1985 Volume 51 Issue 472 Pages 4146-4154
Time-mean and fluctuating forces acting on two rectangular prisms of the same dimension in tandem arrangement placed vertically in a turbulent boundary layer were investigated experimentally. The results were summarized in several figures from which one can obtain the time-mean drag, the fluctuating drag, the fluctuating lift and the Strouhal number for the various distances between the two prisms. Further, phase relationships between the fluctuating lift and the fluctuating pressure of the two prism were presented and discussed. The vortex shedding from the downstream prism was triggered by the arrival of the vortices from the upstream prism when the distance between the two prisms exceeds 2.5 times of the prism width. The phase shift between the fluctuating lift acting on the two prisms was found to be proportional to the distance between the two prisms.