In this investigation, qualitative comparisons with experimentally obtained PIV data from a scale... more In this investigation, qualitative comparisons with experimentally obtained PIV data from a scale-model wind tunnel facility are made with numerical solutions obtained using CFD for the Japan Bulk Carrier (JBC) geometry. Distributions of relevant quantities such as local velocity, local vorticity and local turbulence quantities at specific locations in the near-stern region are compared in both straight-ahead and pure-drift configurations. For the numerical investigation, a new turbulence model, Generalized k-omega (GEKO), is employed. This model combines the approach of various other two-equation RANS based models and extends the range of application by providing the user with free parameters (based on near-wall influence, flow separation, mixing, and jet spreading) that can be adjusted for specific types of flow. The effect of varying the separation coefficient, C_SEP on the hull wake characteristics of the JBC is examined. Grid dependence studies for various types of unstructured...
FLOMANIA — A European Initiative on Flow Physics Modelling
The main targets for ANSYS in FLOMANIA are turbulence model improvements and the validation of es... more The main targets for ANSYS in FLOMANIA are turbulence model improvements and the validation of established turbulence models. These issues are: – Development of an improved DES model based on the SST turbulence model – Evaluation of the DES model for separated flows – Support the definition of common RSM formulation – Provide know-how on advanced wall treatments to consortium.
An overview of scale-resolving simulation (SRS) methods used in ANSYS Computational Fluid Dynamic... more An overview of scale-resolving simulation (SRS) methods used in ANSYS Computational Fluid Dynamics (CFD) software is provided. The main challenges, especially when computing boundary layers in large eddy simulation (LES) mode, will be discussed. The different strategies for handling wall-bound flows using combinations of RANS and LES models will be explained, along with some specific application examples. It will be demonstrated that the stress-blended eddy simulation (SBES) approach is optimal for applications with a mix of boundary layers and free shear flows due to its low cost and its ability to handle boundary layers in both RANS and wall-modeled LES (WMLES) modes.
Accurate numerical prediction of surface heat transfer in the presence of film cooling within aer... more Accurate numerical prediction of surface heat transfer in the presence of film cooling within aero-engine sub-components, such as blade effusion holes and combustor liners, has long been a goal of the aero-engine industry. It requires accurate simulation of the turbulent mixing and reaction processes between freestream and the cooling flow. In this study, the stress-blended eddy simulation (SBES) turbulence model is used together with the flamelet generated manifold (FGM) combustion model to calculate the surface heat flux upstream and downstream of an effusion cooling hole. The SBES model employs a blending function to automatically switch between Reynolds-averaged Navier–Stokes (RANS) and large eddy simulation (LES) based on the local flow features, and thus significantly reduces the computational cost compared to a full LES simulation. All simulations are run using ansys fluent®, a commercial finite-volume computational fluid dynamics (CFD) solver. The test case corresponds to an...
23rd Fluid Dynamics, Plasmadynamics, and Lasers Conference, 1993
Two new versions of the kw two-equation turbulence model will be presented. The new Baseline (BSL... more Two new versions of the kw two-equation turbulence model will be presented. The new Baseline (BSL) model is designed to give results similar to those of the original kw model of Wilcox. but without its strong dependency on arbitrary freestream values. The BSL model is identical to the Wilcox model in the inner SOC7£; of the boundary-layer but changes gradually to the standard kf. model (in a kw fonnulation) towards the boundary-layer edge. The new model is also virtually identical to the kf. model for free shear layers. The second version of the model is called Shear-Stress Transport (SSn model. It is a variation of the BSL model with the additional ability to account for the transport of the principal turbulent shear stress in adverse pressure gradient boundary-layers. The model is based on Bradshaw's assumption that the principal shear-stress is proportional to the turbulent kinetic energy, which is introduced into the definition of the eddy-viscosity. Both models are tested for a large number of different fiowfields. The results of the BSL model are similar to those of the original kw model, but without the undesirable free stream dependency. The predictions of the SST model are also independent of the freestrearn values but show better agreement with experimental data for adverse pressure gradient boundary-layer flows.
Proceedings of the Third International Conference on Engineering Computational Technology
ABSTRACT A challenge in engineering computational technology is the simulation of multiphysics ap... more ABSTRACT A challenge in engineering computational technology is the simulation of multiphysics applications where different physical phenomena are involved such as fluid-structure interactions. A simulation strategy is to solve each part with an existing software package and to couple both processes by a data interface between the software codes. The advantage of using existing software packages is that one can benefit from their advanced features. The finite volume fluid analysis code CFX-5 is extended by a data interface, which handles the communication communicates with the finite element structural analysis code MSC.Marc using the coupling library MpCCI, and in addition with a rigid body module. The implemented communication concept offers a flexible way for defining the coupling algorithm. Different test cases are run to demonstrate the features of the coupling concept, including an efficient data transfer, flexible and scalable coupling, and good parallel performance on multi-processor computers.
