Some Effects of Free-Stream Turbulence on the Flow Past a Cantilevered Circular Cylinder

Abstract

Flow around a cantilevered circular cylinder has been studied experimentally in the subcritical and critical Reynolds-number ranges. Particular attention was paid to the free-stream turbulence effects on the steady aerodynamic characteristics of the cylinder. Measurements were made of the surface pressure distribution, flow separation line and vortex shedding frequency in gridgenerated turbulent flows. The aerodynamic characteristics of a cylinder were only minutely affected by the free-stream turbulence in the subcritical flaw. The critical Reynolds number was expressed as a function of the Taylor number Tx defined in terms of the longitudinal integral scale of the free-stream turbulence. The mean drag coefficient and the position of the flow separation point were fairly well-correlated with the parameter Re1.34.Tx, with Re being the Reynolds number. Furthermore, it was found that some steady aerodynamic coefficients of the cylinder were closely correlated among themselves.