Assessment of Eddy-Viscosity Turbulence Models on Flow in a Wheelhouse

Wind Tunnel Experiments ◽

Time Step ◽

Turbulent Eddies ◽

Eddy Simulation ◽

Abstract Six different turbulence models were used to simulate the flow within the wheelhouse of a simplified body. The performance of each model was evaluated by comparing the results to data collected from wind tunnel experiments. The performance of large eddy simulation (LES) and detached eddy simulation (DES) is largely dependent on the time step and grid size to accurately resolve turbulent eddies. The standard k–ω and k–ω SST models deviated the most from the experimental data. The standard k–ε model was found to produce the most consistent results which matched experimental data for the simplified body and wheel.

Towards Large-Eddy Simulation of Turbulent Flow in a Centrifugal Impeller

Volume 7: Turbomachinery, Parts A, B, and C ◽

10.1115/gt2011-45804 ◽

2011 ◽

Cited By ~ 1

Author(s):

Gorazd Medic ◽

Jinzhang Feng ◽

Liwei Chen ◽

Om Sharma

Keyword(s):

Large Eddy Simulation ◽

Turbulent Flow ◽

Eddy Viscosity ◽

Turbulence Models ◽

Scale Model ◽

Navier Stokes ◽

Centrifugal Impeller ◽

Eddy Simulation ◽

Large-eddy simulation (LES) using wall-adapting local eddy-viscosity (WALE) subgrid scale model has been applied towards elucidating the complex turbulent flow physics in a centrifugal impeller. Several canonical cases of increased complexity were analyzed to better understand the advantages and challenges of applying the LES framework to the aforementioned target problem. These include turbulent flow in a rotating channel, a straight and a curved duct. Results obtained with LES are compared in detail with two-equation eddy-viscosity Reynolds Averaged Navier-Stokes (RANS) turbulence models widely used in industry, as well as, for some of the canonical cases, with hybrid RANS/LES approaches such as the detached eddy simulation (DES) and scale-adaptive simulation (SAS). Finally, LES has been applied to turbulent flow in NASA CC3 centrifugal impeller with grids of increased resolution (up to 100 million computational cells per passage).

Evaluation of Turbulence Models Using Direct Numerical and Large-Eddy Simulation Data

Journal of Fluids Engineering ◽

10.1115/1.4003425 ◽

2011 ◽

Vol 133 (2) ◽

Cited By ~ 24

Author(s):

Hassan Raiesi ◽

Ugo Piomelli ◽

Andrew Pollard

Keyword(s):

Boundary Layer ◽

Large Eddy Simulation ◽

Eddy Viscosity ◽

Predictive Accuracy ◽

Turbulence Models ◽

Special Treatment ◽

Two Dimensional ◽

Square Duct ◽

Eddy Simulation ◽

The performance of some commonly used eddy-viscosity turbulence models has been evaluated using direct numerical simulation (DNS) and large-eddy simulation (LES) data. Two configurations have been tested, a two-dimensional boundary layer undergoing pressure-driven separation, and a square duct. The DNS and LES were used to assess the k−ε, ζ−f, k−ω, and Spalart–Allmaras models. For the two-dimensional separated boundary layer, anisotropic effects are not significant and the eddy-viscosity assumption works well. However, the near-wall treatment used in k−ε models was found to have a critical effect on the predictive accuracy of the model (and, in particular, of separation and reattachment points). None of the wall treatments tested resulted in accurate prediction of the flow field. Better results were obtained with models that do not require special treatment in the inner layer (ζ−f, k−ω, and Spalart–Allmaras models). For the square duct calculation, only a nonlinear constitutive relation was found to be able to capture the secondary flow, giving results in agreement with the data. Linear models had significant error.

Prediction of flow and dispersion in cross–ventilated buildings

E3S Web of Conferences ◽

10.1051/e3sconf/201912805002 ◽

2019 ◽

Vol 128 ◽

pp. 05002

Author(s):

Ali Cemal Benim ◽

Michael Diederich ◽

Ali Nahavandi

Keyword(s):

Computational Analysis ◽

Turbulence Models ◽

Reynolds Stress Model ◽

Turbulence Structure ◽

Mean Velocity ◽

Eddy Simulation ◽

Large Eddy ◽

The Mean ◽

Grid Independence

The present paper presents a detailed computational analysis of flow and dispersion in a generic isolated single–zone buildings. First, a grid generation strategy is discussed, that is inspired by a previous computational analysis and a grid independence study. Different turbulence models are appliedincluding two-equation turbulence models, the differential Reynolds Stress Model, Detached Eddy Simulation and Zonal Large Eddy Simulation. The mean velocity and concentration fields are calculated and compared with the measurements. A satisfactory agreement with the experiments is not observed by any of the modelling approaches, indicating the highly demanding flow and turbulence structure of the problem.

