Measurement, modeling and simulation of wind turbulence in typhoon outer region

Abstract

Typhoon is one of the most destructive natural hazards, causing tremendous economic loss and fatalities every year all over the world. High-frequency wind observing tools have been deployed in many projects, which have been utilized in many recent studies to obtain data on typhoon winds, as well as turbulence. This study utilized field measurement data from the Xihoumen Bridge health monitoring system and examined the wind characteristics over water terrain at single point from four typhoons when their outer regions passed the bridge. This study firstly reviews the typhoon structure, which consists of two airflow circulations in horizontal and vertical directions. Results of this study suggest that the near ground wind turbulence characteristics should be analyzed for both directions separately. Next, the turbulence intensity, length scale, spectrum, and non-Gaussian features (skewness and kurtosis) are presented. Correlations among these parameters are also analyzed, and simplified mathematical models are introduced to quantify the correlation among various turbulence characteristics. Then, a Hermite-model based translation function method is used to simulate the non-Gaussian turbulences for different typhoon configurations. Gaussian turbulence neglecting skewness and kurtosis is also generated, and the comparison shows that non-Gaussian turbulence tends to have larger extreme gusts.