Characteristics Of Wind Field Near The Ground Offshore Typhoon In The South China Sea

This article uses the44coastal and offshore wind tower calculated the turbulenceintensity, the gust factor, and the wind vertical wind shear during the typhoon, in theSouth China Sea,, and use of the Weibull distribution, the Fisher-Tippett (extremevalue type I or Gong Bell) distribution, P-III-type distribution, calculated the50yearsmaximum wind speed in Hong Kong Waglan Island, and the Weizhou weather station.By analysis the South China Sea typhoon, select Typhoon "Hagupit" and "Dujuan" asa representative of the South China Sea to do numerical simulation. Use the measureddata to validate the simulation results. Using numerical simulation output analysis thetyphoon wind speed time series, vertical wind profile10-100m wind speed-timeevolution of grid points. The main conclusions are as follows:1. During typhoon the turbulence intensity decreases by increasing height, theturbulence intensity in the center and near of typhoon is greater than the turbulenceintensity of the typhoon peripheral. From sea to land, the turbulence intensity isincreasing.2. During typhoon the gust factor decreases by increasing height. Low-level (10m and30m height), the gust factor in the center and near of typhoon is greater thanthe typhoon periphera. High-level (50m and70m height), the gust factor in the centerand near of typhoon is less than the typhoon periphera. From sea to land, the gustfactor is increasing.3. During the typhoon near-surface wind speed increases in increasing height.From sea to land, the wind shear index is increasing.4. The maximum wind speed of50years of Hong Kong Waglan Island andWeizhou weather station were calculated by using the Weibull distribution, Gumbeldistribution, P-III distribution. The best calculation results of was calculated by theWeibull distribution: The maximum10-minute wind speed in50years of WaglanIsland, Hong Kong was47.1m/s,The10-minute mean maximum wind speed ofWeizhou weather station in50years was29.8m/s. 5. According to the typhoon path and strength characteristics of the South ChinaSea, selected the typhoon Hagupit to represent Yangjiang and Zhanjiang landingtyphoons and selected the typhoon Dujuan to represent the eastern Guangdong, thePearl River landing typhoons, and using WRF mesoscale model system to do simulatetests. The simulation results between the realily of Hagupit typhoon path, structure,wind speed was on agreement, The simulation typhoon path of Dujuan move morenortherly at beginning, but before landing th path and live was basically the same. Sothe simulated typhoon structure, the wind speed can be used to calculate the offshorewind farm extreme wind conditions.