A Large Eddy Simulation of the Bubbly Flow in Vertical Tube

Volume 3: Thermal-Hydraulics; Turbines, Generators, and Auxiliaries ◽

10.1115/icone20-power2012-54362 ◽

2012 ◽

Author(s):

Peng Zhang ◽

Xu Hong

Keyword(s):

Large Eddy Simulation ◽

Eddy Viscosity ◽

Bubbly Flow ◽

Turbulence Models ◽

Vertical Tube ◽

Simulation Approach ◽

Bubble Distribution ◽

Eddy Simulation ◽

Large Eddy ◽

Two Fluid

This paper simulates the dispersed bubbly flow in a vertical tube with two different turbulence models based on Eulerian two-fluid frameworks. Both the RANS (Reynolds Averaged N-S equation) approach and LES (Large Eddy Simulation) approach can get results agreed with experiment well. The “wall peak” bubble distribution is captured. Compare with RANS with SST (Shear Stress Transport) turbulence model, the LES with WALE (Wall-Adapted Local Eddy-viscosity) sub-grid model can give transient and detail information of the flow field, and it shows better agreement.

Investigation of Flow Over an Airfoil Using a Hybrid Detached Eddy Simulation–Algebraic Stress Turbulence Model

Journal of Energy Resources Technology ◽

10.1115/1.4036050 ◽

2017 ◽

Vol 139 (5) ◽

Cited By ~ 3

Author(s):

Saman Beyhaghi ◽

Ryoichi S. Amano

Keyword(s):

Pressure Coefficient ◽

Turbulence Models ◽

Published Data ◽

Airfoil Surface ◽

Eddy Simulation ◽

Large Eddy ◽

Wall Flow ◽

Turbulent Air Flow ◽

Near Wall

Turbulent air flow over an NACA 4412 airfoil is investigated computationally. To overcome the near-wall inaccuracies of higher order turbulence models such as large Eddy simulation (LES) and detached Eddy simulation (DES), it is proposed to couple DES with algebraic stress model (ASM). Angles of attack (AoA) of 0 and 14 deg are studied for an airfoil subjected to flow with Re = 1.6 × 106. Distribution of the pressure coefficient at airfoil surface and the chordwise velocity component at four locations near the trailing edge are determined. Results of the baseline DES and hybrid DES–ASM models are compared against published data. It is demonstrated that the proposed hybrid model can slightly improve the flow predictions made by the DES model. Findings of this research can be used for the improvement of the near-wall flow predictions for wind turbine applications.

On the Investigation of Flow around the Square Cylinder Based on Different LES Models

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.594-597.2676 ◽

2012 ◽

Vol 594-597 ◽

pp. 2676-2679

Author(s):

Zhe Liu

Keyword(s):

Flow Characteristics ◽

Turbulence Models ◽

Navier Stokes ◽

Square Cylinder ◽

Rans Model ◽

Eddy Simulation ◽

Large Eddy ◽

Reynolds Averaged Navier Stokes ◽

Les Model

Although the conventional Reynolds-averaged Navier–Stokes (RANS) model has been widely applied in the industrial and engineering field, it is worthwhile to study whether these models are suitable to investigate the flow filed varying with the time. With the development of turbulence models, the unsteady Reynolds-averaged Navier–Stokes (URANS) model, detached eddy simulation (DES) and large eddy simulation (LES) compensate the disadvantage of RANS model. This paper mainly presents the theory of standard LES model, LES dynamic model and wall-adapting local eddy-viscosity (WALE) LES model. And the square cylinder is selected as the research target to study the flow characteristics around it at Reynolds number 13,000. The influence of different LES models on the flow field around the square cylinder is compared.

Some Observations on the Computational Sensitivity of Rotating Cavity Flows

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4049824 ◽

2021 ◽

Vol 143 (4) ◽

Author(s):

Tom Hickling ◽

Li He

Keyword(s):

Heat Transfer ◽

Eddy Viscosity ◽

Systematic Investigation ◽

Navier Stokes ◽

Cavity Flows ◽

Bulk Fluid ◽

Eddy Simulation ◽

Rotating Cavity ◽

Abstract Across the open literature, there is no clear consensus on what the most suitable modeling fidelity is for rotating cavity flows. Although it is a widely held opinion that unsteady Reynolds-averaged-Navier–Stokes (URANS) approaches are unsuitable, many authors have succeeded in getting reasonable heat transfer results with them. There is also a lack of research into the validity of hybrid URANS/large eddy simulation (LES) type approaches such as detached eddy simulation (DES). This paper addresses these research challenges with a systematic investigation of a rotating cavity with axial throughflow at Grashof numbers of 3.03×109 and 3.03×1011. The disk near-wall layers remained laminar at both conditions, meaning that a turbulence model should not be active in these regions. The disk heat transfer was observed to affect the near-disk aerodynamics, which in turn affect the disk heat transfer: this feedback loop implies that conjugate heat transfer computations of rotating cavities may be worth investigating. On the shroud, additional eddy viscosity in URANS and DES was found to interfere with the formation of heat transfer enhancing streaks, whilst these were always captured by LES. DES exhibited a concerning behavior at the higher Grashof number. Locally generated eddy viscosity from the shroud was injected into the bulk fluid by the radial inflow. This contaminated the entire cavity with nonphysical modeled turbulence. As the radial inflow is a characteristic feature of rotating cavity flows, these results show that caution is necessary when applying hybrid URANS/LES approaches to this type of flow.