A numerical method will be presented to solve the three-dimensional Navier-Stokes equations in co... more A numerical method will be presented to solve the three-dimensional Navier-Stokes equations in combination with a full Reynolds-stress turbulence model. Computations will be shown for three complex flowfields. The results of the Reynolds-stress model will be compared with those predicted by two different versions of the k-co model. It will be shown that an improved version of the k-co model gives as accurate results as the Reynolds-stress model.
Lecture Notes in Applied and Computational Mechanics
In the last decade, the spectrum of methodologies for the modeling of unsteady flows has signific... more In the last decade, the spectrum of methodologies for the modeling of unsteady flows has significantly increased. Historically, the two choices were Unsteady Reynolds Averaged Navier-Stokes (URANS) and Large Eddy Simulation (LES) methods. Both have severe limitations with respect to their application to engineering flows. URANS, typically produces no turbulent spectral information, even in regions, where time and space resolution would be sufficient to do so, whereas LES requires very high grid counts for modeling of wall-bounded flows at moderate to high Reynolds numbers. CFD users therefore had little choice than to concentrate on steady state RANS solutions, even for applications, where it was clear that these models are not adequate. Detached Eddy Simulation (DES) as proposed by Spalart in 1997, lead to a shift in paradigm, as it combined the elements of RANS and LES in a way that allowed the simulation of unsteady detached flows with available computing power. More recent studies by Menter and Egorov, have however shown that the inability of classical URANS models to resolve turbulent structures is not an inherent shortcoming of the URANS approach, but only related to the way the scale equations have historically been derived. After re-visiting an exact scale equation that Rotta had developed in the 1950s, it became clear that an important term was omitted in all scale equations, which resulted in the inability of classical RANS models to resolve unsteady structures. Closer inspection of Rotta's equation shows that the second derivative of the velocity field should be included in the length scale equation. This so-called Scale-Adaptive Simulation (SAS) methodology behaves in many ways and for many applications similar to the DES formulation, but avoids some of the dangers of DES. On the other hand, it is not the goal of SAS to replace DES and it will be shown that both methods have their place in the spectrum of unsteady turbulence models. The paper will discuss the practical implications, but also the limitations of the SAS technology. Many results produced during the European research project DESIDER on external aerodynamic flow will be shown.
A new oil-fringe imaging skin friction (FISF) technique to measure skin friction on wind tunnel m... more A new oil-fringe imaging skin friction (FISF) technique to measure skin friction on wind tunnel models is presented. In the method used to demonstrate the technique, lines of oil are applied on surfaces that connect the intended sets of measurement points, and then a wind tunnel is run so that the oil thins and forms interference fringes that are spaced proportional to local skin friction. After a run the fringe spacings are imaged with a CCD-array digital camera and measured on a computer. Skin friction and transition measurements on a two-dimensional wing are presented and compared with computational predictions.
The present paper describes first efforts carried out to extend the range of Scale-Adaptive Simul... more The present paper describes first efforts carried out to extend the range of Scale-Adaptive Simulation (SAS) methods into the area of RANSstable flows. Instead of relying on inherent flow instabilities for generating resolved turbulence in unstable regimes, the current approach employs forcing terms for transferring modelled turbulence energy into resolved energy in pre-specified regions of the simulation domain.
The state of Scale-Resolving Simulation (SRS) techniques for turbulent flow predictions in CFD wi... more The state of Scale-Resolving Simulation (SRS) techniques for turbulent flow predictions in CFD will be reviewed. The emphasis will be on turbulence models which are already in use in industrial simulations. The appropriate application areas for each model group will be discussed.
Modi¦cations are proposed of two recently developed hybrid CFD (computational §uid dynamics) stra... more Modi¦cations are proposed of two recently developed hybrid CFD (computational §uid dynamics) strategies, Delayed Detached Eddy Simulation (DDES), and DDES with Improved wall-modeling capability (IDDES). The modi¦cations are aimed at ¦ne-tuning of these approaches to the kω SST (shear stress transport) background RANS (Reynolds-averaged NavierStokes) model. The ¦rst one includes recalibrated empirical constants in the shielding function of the Spalart Allmaras (SA) based DDES which are shown to be suboptimal (not providing a needed level of elimination of the Model Stress Depletion (MSD)) for the SST-based DDES model. For the SST-IDDES variant, in addition to that, a simpli¦cation of the original SA-based formulation is proposed, which does not cause any visible degradation of the model performance. Both modi¦cations are extensively tested on a range of attached and separated §ows (developed channel, backward-facing step, periodic hills, wall-mounted hump, and hydrofoil with trailing edge separation).
