Experiments on the Circular Jet with the Uniform Flow Having Wake : Turbulence Properties

Abstract

Experimental results of the secondary flow and the turbulence properties of a three-dimensional jet injected from a hole located on the downstream side of a circular cylinder into a uniform flow with a wake or into a quiescent fluid are presented. A secondary flow, such that the cross-sections of the jet are elongated by it to the z-direction, is observed, and deformation of the jet section injected into the uniform flow are considerably larger than those of the jet injected into a quiescent fluid. The fluctuating velocity profiles of the jet injected into a quiescent fluid become a similar form at x/d≳ 63. In the jet injected into the wake, the turbulence intensity of the jet becomes smaller than those of the wake. It is clarified from the power spectra that the Karman vortex disappears as a result of the interference with the jet.