Nearfield Evolution of a Longitudinal Vortex Generated by an Inclined Jet in a Turbulent Boundary Layer

Abstract

The nearfield evolution of a longitudinal vortex embedded in a turbulent boundary layer was examined in a wind-tunnel test. The Vortex was produced by an inclined round jet, the diameter of the jet being 0.4δ0.99 . Flow properties were measured at a freestream velocity of 20 m/s using a laser Doppler anemometer. Control parameters are jet skew and pitch angles, and speed ratio. It was observed that a single vortex is generated at x = 10D. The effects of the control parameters on the strength and location of the vortex were examined. For an embedded vortex and favorable velocity distribution, the test results suggested a skew angle of 60 deg, a pitch angle of α = 30 deg, and speed rations of γ = 1.0. The study provided insight into the flow physics and a database.