Experimental and Numerical Investigation of Localized Wind Effects from Terrain Variations at a Coastal Bridge Site

Terrain conditions may significantly affect the near-ground-layer wind speed in coastal areas. In this research, wind tunnel tests and computational fluid dynamics (CFD) were performed to investigate the impact of topographic changes on the local wind field at coastal bridge sites. Considering the geographic information system (GIS) information of an offshore bridge site, a 1:1000 topographic model was constructed to conduct tests in the wind tunnel lab under different wind directions. The influences of terrain conditions on localized wind characteristics such as the wind speed and wind attack angle under different test conditions were obtained. The results show that the wind angle varied between −6° and 6° under different conditions. To more comprehensively show the radius of influence on the local terrain, a CFD simulation was conducted. To verify the results of the wind tunnel tests, the SST k-ω model was compared and selected for simulation in this research. The influence radius of localized wind characteristics was determined by CFD simulation. The results indicate that the original topography showed “reverse amplification” on the leeward side, resulting in complex wake flows. These results may provide a reference for the design of wind-resistant structures such as bridges and offshore wind turbines in coastal areas.