CHARACTERISTICS OF CIRCULAR CYLINDERS IN TURBULENT FLOWS.

Abstract

The effect of a free-stream turbulence of high intensity on the flow past a rigid circular cylinder was experimentally studied in a Reynolds-number range 7. 9 multiplied by 10**3 approximately 5. 4 multiplied by 10**4. Square-meshed grids were used to produce homogeneous turbulent-flow fields. The intensity and scale of a turbulent flow in which the cylinder was immersed were varied by positioning the cylinder at various locations downstream of the grid. Measurements were made of the time-averaged drag coefficient, Strouhal number of the vortex shedding, spanwise correlation length and length of the vortex formation region in the wake of the cylinder. These properties of flow around the cylinder were found to be considerably different from those measured in a smooth flow.