Impact of Super High-Rise Buildings on Gust Generation in Surrounding Areas During Typhoon Landfall: Large-Eddy Simulations

Abstract

This study investigates the effects of a high-rise building complex (HB) located in the Haeundae District, Busan, South Korea on surrounding airflow patterns and gust generation using the Parallelized Large-Eddy Simulation Model Version 6.0. Numerical simulations were validated against wind speeds measured during the landfall of Typhoon Hinnamnor, which affected the Busan area in South Korea. To assess the impact of HB height, scenario experiments were conducted by varying the height from 0% to 75% of the actual height in 25% increments. Results showed that taller buildings intensified downdrafts and flow separations, significantly increasing pedestrian level mean and turbulent wind speeds. The gust factor decreased with HB height, indicating limitations when using it alone to assess gust intensity under strong wind conditions. To address this, additional analysis focusing on turbulent gusts was conducted. It revealed that gust intensity increased in densely built, lowrise areas near HB as HB height rose. Gust probability analysis indicated the occurrence of extreme gusts was very low during typhoon landfall. However, as HB height increased, frequencies of moderate and strong gusts rose in areas with intensified flow separation. These findings improve the understanding of airflow structures around high-rise buildings and demonstrate that using high-resolution large-eddy simulation techniques under extreme weather conditions can enhance the accuracy of wind hazard assessments and support evidence-based decision-making for pedestrian safety and urban resilience.