Engineering Turbulence Modelling and Experiments, 1996
A formalism will be presented that allows the transformation of two-equation eddy viscosity turbu... more A formalism will be presented that allows the transformation of two-equation eddy viscosity turbulence models into one-equation models. The transformation is based on an assumption that is widely accepted over a large range of boundary layer flows and that has been shown to actually improve predictions when incorporated into two-equation models of turbulence. Based on that assumption, a new one-equation turbulence model will be derived. The new model will be tested in great detail against a previously introduced one-equation model and against its parent twoequation model.
The ability of one-and two-equation turbulence models to predict unsteady separated flows over ai... more The ability of one-and two-equation turbulence models to predict unsteady separated flows over airfoils is evaluated. An implicit, factorized, upwindbiased numerical scheme is used for the integration of the compressible, Reynolds averaged Navier-Stokes
Recently the authors have proposed the Scale-Adaptive Simulations (SAS) model for the simulation ... more Recently the authors have proposed the Scale-Adaptive Simulations (SAS) model for the simulation of unsteady turbulent flows (1,2). The model is continuously developed within the EU project DESIDER. The formulation can operate in standard RANS mode, but has the capability of resolving the turbulent spectrum in unsteady flow regions. SAS models adapt the length- scale automatically to the resolved scales of the flow field. The distinguishing factor in the model is the use of the von Karman length-scale, LvK: The SAS two-equation model reads:
Being of importance for turbulent and thermal mixing and consequently for thermal striping and th... more Being of importance for turbulent and thermal mixing and consequently for thermal striping and thermal fatigue problems in nuclear power plants, the turbulent isothermal and thermal mixing phenomena have been investigated in two different testcase scenarios. First testcase scenario as proposed by ETHZ, Prasser et al. [18] comprises of turbulent mixing of two water streams of equal temperature in a T-junction of 50mm pipes in the horizontal plane and thereby excluding any buoyancy effects. The second testcase is based on the Vattenfall test facility in the Älvkarleby laboratory and has been proposed by Westin et al. [16], where water of 15K temperature difference mixes in a T-junction in vertical plane, provoking thermal striping phenomena. ANSYS CFX 11.0 with Reynolds averaging based (U)RANS turbulence models (SST, BSL RSM) as well as with scale-resolving SAS-SST turbulence model has been applied to both test cases. The CFD simulations have been carried out in accordance with Best Practice Guidelines as far as they were applicable. Results have been compared to wire-mesh sensor, LDV and thermocouple measurements. While the turbulent mixing in the ETHZ testcase could be reproduced in good quantitative agreement with data, the results of the LES-like simulations were not yet fully satisfying in terms of the obtained accuracy in comparison to the detailed measurement data, also the transient thermal striping phenomena and large-scale turbulence structure development was well reproduced in the simulations.
An investigation of different turbulence Scale-Resolving Simulation (SRS) modeling approaches for... more An investigation of different turbulence Scale-Resolving Simulation (SRS) modeling approaches for the flow in a T-junction has been conducted using the Scale-Adaptive Simulation (SAS), the Delayed Detached Eddy Simulation (DDES) and the Embedded Large Eddy Simulation (ELES) methods. The results show that all models are able to accurately predict the mean and RMS velocity profiles, when used in combination with a low dissipation advection scheme. However, when a slightly more dissipative scheme is used, the SAS model yields less accurate results, indicating that this flow does not produce a strong enough flow instability to allow the safe application of this model. The DDES and the ELES models show less sensitivity to the numerical setting compared to the SAS model. The main goal of the study is the accurate prediction of heat transfer on the walls in the mixing zone. In that respect, the ELES method produces the most consistent agreement with the experimental data.
In this investigation, qualitative comparisons with experimentally obtained PIV data from a scale... more In this investigation, qualitative comparisons with experimentally obtained PIV data from a scale-model wind tunnel facility are made with numerical solutions obtained using CFD for the Japan Bulk Carrier (JBC) geometry. Distributions of relevant quantities such as local velocity, local vorticity and local turbulence quantities at specific locations in the near-stern region are compared in both straight-ahead and pure-drift configurations. For the numerical investigation, a new turbulence model, Generalized k-omega (GEKO), is employed. This model combines the approach of various other two-equation RANS based models and extends the range of application by providing the user with free parameters (based on near-wall influence, flow separation, mixing, and jet spreading) that can be adjusted for specific types of flow. The effect of varying the separation coefficient, C_SEP on the hull wake characteristics of the JBC is examined. Grid dependence studies for various types of unstructured...
