Measurement and analysis of the surface layer wind field characteristics of violent typhoon "Utor"

Based on an anemometer tower located in a coastal region where typhoons frequently attacked, a field measurement study on wind field characteristics during typhoon "Utor" was performed and was presented in this paper. Time-histories of wind speed, wind direction and wind pressures were collected. Through analyzing the measured data, it is found that, the instantaneous maximum wind speed is 37. 05 m/s at 10 m height and the maximum mean wind speed for 10-minutes time interval is 26. 31 m/s, respectively during the typhoon. Also, the mean wind speed and mean wind direction for 10-minutes time interval during the typhoon are obtained. The turbulence characteristics of fluctuating wind were then analyzed. Combined with empirical formula, the correlation between gust factor and turbulence intensity was discussed and the correlation was fitted. The power spectrum of downwind speed was studied and compared with other empirical spectra. It is found that the measured spectrum is most consistent with the Karman spectrum.