Symmetry of turbulent boundary-layer flows: Investigation of different eddy viscosity models

2001 ◽  
Vol 151 (1-2) ◽  
pp. 1-14 ◽  
Author(s):  
A. A. Avramenko ◽  
S. G. Kobzar ◽  
I. V. Shevchuk ◽  
A. V. Kuznetsov ◽  
L. T. Iwanisov
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Eddy Viscosity ◽  
Boundary Layer Flows ◽  
Viscosity Models

High-Pass Filtered Eddy-Viscosity Models for Large-Eddy Simulations of Compressible Wall-Bounded Flows

2005 ◽  
Vol 127 (4) ◽  
pp. 666-673 ◽  
Author(s):  
Steffen Stolz
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Large Eddy Simulation ◽  
Eddy Viscosity ◽  
Correct Prediction ◽  
Smagorinsky Model ◽  
Eddy Simulation ◽  
Viscosity Models ◽  
Large Eddy ◽  
High Pass

In this contribution we consider large-eddy simulation (LES) using the high-pass filtered (HPF) Smagorinsky model of a spatially developing supersonic turbulent boundary layer at a Mach number of 2.5 and momentum-thickness Reynolds numbers at inflow of ∼4500. The HPF eddy-viscosity models employ high-pass filtered quantities instead of the full velocity field for the computation of the subgrid-scale (SGS) model terms. This approach has been proposed independently by Vreman (Vreman, A. W., 2003, Phys. Fluids, 15, pp. L61–L64) and Stolz et al. (Stolz, S., Schlatter, P., Meyer, D., and Kleiser, L., 2003, in Direct and Large Eddy Simulation V, Kluwer, Dordrecht, pp. 81–88). Different from classical eddy-viscosity models, such as the Smagorinsky model (Smagorinsky, J., 1963, Mon. Weath. Rev, 93, pp. 99–164) or the structure-function model (Métais, O. and Lesieur, M., 1992, J. Fluid Mech., 239, pp. 157–194) which are among the most often employed SGS models for LES, the HPF eddy-viscosity models do need neither van Driest wall damping functions for a correct prediction of the viscous sublayer of wall-bounded turbulent flows nor a dynamic determination of the coefficient. Furthermore, the HPF eddy-viscosity models are formulated locally and three-dimensionally in space. For compressible flows the model is supplemented by a HPF eddy-diffusivity ansatz for the SGS heat flux in the energy equation. Turbulent inflow conditions are generated by a rescaling and recycling technique in which the mean and fluctuating part of the turbulent boundary layer at some distance downstream of inflow is rescaled and reintroduced at the inflow position (Stolz, S. and Adams, N. A., 2003, Phys. Fluids, 15, pp. 2389–2412).

High-Pass Filtered Eddy-Viscosity Models for Large-Eddy Simulations of Compressible Wall-Bounded Flows

2004 ◽  
Author(s):  
Steffen Stolz
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Eddy Viscosity ◽  
Large Eddy Simulations ◽  
Scale Model ◽  
Subgrid Scale ◽  
Smagorinsky Model ◽  
Viscosity Models ◽  
Large Eddy ◽  
High Pass

Eddy-viscosity models such as the Smagorinsky model [1] are the most often employed subgrid-scale (SGS) models for large-eddy simulations (LES). However, for a correct prediction of the viscous sublayer of wall-bounded turbulent flows van-Driest wall damping functions or a dynamic determination of the constant [2] have to be employed. Alternatively, high-pass filtered (HPF) quantities can be used instead of the full velocity field for the computation of the subgrid-scale model terms. This approach has been independently proposed by Vreman [3] and Stolz et al. [4]. In this contribution we consider LES of a spatially developing supersonic turbulent boundary layer at a Mach number of 2.5 and momentum-thickness Reynolds numbers at inflow of approximately 4500, using the HPF Smagorinsky model. The model is supplemented by a HPF eddy-diffusivity ansatz for the SGS heat flux in the energy equation. Turbulent inflow conditions are generated by a rescaling and recycling technique proposed by [5] where the mean and fluctuating part of the turbulent boundary layer at some distance downstream of inflow is rescaled and reintroduced at inflow.

