Velocity spectra and turbulence statistics at the northeastern coast of Taiwan under high-wind conditions

Abstract

In this paper, in situ observation and measurement of strong wind (typhoon) in the northeastern coast of Taiwan was conducted. By employing a three-axis ultra-sonic anemometer, the wind velocity and temperature time series data on a typhoon day were measured. The recorded digital data were analyzed to yield the velocity spectra and their turbulence statistics under high-wind conditions. Results show that the observed longitudinal turbulent velocity spectrum is in good agreement with the von Karman spectrum equation. Lateral turbulent velocity spectrum is also compared with the isotropic turbulence spectrum equation. The characteristics of integral scales are compared with the isotropic turbulence results, and other published field data. The contributions to the Reynolds stress of strong wind made by the four quadrant events are analyzed and discussed.