FLOMANIA — A European Initiative on Flow Physics Modelling
The main targets for ANSYS in FLOMANIA are turbulence model improvements and the validation of es... more The main targets for ANSYS in FLOMANIA are turbulence model improvements and the validation of established turbulence models. These issues are: – Development of an improved DES model based on the SST turbulence model – Evaluation of the DES model for separated flows – Support the definition of common RSM formulation – Provide know-how on advanced wall treatments to consortium.
An overview of scale-resolving simulation (SRS) methods used in ANSYS Computational Fluid Dynamic... more An overview of scale-resolving simulation (SRS) methods used in ANSYS Computational Fluid Dynamics (CFD) software is provided. The main challenges, especially when computing boundary layers in large eddy simulation (LES) mode, will be discussed. The different strategies for handling wall-bound flows using combinations of RANS and LES models will be explained, along with some specific application examples. It will be demonstrated that the stress-blended eddy simulation (SBES) approach is optimal for applications with a mix of boundary layers and free shear flows due to its low cost and its ability to handle boundary layers in both RANS and wall-modeled LES (WMLES) modes.
Accurate numerical prediction of surface heat transfer in the presence of film cooling within aer... more Accurate numerical prediction of surface heat transfer in the presence of film cooling within aero-engine sub-components, such as blade effusion holes and combustor liners, has long been a goal of the aero-engine industry. It requires accurate simulation of the turbulent mixing and reaction processes between freestream and the cooling flow. In this study, the stress-blended eddy simulation (SBES) turbulence model is used together with the flamelet generated manifold (FGM) combustion model to calculate the surface heat flux upstream and downstream of an effusion cooling hole. The SBES model employs a blending function to automatically switch between Reynolds-averaged Navier–Stokes (RANS) and large eddy simulation (LES) based on the local flow features, and thus significantly reduces the computational cost compared to a full LES simulation. All simulations are run using ansys fluent®, a commercial finite-volume computational fluid dynamics (CFD) solver. The test case corresponds to an...
23rd Fluid Dynamics, Plasmadynamics, and Lasers Conference, 1993
Two new versions of the kw two-equation turbulence model will be presented. The new Baseline (BSL... more Two new versions of the kw two-equation turbulence model will be presented. The new Baseline (BSL) model is designed to give results similar to those of the original kw model of Wilcox. but without its strong dependency on arbitrary freestream values. The BSL model is identical to the Wilcox model in the inner SOC7£; of the boundary-layer but changes gradually to the standard kf. model (in a kw fonnulation) towards the boundary-layer edge. The new model is also virtually identical to the kf. model for free shear layers. The second version of the model is called Shear-Stress Transport (SSn model. It is a variation of the BSL model with the additional ability to account for the transport of the principal turbulent shear stress in adverse pressure gradient boundary-layers. The model is based on Bradshaw's assumption that the principal shear-stress is proportional to the turbulent kinetic energy, which is introduced into the definition of the eddy-viscosity. Both models are tested for a large number of different fiowfields. The results of the BSL model are similar to those of the original kw model, but without the undesirable free stream dependency. The predictions of the SST model are also independent of the freestrearn values but show better agreement with experimental data for adverse pressure gradient boundary-layer flows.
Proceedings of the Third International Conference on Engineering Computational Technology
ABSTRACT A challenge in engineering computational technology is the simulation of multiphysics ap... more ABSTRACT A challenge in engineering computational technology is the simulation of multiphysics applications where different physical phenomena are involved such as fluid-structure interactions. A simulation strategy is to solve each part with an existing software package and to couple both processes by a data interface between the software codes. The advantage of using existing software packages is that one can benefit from their advanced features. The finite volume fluid analysis code CFX-5 is extended by a data interface, which handles the communication communicates with the finite element structural analysis code MSC.Marc using the coupling library MpCCI, and in addition with a rigid body module. The implemented communication concept offers a flexible way for defining the coupling algorithm. Different test cases are run to demonstrate the features of the coupling concept, including an efficient data transfer, flexible and scalable coupling, and good parallel performance on multi-processor computers.
A numerical method will be presented to solve the three-dimensional Navier-Stokes equations in co... more A numerical method will be presented to solve the three-dimensional Navier-Stokes equations in combination with a full Reynolds-stress turbulence model. Computations will be shown for three complex flowfields. The results of the Reynolds-stress model will be compared with those predicted by two different versions of the k-co model. It will be shown that an improved version of the k-co model gives as accurate results as the Reynolds-stress model.
