Variations in gust factor with wind direction and height based on the measurements from a coastal tower during three landfalling typhoons  

作　　者：Pingzhi Fang Tao Huo Junjun Pan Guihan Luan 

机构地区：[1]Shanghai Typhoon Institute of China Meteorological Administration,Shanghai,China [2]Asia-Pacific Typhoon Collaborative Research Center,Shanghai,China [3]China Construction Eighth Engineering Division Corp.,LTD.,Shanghai,China [4]Aolai Guoxin(Beijing)Testing Technology Corp.LTD.,Beijing,China

出　　处：《Tropical Cyclone Research and Review》2024年第3期187-195,共9页热带气旋研究与评论（英文版）

基　　金：supported by the National Key R&D Program of China (Grant No.2023YFC3008501);the Shanghai Science and Technology Commission Project (Grant No.23DZ204701);the Science and Technology Research and Development Project of China Construction Eighth Engineering Division Corp.,LTD. (Grant No.2022-Q-03).

摘　　要：Using high-frequency onshore wind data from four different heights of a coastal tower,the variations in gust factor with turbulence intensity,height and wind speed were studied under typhoon conditions.The gust factor increases with increasing turbulence intensity and,most often,can be described by a linear relationship with the turbulence intensity.The gust factor decreases with height and is relatively small compared with those presented in the national codes and other studies.A value of 2.5 is acceptable for the peak factor,which is close to the recommended value of the national code in China.The gust factor increases with increasing wind speed and is also affected by the wind direction.The gust factor has a value to that of previously published results when the wind flows roughly perpendicular to the shoreline,and has a smaller value when the wind flows roughly parallel to the shoreline.The phenomenon is caused by the confinement of shoreline on the sea wave development.Sea waves tend to propagate normal to the shoreline because of the refraction effect.As a result,a shorter roughness length exists in the parallel direction to the shoreline.It can be further explained by the weakness in the momentum flux exchange between the air and sea based on the wave form drag theory when the wind flows parallel to the shoreline.

关 键 词：Gust factor Landfalling typhoon Peak factor Roughness length Wind direction 

分 类 号：P444[天文地球—大气科学及气象学]