Influence of Initial Boundary Layer on the Two-Dimensional Turbulent Mixing of a Single Stream
Influence of Initial Boundary Layer on the Two-Dimensional Turbulent Mixing of a Single Stream

Author: R. C. Bauer

Publisher:

Published: 1971

Total Pages: 47

ISBN-13:

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An integral method is presented for estimating the influence of an initial boundary layer on the development of a two-dimensional, isobaric, turbulent, free shear layer. The basic equation is derived by applying the principle that, at any streamwise station along the free shear layer, the momentum of the entrained flow equals the total axial turbulent shear force acting along the dividing streamline. This equation is solved using a single parameter family of velocity profiles derived by Korst and Prandtl's mixing length concept for turbulent shear stress. The theory involves one empirical constant which was evaluated using Tollmien's experimental data for incompressible, turbulent mixing. The theory is verified by comparing with experimental data for free-stream Mach numbers up to 6.4. (Author).

The Growth of the Two Dimensional Mixing Layer from a Turbulent and Non Turbulent Boundary Layer
The Growth of the Two Dimensional Mixing Layer from a Turbulent and Non Turbulent Boundary Layer

Author: F. K. Browand

Publisher:

Published: 1978

Total Pages: 35

ISBN-13:

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The effect of the initial boundary layer upon the downstream growth of the turbulent mixing layer between two streams is studied experimentally. Two streams are studied experimentally. Two conditions are carefully documented--in one case the boundary layers at separation are laminar; in the other case one boundary layer is made turbulent with a trip wire. When the boundary layer is turbulent, the lateral length scale, theta, characterizing the thickness of the mixing region, grows more slowly. At 400-500 initial momentum thicknesses downstream, the growth rate relaxes toward--but does not meet--the growth rate of the untripped mixing layer. The lateral distributions of turbulence quantities, when scaled with the local lateral thickness, achieve the same form at distances beyond approximately 800 momentum thicknesses. (Author).