A new time scale based k-epsilon model for near wall turbulence

Technical Report · Tue Sep 01 04:00:00 EDT 1992

OSTI ID:6997379

Yang, Z; Shih, T H

A k-epsilon model is proposed for wall bonded turbulent flows. In this model, the eddy viscosity is characterized by a turbulent velocity scale and a turbulent time scale. The time scale is bounded from below by the Kolmogorov time scale. The dissipation equation is reformulated using this time scale and no singularity exists at the wall. The damping function used in the eddy viscosity is chosen to be a function of R(sub y) = (k(sup 1/2)y)/v instead of y(+). Hence, the model could be used for flows with separation. The model constants used are the same as in the high Reynolds number standard k-epsilon model. Thus, the proposed model will be also suitable for flows far from the wall. Turbulent channel flows at different Reynolds numbers and turbulent boundary layer flows with and without pressure gradient are calculated. Results show that the model predictions are in good agreement with direct numerical simulation and experimental data.

• Research Organization: National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center
• OSTI ID: 6997379
• Report Number(s): N-92-32868; NASA-TM--105768; ICOMP--92-11; CMOTT--92-07; E--7194; NAS--1.15:105768; CNN: NASA ORDER C-99066-6; RTOP 505-62-21
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
BOUNDARY LAYERS
COMPARATIVE EVALUATIONS
DAMPING
EVALUATION
FLOW MODELS
FLUID FLOW
INCOMPRESSIBLE FLOW
LAYERS
MATHEMATICAL MODELS
PRESSURE GRADIENTS
REYNOLDS NUMBER
SHEAR
TURBULENCE
TURBULENT FLOW
VELOCITY
VISCOSITY