Wavelet-based adaptive unsteady Reynolds-averaged Navier-Stokes computations of wall-bounded internal and external compressible turbulent flows

The approach of Reynolds-averaged Navier–Stokes equations (RANS) for the modeling of turbulent flows is reviewed. The subject is mainly considered in the limit of incompressible flows with constant properties. After the introduction of the concept of Reynolds decomposition and averaging, different classes of RANS turbulence models are presented, and, in particular, zero-equation models, one-equation models (besides a half-equation model), two-equation models (with reference to the tensor representation used for a model, both linear and nonlinear models are considered), stress-equation models (with reference to the pressure-strain correlation, both linear and nonlinear models are considered) and algebraic-stress models. For each of the abovementioned class of models, the most widely-used modeling techniques and closures are reported. The unsteady RANS approach is also discussed and a section is devoted to hybrid RANS/large methods.

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Numerical Simulation of Non-Stationary Turbulent Flows Using Double Exponential Dynamic Time Filtering Technique

Volume 3: Computational Fluid Dynamics; Micro and Nano Fluid Dynamics ◽

10.1115/fedsm2020-20295 ◽

2020 ◽

Author(s):

Tausif Jamal ◽

Shanti Bhushan ◽

D. Keith Walters

Keyword(s):

Numerical Simulation ◽

Turbulent Flows ◽

Model Performance ◽

Navier Stokes ◽

Time Averaging ◽

Suitable Alternative ◽

Double Exponential ◽

Reynolds Averaged Navier Stokes ◽

Dynamic Hybrid ◽

Dynamic Time

Abstract Temporally varying turbulent flows are of considerable interest in complex engineering problems such as combustion, hydrodynamics, and hemodynamics. These types of flows are often associated with complex flow physics such as varying mean pressure gradients, interactions of different scales of motion, and complex boundary layer separations. Hybrid Reynolds-averaged Navier-Stokes (RANS)/Large-Eddy Simulation (LES) methods have recently shown promise for accurate and computationally efficient simulation of these flows. One such method is the dyanamic hybrid RANS-LES (DHRL) model which has been demonstrated for numerous statistically stationary turbulent flows. More recently, it has been shown that Exponential Time-Averaging (ETA) and Dynamic Time Filtering (DTF) methods for obtaining resolved flow statistics have significantly improved the predictive capabilities of the Dynamic Hybrid RANS-LES (DHRL) model performance for a non-stationary turbulent flows with periodically time-varying statistics. However, for non-periodic temporally evolving flows with monotonically varying statistics, a more suitable alternative is desired. In this study, the performance of the Dynamic Hybrid RANS-LES (DHRL) model with a double exponential dynamic time filtering (DDTF) methodology is evaluated against a Reynolds-Averaged Navier-Stokes (RANS) model, a conventional Hybrid RANS-LES (HRL) model, implicit LES, and the DHRL model with DTF for a pulsating channel and a temporally-varying turbulent mixing layer. Model performance is evaluated based on comparisons to existing experimental and Direct Numerical Simulation (DNS) results. A comprehensive analysis of the results highlights key similarities and differences between the models and indicates that the use of a double exponential DTF technique improves the accuracy of the baseline DHRL model. It is concluded that the DDTF is a useful alternative to simulate unsteady non-periodic temporally evolving turbulent flows.