Numerical Study of Vortical Separation From a Three-Dimensional Hill Using Eddy-Viscosity Models

2015 ◽  
Author(s):  
Varun Chitta ◽  
Tausif Jamal ◽  
Keith Walters
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Eddy Viscosity ◽  
Three Dimensional ◽  
Flow Transition ◽  
Mean Flow ◽  
New Model ◽  
Streamline Curvature ◽  
Viscosity Models ◽  
Rans Models

Turbulent flow over an axisymmetric hill is highly three-dimensional (3D) due to the presence of both streamwise and spanwise pressure gradients. Complex vortical separations and reattachments of the turbulent boundary layer are observed on the lee side, accurate prediction of which presents a demanding task for linear eddy-viscosity models (EVMs) when compared to attached boundary layer flows. In this study, an axisymmetric hill is investigated using three Reynolds-averaged Navier-Stokes (RANS) models — fully turbulent model (SST k-ω), transition-sensitive model (k-kL-ω), and a new four-equation model (k-kL-ω-v2). The new model is designed to exhibit physically correct responses to flow transition, streamline curvature, and system rotation effects. The test case includes a hill mounted in a channel with hill height H = 2δ, where δ is the approach turbulent boundary layer thickness. The flow Reynolds number (Re) based on the hill height is ReH = 1.3 × 105. Computational fluid dynamics (CFD) simulation results obtained using the new model are compared with the other two RANS models and with experimental data. Improved mean flow statistics are obtained using the new model that match well with the experiments. The results from this study highlight the need for a model that is able to resolve both flow transition and streamline curvature effects over blunt/curved bodies with reasonable engineering accuracy and computational cost.

COMPUTATION OF TWO-DIMENSIONAL INCOMPRESSIBLE TURBULENT BOUNDARY LAYER FLOWS WITH EQUILIBRIUM AND NONEQUILIBRIUM TURBULENCE MODELS

1994 ◽  
Vol 05 (02) ◽  
pp. 207-210
Author(s):  
Daniel Wong ◽  
Salahuddin Ahmed
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Turbulence Models ◽  
Two Dimensional ◽  
Reynolds Stresses ◽  
Mean Flow ◽  
Boundary Layer Flows ◽  
Boundary Layer Equations ◽  
Viscosity Models ◽  
Incompressible Turbulent Boundary Layer

Two-dimensional incompressible turbulent boundary layer flows over a flat plate were predicted using turbulent boundary layer equations. Reynolds stresses were calculated using Cebeci-Smith, Baldwin-Lomax, and Johnson-King eddy viscosity models. Computational results of mean-flow properties based on Cebeci-Smith model and Baldwin-Lomax model are in excellent agreement with experimental data, and, those based on Johnson-King model are not as accurate as the other two models.

An Assessment of Three-Dimensional Turbulent Boundary Layer Prediction Methods

1973 ◽  
Vol 95 (3) ◽  
pp. 415-421 ◽  
Author(s):  
A. J. Wheeler ◽  
J. P. Johnston
Keyword(s):  
Boundary Layer ◽  
Eddy Viscosity ◽  
Three Dimensional ◽  
High Sensitivity ◽  
Boundary Layer Flows ◽  
Mean Velocity ◽  
Eddy Viscosity Model ◽  
Separating Flow ◽  
Dimensional Boundary ◽  
Stress Models

Predictions have been made for a variety of experimental three-dimensional boundary layer flows with a single finite difference method which was used with three different turbulent stress models: (i) an eddy viscosity model, (ii) the “Nash” model, and (iii) the “Bradshaw” model. For many purposes, even the simplest stress model (eddy viscosity) was adequate to predict the mean velocity field. On the other hand, the profile of shear stress direction was not correctly predicted in one case by any model tested. The high sensitivity of the predicted results to free stream pressure gradient in separating flow cases is demonstrated.

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