Three dimensional turbulent wall jets

Abstract

Abstract Jets issuing tangentially to an impermeable flat surface from orifices of finite aspect ratio are termed three‐dimensional wall jets. The turbulent flow of viscous incompressible fluid associated with such wall jets has been investigated analytically. Results are presented for the wall jets issuing from orifices of various shapes and several aspect ratios. The maximum velocity shows three regions of decay. The potential core region is followed by a characteristic decay region where maximum velocity decays in a manner dependent on the shape and aspect ratio of the orifice. Following this region, there is a radial wall jet type maximum velocity decay region. All three‐dimensional wall jets issuing from any arbitrary cross‐sectional orifice decay in a similar manner in this radial decay region. The half‐velocity width grows faster in the transverse direction than in a direction normal to the flat surface. The analytical results agree reasonably well with existing experimental results.