scholarly journals A Low-Reynolds-Number k-.EPSILON. Model Reflecting Characteristics of a Reynolds Stress Model.

1995 ◽  
Vol 61 (585) ◽  
pp. 1714-1721 ◽  
Author(s):  
Ken-ichi Abe ◽  
Tsuguo Kondoh ◽  
Yasutaka Nagano
Keyword(s):  
Reynolds Number ◽  
Reynolds Stress ◽  
Low Reynolds Number ◽  
Reynolds Stress Model ◽  
Stress Model ◽  
Low Reynolds

scholarly journals Computation of Turbulent Heat Transfer on the Walls of a 180 Degree Turn Channel With a Low Reynolds Number Reynolds Stress Model

2002 ◽  
Author(s):  
D. L. Rigby ◽  
A. A. Ameri ◽  
E. Steinthorsson
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Reynolds Stress ◽  
Low Reynolds Number ◽  
Reynolds Stress Model ◽  
Turbulent Heat Transfer ◽  
Turbulent Heat ◽  
Stress Model ◽  
Generalized Gradient ◽  
Low Reynolds

The Low Reynolds number version of the Stress-ω model and the two equation k-ω model of Wilcox were used for the calculation of turbulent heat transfer in a 180 degree turn simulating an internal coolant passage. The Stress-ω model was chosen for its robustness. The turbulent thermal fluxes were calculated by modifying and using the Generalized Gradient Diffusion Hypothesis. The results showed that using this Reynolds Stress model allowed better prediction of heat transfer compared to the k-ω two equation model. This improvement however required a finer grid and commensurately more CPU time.

A Reynolds-Stress Model for Near-Wall and Low-Reynolds-Number Regions

1988 ◽  
Vol 110 (1) ◽  
pp. 38-44 ◽  
Author(s):  
Nobuyuki Shima
Keyword(s):  
Reynolds Number ◽  
Reynolds Stress ◽  
Present Model ◽  
Transport Model ◽  
Low Reynolds Number ◽  
Reynolds Stress Model ◽  
Turbulence Energy ◽  
Stress Model ◽  
Low Reynolds ◽  
Near Wall

The Reynolds stress model for high Reynolds numbers proposed by Launder et al. is extended to near-wall and low-Reynolds-number regions. In the development of the model, particular attention is given to the high anisotropy of turbulent stresses in the immediate vicinity of a wall and to the behavior of the exact stress equation at the wall. A transport model for the turbulence energy dissipation rate is also developed by taking into account its compatibility with the stress model at the wall. The model and the low-Reynolds-number model of Hanjali’c and Launder are applied to fully-developed pipe flow. Comparison of the numerical results with Laufer’s data shows that the present model gives significantly improved predictions. In particular, the present model is shown to reproduce the sharp peak in the distribution of the streamwise turbulence intensity in the immediate vicinity of the wall.

Contribution towards a Reynolds-stress closure for low-Reynolds-number turbulence

1976 ◽  
Vol 74 (4) ◽  
pp. 593-610 ◽  
Author(s):  
K. Hanjalić ◽  
B. E. Launder
Keyword(s):  
Reynolds Number ◽  
Shear Stress ◽  
Reynolds Stress ◽  
Dissipation Rate ◽  
Numerical Solutions ◽  
Low Reynolds Number ◽  
Transport Processes ◽  
Turbulent Shear ◽  
Turbulent Shear Stress ◽  
Low Reynolds

The problem of closing the Reynolds-stress and dissipation-rate equations at low Reynolds numbers is considered, specific forms being suggested for the direct effects of viscosity on the various transport processes. By noting that the correlation coefficient$\overline{uv^2}/\overline{u^2}\overline{v^2} $is nearly constant over a considerable portion of the low-Reynolds-number region adjacent to a wall the closure is simplified to one requiring the solution of approximated transport equations for only the turbulent shear stress, the turbulent kinetic energy and the energy dissipation rate. Numerical solutions are presented for turbulent channel flow and sink flows at low Reynolds number as well as a case of a severely accelerated boundary layer in which the turbulent shear stress becomes negligible compared with the viscous stresses. Agreement with experiment is generally encouraging.

A Low-Reynolds Number Explicit Algebraic Stress Model

2006 ◽  
Vol 128 (6) ◽  
pp. 1364-1376 ◽  
Author(s):  
M. M. Rahman ◽  
T. Siikonen
Keyword(s):  
Reynolds Number ◽  
Low Reynolds Number ◽  
Stress Model ◽  
Algebraic Stress Model ◽  
Numerical Instabilities ◽  
Low Reynolds ◽  
Prandtl Numbers ◽  
Dissipation Equation ◽  
Good Agreement ◽  
Near Wall

A low-Reynolds number extension of the explicit algebraic stress model, developed by Gatski and Speziale (GS) is proposed. The turbulence anisotropy Πb and production to dissipation ratio P∕ϵ are modeled that recover the established equilibrium values for the homogeneous shear flows. The devised (Πb, P∕ϵ) combined with the model coefficients prevent the occurrence of nonphysical turbulence intensities in the context of a mild departure from equilibrium, and facilitate an avoidance of numerical instabilities, involved in the original GS model. A new near-wall damping function fμ in the eddy viscosity relation is introduced. To enhance dissipation in near-wall regions, the model constants Cϵ(1,2) are modified and an extra positive source term is included in the dissipation equation. A realizable time scale is incorporated to remove the wall singularity. The turbulent Prandtl numbers σ(k,ϵ) are modeled to provide substantial turbulent diffusion in near-wall regions. The model is validated against a few flow cases, yielding predictions in good agreement with the direct numerical simulation and experimental data.

Two-Layer Approach Combining Reynolds Stress and Low-Reynolds-Number k-e Models

AIAA Journal ◽  
10.2514/2.707 ◽  
1999 ◽  
Vol 37 (2) ◽  
pp. 283-287 ◽  
Author(s):  
W. D. Hsieh ◽  
K. C. Chang
Keyword(s):  
Reynolds Number ◽  
Reynolds Stress ◽  
Low Reynolds Number ◽  
Low Reynolds
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