Large-eddy simulation of interference-induced aerodynamic characteristics and flow dynamics around a high-rise building

Abstract

Aerodynamic interference among high-rise buildings can substantially alter surface pressures and unsteady wind loads in urban environments. This study investigates the interference effects induced by an interfering building on a principal tall building using a validated large-eddy simulation framework benchmarked against wind tunnel measurements. Representative configurations involving lateral offset, rotation angle, and height ratio are examined through pressure interference factors, flow-field distribution, power spectral density (PSD), and proper orthogonal decomposition (POD). Results show that mean pressure interference is mainly expressed as large-scale pressure redistribution, with the maximum absolute mean pressure interference factor reaching approximately 2.0. In contrast, root mean square (RMS) pressure interference is more localized near the windward-edge and adjacent side-face regions, with the maximum RMS pressure interference factor reaching approximately 3.0. Lateral offset configuration promotes asymmetric wake-edge exposure and enhances pressure fluctuations near the exposed region of the windward face and the adjacent lateral face. Building rotation redistributes the wake trajectory and pressure-interference pattern, while similar mean wake patterns may exhibit substantially different temporal coherence and pressure spectra. The height ratio of the interfering building governs the vertical transition from roof-level overflow impingement to wake-dominated shielding. POD analysis shows that the leading coherent mode contributes up to 42.2% of the fluctuation energy in the lateral-offset cases. Together with PSD results, this indicates that localized pressure amplification is governed primarily by low-frequency coherent wake motions rather than spatially uniform random turbulence amplification. These findings reveal the underlying mechanism by which geometric interference reorganizes coherent wake motions and induces localized aerodynamic amplification.