Adaptive Detached-Eddy Simulation of Three-Dimensional Diffusers

Journal of Fluids Engineering ◽

10.1115/1.4034004 ◽

2016 ◽

Vol 138 (10) ◽

Cited By ~ 1

Author(s):

Paul Durbin ◽

Zifei Yin ◽

Elbert Jeyapaul

Keyword(s):

Pressure Coefficient ◽

Three Dimensional ◽

Side Wall ◽

Turbulence Models ◽

Adaptive Method ◽

Mean Velocity ◽

Eddy Simulation ◽

Large Eddy ◽

Default Data

An adaptive method for detached-eddy simulation (DES) is tested by simulations of flow in a family of three-dimensional (3D) diffusers. The adaptive method either adjusts the model constant or defaults to a bound if the grid is too coarse. On the present grids, the adaptive method adjusts the model constant over most of the flow, without resorting to the default. Data for the diffuser family were created by wall-resolved, large-eddy simulation (LES), using the dynamic Smagorinsky model, for the purpose of testing turbulence models. The family is a parameterized set of geometries that allows one to test whether the pattern of separation is moving correctly from the top to the side wall as the parameter increases. The adaptive DES model is quite accurate in this regard. It is found to predict the mean velocity accurately, but the pressure coefficient is underpredicted. The latter is due to the onset of separation being slightly earlier in the DES than in the LES.

Effect of Local Grid Refinement on Performance of Scale-Resolving Models for Simulation of Complex External Flows

Aerospace ◽

10.3390/aerospace6080086 ◽

2019 ◽

Vol 6 (8) ◽

pp. 86 ◽

Cited By ~ 1

Author(s):

Amne ElCheikh ◽

Michel ElKhoury

Keyword(s):

Computational Cost ◽

Flow Characteristics ◽

Turbulence Models ◽

Pollutant Dispersion ◽

Uniform Grid ◽

Grid Refinement ◽

Eddy Simulation ◽

Uniform Grids ◽

Numerical simulations are crucial for fast and accurate estimations of the flow characteristics in many engineering applications such as atmospheric boundary layers around buildings, external aerodynamics around vehicles, and pollutant dispersion. In the simulation of flow over urban-like obstacles, it is crucial to accurately resolve the flow characteristics with reasonable computational cost. Therefore, Large Eddy Simulations on non-uniform grids are usually employed. However, an undesirable accumulation of energy at grid-refinement interfaces was observed in previous studies using non-uniform grids. This phenomenon induced oscillations in the spanwise velocity component, mainly on fine-to-coarse grid interfaces. In this study, the two challenging test cases of flow over urban-like cubes and flow over a 3-D circular cylinder were simulated using three different scale-resolving turbulence models. Simulations were performed on uniform coarse and fine grids on one hand, and a non-uniform grid on the other, to assess the effect of mesh density and mesh interfaces on the models’ performance. Overall, the proposed One-Equation Scale-Adaptive Simulation (One-Equation SAS) showed the least deviation from the experimental results in both tested cases and on all grid sizes and types when compared to the Shear Stress Transport-Improved Delayed Detached Eddy Simulation (IDDES) and the Algebraic Wall-Modeled Large Eddy Simulation (WMLES).

Turbulence Models for Simulation of the Flow in a Rotor-Stator Cavity

EPJ Web of Conferences ◽

10.1051/epjconf/201921302104 ◽

2019 ◽

Vol 213 ◽

pp. 02104

Author(s):

Lucie Zemanová ◽

Pavel Rudolf

Keyword(s):

Turbulence Models ◽

Reynolds Stress Model ◽

Operating Conditions ◽

Narrow Gap ◽

Axial Thrust ◽

Eddy Simulation ◽

Adaptive Simulation ◽

Modelling of the flow in the cavities between rotor and stator in turbomachines (e.g. pumps or turbines) is a task of great interest. Correctly evaluated pressure and velocity fields enable calculation of the disk losses and therefore assessment of efficiency. It is also crucial for determination of axial thrust and thus design of the bearings. The study demonstrates abilities of various turbulence models to describe the flow in a narrow gap between rotating and stationary disks. Numerical simulations were performed in order to find out the ability of particular models to capture unstable structures appearing during specific operating conditions as well as to calculate the velocity profiles precisely. Large Eddy Simulation (LES), Scale Adaptive Simulation (SAS), Detached Eddy Simulation (DES), Reynolds stress model (RSM) and SST k – ω model were used. Obtained results were also compared with experimental measurement published by Viazzo et al. [1]