Experimental Investigation of a Laminar Two-Dimensional Plane Wall Jet

Abstract

An experimental investigation was made of a two-dimensional wall jet at low Reynolds numbers with small natural disturbances in the jet. The main characteristics of the laminar regime are in agreement with theoretical results. The stability of the flow was studied for the Reynolds number range of 270-770. Longitudinal velocity fluctuations exhibited two regions of greatest amplitude, one region on each side of the maximum velocity peak. Growth of these fluctuations was found to be in agreement with linear stability theory. The disturbance region farthest from the wall appeared to dominate the stability of the velocity profiles. A characteristic frequency of the disturbance varied directly with the local maximum velocity and inversely with the local boundary layer thickness.