Experimental and Numerical Study of the Turbulence Characteristics of Airflow around a Research Vessel

Abstract

Airflow distortion by research vessels has been shown to significantly affect micrometeorological measurements. This study uses an efficient time-dependent large-eddy simulation numerical technique to investigate the effect of the R/V Tangaroa on the characteristics of the mean airflow and the turbulent wake. Detailed comparison is given between the numerical results and an extensive experimental dataset. The study is performed for the whole range of relative wind directions and for instruments located in regions of high and low flow distortion. The experimental data show that both the normalized wind speed and normalized standard deviation are only weakly dependent on wind speed, ship speed, ship motion, and sea state, but strongly dependent on relative wind direction. Very good agreement is obtained between the experimental and numerical data for the mean flow, standard deviation, and turbulence spectra in the wake, even in areas of strong turbulence.