Insights into the Transcritical Reynolds Number Range Based on Field Measurements of a Wind Turbine Tower

The estimation of vortex shedding load is essential for the prediction of Vortex-Induced Vibration (VIV) on slender bodies. The application of the VIV model to a full-scale slender tower, such as wind turbine towers and chimneys, depends on the estimation of actual vortex shedding load under field conditions. This paper aims to provide insight on the vortex shedding spectrum with a real-life wind and the transcritical flow-regime, which requires high effort to observe in the wind tunnel scale. The vortex shedding spectrum is evaluated from the response measurement is focused on this paper, where challenges from the investigation and an introduction to the wind pressure measurement are then discussed. Global Strouhal number at high Reynolds numbers, spectrum of tower response in lift direction, and the estimation of critical velocity are presented. The influence of ambient condition such as wind profile, wind direction and turbulence intensity are included.