Three-Dimensional Curved Wall Jets

Abstract

This paper presents an experimental investigation of mean velocities of turbulent, three-dimensional incompressible air jets from various rectangular orifices issuing tangentially to and flowing along the surface of a curved wall into quiescent ambient air. An experimental study of the jet separation is also presented. The three-dimensional curved wall jet is found to be drastically different in its mean property behavior from its so-called two-dimensional counterpart. Velocity contour plots show the resultant effect on the jet flow of two diverging tendencies—the free jet flow and the Coanda flow. This effect is found to occur earlier with smaller aspect-ratio orifices. Within the range of variables studied, three-dimensional curved wall jets may be characterized by three regions of maximum velocity decay. The rate of maximum velocity decay is dependent on orifice aspect ratio, except in the potential core region. Further, the curved wall jet differs from other three-dimensional jet flows in its growth behavior.