Accession Number : ADA019552

Title :   Further Refinement of the Turbulence-Model Transition-Prediction Technique.

Descriptive Note : Interim rept. 15 Jul 74-15 Jul 75,

Corporate Author : DCW INDUSTRIES SHERMAN OAKS CALIF

Personal Author(s) : Wilcox,D. C. ; Chambers,T. L.

Report Date : JUL 1975

Pagination or Media Count : 81

Abstract : Various aspects of a turbulence-model-transition-prediction method have been analyzed. The primary aims of the research have been to develop an understanding of the relation of model-predicted transition to the important physical processes and to improve, generalize, and further validate the model. Progress has been made in developing understanding of (1) low-Reynolds-number modifications to the turbulence generation terms and (2) the method used to simulate surface roughness effects on transition. As a result of this improved understanding, boundary conditions for the model have been revised and the model now predicts a roughness-dominated transition regime. To further validate the model, effects of pressure gradient on flat-plate boundary-layer transition have been analyzed. Generalization of boundary conditions for flows with mass injection has also been accomplished. The model has been generalized to include effects of coordinate-system rotation; the improved model accurately predicts laminarization in rotating channel flow. (Author)

Descriptors :   *Boundary layer transition, *Turbulence, Mathematical models, Mathematical prediction, Reentry vehicles, Nose cones, Turbulent flow, Viscous flow, Surface roughness, Suction slots, Flat plate models, Incompressible flow, Reynolds number

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE