Fluctuating forces on a rectangular prism and a circular cylinder placed vertically in a turbulent boundary layer

An experimental study was conducted to investigate the fluctuating force generated by the shedding of vortices from a three-dimensional bluff body placed vertically in a turbulent boundary layer. A conventional strain-gauge balance was modified and used in the experiment. The balance used has a relatively high natural frequency and gives a linear relation between force and strain. Prisms with a square cross section and circular cylinders were selected as three-dimensional bodies varing in aspect ratio and height. The aspect ratio and the ratio of the height to the boundary layer thickness were varied in the measurement of the fluctuating force on a body.