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A modified blending function for zonal hybrid Reynolds-averaged Navier—Stokes/large-eddy simulation methodology

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1243/09544100jaero575 ◽

2009 ◽

Vol 223 (8) ◽

pp. 1067-1081 ◽

Cited By ~ 2

Author(s):

M B Sun ◽

J H Liang ◽

Z G Wang

Keyword(s):

Boundary Layer ◽

Supersonic Flow ◽

Large Eddy Simulation ◽

Turbulent Flows ◽

Navier Stokes ◽

Empirical Constant ◽

Eddy Simulation ◽

Large Eddy ◽

Reynolds Averaged Navier Stokes ◽

Blending Function

A modified blending function for zonal hybrid Reynolds averaged Navier—Stokes/large eddy simulation (RANS/LES) methodology was developed using an empirical analogy from Menter k—ω shear stress transport (SST) turbulent model (Menter, 1994) to predict complex turbulent flows. Tests of slot jet in supersonic flow and supersonic flow over compression—expansion ramp was conducted and prediction of separations was well improved when certain model constant was forced on the traditional blending function (Baurle et al., 2003). Analysis based on calculations of flat plate boundary layer demonstrated that an efficient empirical constant could be used in blending function and boundary layer could be well calculated without heavy contamination of RANS on wake region. Validation of the modified zonal hybrid RANS/LES approach for slot jet in supersonic flow, supersonic flow over compression—expansion ramp, supersonic flow over backward facing step, and supersonic cavity flow was conducted. The simulated results showed that the modified blending function performs well on complex turbulent flows. Deficiencies of traditional hybrid zonal RANS/LES method in over-prediction of separations associated with adverse pressure gradient flows were favourably improved.

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Analytical insights into the partially integrated transport modeling method for hybrid Reynolds averaged Navier-Stokes equations-large eddy simulations of turbulent flows

Physics of Fluids ◽

10.1063/1.4745003 ◽

2012 ◽

Vol 24 (8) ◽

pp. 085106 ◽

Cited By ~ 8

Author(s):

Bruno Chaouat ◽

Roland Schiestel

Keyword(s):

Turbulent Flows ◽

Stokes Equations ◽

Modeling Method ◽

Large Eddy Simulations ◽

Transport Modeling ◽

Navier Stokes ◽

Navier Stokes Equations ◽

Large Eddy ◽

Reynolds Averaged Navier Stokes

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Study of turbulent flow past a square cylinder using partially-averaged Navier–Stokes method in OpenFOAM

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406220910176 ◽

2020 ◽

Vol 234 (14) ◽

pp. 2821-2832 ◽

Cited By ~ 1

Author(s):

Arnab Chakraborty ◽

HV Warrior

Keyword(s):

Numerical Simulation ◽

Direct Numerical Simulation ◽

Turbulent Flow ◽

Turbulent Flows ◽

Normal Direction ◽

Navier Stokes ◽

Square Cylinder ◽

Mean Velocity ◽

Wide Range ◽

Reynolds Averaged Navier Stokes

The present paper reports numerical simulation of turbulent flow over a square cylinder using a novel scale resolving computational fluid dynamics technique named Partially-Averaged Navier–Stokes (PANS), which bridges Reynolds-Averaged Navier–Stokes (RANS) with Direct Numerical Simulation (DNS) in a seamless manner. All stream-wise and wall normal mean velocity components, turbulent stresses behavior have been computed along the flow (streamwise) as well as in transverse (wall normal) direction. The measurement locations are chosen based on the previous studies so that results could be compared. However, the Reynolds number ( Re) of the flow is maintained at 21,400 and K– ω turbulence model is considered for the present case. All the computations are performed in OpenFOAM framework using a finite volume solver. Additionally, turbulent kinetic energy variations are presented over a wide range of measurement planes in order to explain the energy transfer process in highly unsteady turbulent flow field. The fluctuating root mean square velocities in the streamwise as well as in the wall normal direction have been discussed in the present work. It has been found that Partially-Averaged Navier–Stokes (PANS) model is capable of capturing the properties of highly unsteady turbulent flows and gives better results than Reynolds-Averaged Navier–Stokes (RANS). The results obtained using Partially-Averaged Navier–Stokes (PANS) are quite comparable with Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS) data available in literature. The partially-averaged Navier–Stokes results are compared with our simulated Reynolds-Averaged Navier–Stokes (RANS) results, available experimental as well as numerical results in literature and it is found to be good in agreement.

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