The structure of a self-preserving turbulent plane jet

TLDR: The structure of a self-preserving turbulent plane jet exhausting into a slow-moving parallel airstream is studied in this paper, where results of turbulence measurements and the structure is compared with that of the plane wake.

Abstract: The structure of a self-preserving turbulent plane jet exhausting into a slow-moving parallel airstream is studied. The investigation includes results of turbulence measurements and the structure is compared with that of a self-preserving plane wake. The results show that self-preservation is established at a distance of about thirty jet widths downstream of the jet nozzle and that, in the self-preserving region of the jet, the distributions of the turbulent intensities and shear stress across the jet are very similar to those found in the plane wake. The distribution of the intermittency factor, however, is found to be more like that found in an axi-symmetric jet than in a plane wake. The turbulent energy balance also shows important differences to that of the wake flow. The unsteady irrotational flow outside the turbulent shear layer is investigated and it is found that the experimental results agree with the predictions of the theories of Phillips (1955) and Stewart (1956). Some comments are also made on the eddy structure and the applicability of the simple theories of turbulence.