Turbulence Structures Downstream of a Localized Injection in a Fully Developed Channel Flow

Abstract

The effects of localized blowing through a porous strip on a turbulent channel were studied experimentally. The measurements were conducted downstream of the porous strip for three blowing rates: 3%, 5%, and 8% (of the velocity at the centerline of the channel). It was found that the injection affects several turbulence parameters. Indeed, blowing decreases the skin friction while it increases the turbulence intensities and the Reynolds stresses. A study of cross-correlations in the streamwise and spanwise direction’s showed that both inclination angles in the (x,y) and (x,z) planes were increased with blowing.