Turbulent wall jets with and without an external stream

Abstract

The results are presented of experiments on wall jets in still air on flat and curved surfaces, and beneath an external stream in presence and absence of pressure gradient and initial boundary layer. It is found that the Reynolds shear stress is not zero at the velocity extrema, invalidating the simple assumptions of layer independence made by other workers: it is concluded that a satisfactory calculation method is not immediately practicable. The behaviour of wall jets is discussed in some detail on the basis of the experimental results.