressure peaks near the upper-rear corner of their leeward facade. Several wind tunnel experiments have investigated these peak phenomena through high-resolution pressure measurements, and the associated pressure magnitude has been characterized successfully. However, the physics behind the formation of these peaks is not yet fully understood.

This work aims to validate an LES simulation of the flow about a high-rise building against experimental data and then leverage it to understand the physics driving pressure peak events. A synthetic, divergence-free turbulence generator is used to achieve an incoming ABL for the LES that matches experimental data. The pressure predicted over the surface of the building by the LES agrees well with the experimental data in terms of pressure mean, rms, and peak values.

The validated LES simulation is finally used to study peak events for the case of an incoming ABL with a wind direction of 20°. The instantaneous flow field in the vicinity of peak events is visualized and it is shown how eddies sheddeded from the shear layers on top of the roof of the building interact with edge separations to form the observed pressure peaks.