Wind Turbulence Characteristics Under Typhoon Conditions

Abstract

Wind turbulence characteristics of typhoon Megi during 27–28 September 2016 were studied with the wind data obtained from an offshore met tower near Changhua, the west coast of Taiwan. Based on the 10-min average, the results are presented with the wind speed recorded, the distribution of the probability density function, turbulence intensity, power spectrum, cross-correlation function, auto-correlation function. First, both of the power spectra of the wind data obtained at the heights 50 m and 86 m show a good agreement with the Von Karman model. Second, cross-correlation analysis of the wind data at the heights 50m and 86 m show that 85% of the time during the typhoon period the correlation coefficients were lower than 0.2, and the rest 15% of the time the correlation coefficient could reach 0.55. These observations provide important information about the wind characteristics of the boundary layer near the surface under a typhoon condition. The results are expected to be useful in the considerations in the design of offshore structures near the west coast of Taiwan.