MANAGEMENT OF A PLANE TURBULENT WALL JET BY THE LARGE-EDDY BREAK-UP DEVICE(Wall Jet and Wall Flow)

Abstract

Large Eddy Break-up Device (LEBU) was applied to flow management of a plane turbulent wall jet. LEBU was located at three different distances from the wall and the mean velocity, Reynolds shear stress profiles and the wall shear stress were measured. The experimental data show that LEBU reduces development of thickness of the shear layer and magnitude of Reynolds shear stress. The wall shear stress tends to be reduced even if LEBU is placed in the outer layer. These effects are largest when LEBU is placed at the height where the turbulent production term reaches its maximum. Length scale of the large-eddies is reduced in manipulated flows, especially, in the spanwise direction.