The objectives of the work are two fold. Firstly, its studies the effect of a longitudinal pressure gradient on the nature of the shear stress distribution, as well as the mechanism of energy-production. Secondly, it explores to find out if the existence of pressure gradients increased, in the flow field, the size of the negative energy-production region. The flow pattern used in conducting the present experiments was composed of a half-jet blowing out of a narrow vertical slot of large aspect ratio. The jet was bounded by a smooth rigid flat wall on one side, and mixing with a slower stream of air on the free side. A convergent then divergent passage was provided for the entire flow by placing a half symmetrical Joukowski airfoil section on the free stream side of the wind tunnel. This airfoil section not only created a longitudinal variation in the free stream velocity, but also a pressure gradient which changed sign from negative in the convergent part of the passage to positive in the divergent part.