Study on formation of spatial correlation of fluctuating lift forces acting on rectangular cylinder under weak periodic disturbance

摘要

In this paper, the spatial correlations of the fluctuating wind velocity and that of fluctuating lift force acting on the flat rectangular cylinder whose width/depth ratio, B/D, was 13, were investigated in some grid turbulence flows. As the result of this investigation, it was found that the integrated scale of spatial correlation of fluctuating lift force was expanded as approximately 10 times as that of the fluctuating wind velocity. It became clear that the fluctuating pressure around the reattaching region made high spatial correlation of fluctuating lift force, as the result of investigation of the divided spatial correlation of lift. Furthermore, to consider the formation process of spatial correlation of fluctuating lift force, the weak periodic disturbance was given around the stagnation point on the upwind surface. As the result of this study, it was clarified that the expanded spatial correlation of fluctuating lift force was made by the flow around the reattaching region of the separated flow.