Management of a Plane Turbulent Wall Jet by the Large-Eddy Break-up Device

Abstract

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