Experimental study of a turbulent boundary layer flow over a windbreak of semi-circular section

In this paper, measurements and analysis of the turbulence characteristics for a turbulent boundary layer flow over windbreak of semi-circular section are reported. Results indicate that the decay of the maximum Reynolds stress reduction downstream of the windbreak is more rapid than that of the maximum mean wind speed reduction. The turbulent velocity profiles downstream of the windbreak can be collapsed to a similarity profile if the proper characteristic scales are adopted. Analysis of the Reynolds stress structure behind the windbreak shows that the ejection and sweep events contribute mostly to the stress. The stress fraction difference between sweep and ejection is well related to the turbulent velocity skewness coefficient.