Experimental and numerical investigation on the aerodynamics of isolated high-rise building and phenomenology of twisted wind field

Abstract

Insufficiently studied, the phenomenon of twisted wind is prevalent in mountainous regions. This study focuses on investigating the characteristics and aerodynamics of a single high-rise building subjected to a twisted wind field (TWF). By comparing the 0° conventional wind field (CWF) with two TWFs (TWF15 and TWF 30) with maximum twisted angle of 15° and 30°, both wind tunnel testing and computational fluid dynamics (CFD) are employed. A comprehensive analysis is conducted to examine the differences between TWFs and CWF in terms of wind profiles, turbulence, aerodynamic characteristics of single high-rise buildings, and wake vortex morphology. The results demonstrate notable disparities between TWF and CWF. Particularly, the twisted wind induces inflection in the wind profile, leading to significant acceleration or deceleration. Moreover, the twisted effect generates an asymmetric distribution of average building surface pressure, thereby introducing the potential for asymmetric or torsional loading extremes. Phenomenologically, the twisted effect weakens shear layer separation, creates squeezed separation bubbles, and promotes premature reattachment, resulting in distinct flow field morphologies compared to CWF. Furthermore, as the wind twisted angle increases, the energy concentration associated with Bernard-Karman shedding diminishes, thereby significantly altering the wake characteristics.

Keywords

• Twisted wind
• wind tunnel test
• CFD
• high-rise buildings
• bluff-body aerodynamics