Lecture Notes in Applied and Computational Mechanics
In the last decade, the spectrum of methodologies for the modeling of unsteady flows has signific... more In the last decade, the spectrum of methodologies for the modeling of unsteady flows has significantly increased. Historically, the two choices were Unsteady Reynolds Averaged Navier-Stokes (URANS) and Large Eddy Simulation (LES) methods. Both have severe limitations with respect to their application to engineering flows. URANS, typically produces no turbulent spectral information, even in regions, where time and space resolution would be sufficient to do so, whereas LES requires very high grid counts for modeling of wall-bounded flows at moderate to high Reynolds numbers. CFD users therefore had little choice than to concentrate on steady state RANS solutions, even for applications, where it was clear that these models are not adequate. Detached Eddy Simulation (DES) as proposed by Spalart in 1997, lead to a shift in paradigm, as it combined the elements of RANS and LES in a way that allowed the simulation of unsteady detached flows with available computing power. More recent studies by Menter and Egorov, have however shown that the inability of classical URANS models to resolve turbulent structures is not an inherent shortcoming of the URANS approach, but only related to the way the scale equations have historically been derived. After re-visiting an exact scale equation that Rotta had developed in the 1950s, it became clear that an important term was omitted in all scale equations, which resulted in the inability of classical RANS models to resolve unsteady structures. Closer inspection of Rotta's equation shows that the second derivative of the velocity field should be included in the length scale equation. This so-called Scale-Adaptive Simulation (SAS) methodology behaves in many ways and for many applications similar to the DES formulation, but avoids some of the dangers of DES. On the other hand, it is not the goal of SAS to replace DES and it will be shown that both methods have their place in the spectrum of unsteady turbulence models. The paper will discuss the practical implications, but also the limitations of the SAS technology. Many results produced during the European research project DESIDER on external aerodynamic flow will be shown.
A new oil-fringe imaging skin friction (FISF) technique to measure skin friction on wind tunnel m... more A new oil-fringe imaging skin friction (FISF) technique to measure skin friction on wind tunnel models is presented. In the method used to demonstrate the technique, lines of oil are applied on surfaces that connect the intended sets of measurement points, and then a wind tunnel is run so that the oil thins and forms interference fringes that are spaced proportional to local skin friction. After a run the fringe spacings are imaged with a CCD-array digital camera and measured on a computer. Skin friction and transition measurements on a two-dimensional wing are presented and compared with computational predictions.
The present paper describes first efforts carried out to extend the range of Scale-Adaptive Simul... more The present paper describes first efforts carried out to extend the range of Scale-Adaptive Simulation (SAS) methods into the area of RANSstable flows. Instead of relying on inherent flow instabilities for generating resolved turbulence in unstable regimes, the current approach employs forcing terms for transferring modelled turbulence energy into resolved energy in pre-specified regions of the simulation domain.
The state of Scale-Resolving Simulation (SRS) techniques for turbulent flow predictions in CFD wi... more The state of Scale-Resolving Simulation (SRS) techniques for turbulent flow predictions in CFD will be reviewed. The emphasis will be on turbulence models which are already in use in industrial simulations. The appropriate application areas for each model group will be discussed.
Modi¦cations are proposed of two recently developed hybrid CFD (computational §uid dynamics) stra... more Modi¦cations are proposed of two recently developed hybrid CFD (computational §uid dynamics) strategies, Delayed Detached Eddy Simulation (DDES), and DDES with Improved wall-modeling capability (IDDES). The modi¦cations are aimed at ¦ne-tuning of these approaches to the kω SST (shear stress transport) background RANS (Reynolds-averaged NavierStokes) model. The ¦rst one includes recalibrated empirical constants in the shielding function of the Spalart Allmaras (SA) based DDES which are shown to be suboptimal (not providing a needed level of elimination of the Model Stress Depletion (MSD)) for the SST-based DDES model. For the SST-IDDES variant, in addition to that, a simpli¦cation of the original SA-based formulation is proposed, which does not cause any visible degradation of the model performance. Both modi¦cations are extensively tested on a range of attached and separated §ows (developed channel, backward-facing step, periodic hills, wall-mounted hump, and hydrofoil with trailing edge separation).
Engineering Turbulence Modelling and Experiments, 1996
A formalism will be presented that allows the transformation of two-equation eddy viscosity turbu... more A formalism will be presented that allows the transformation of two-equation eddy viscosity turbulence models into one-equation models. The transformation is based on an assumption that is widely accepted over a large range of boundary layer flows and that has been shown to actually improve predictions when incorporated into two-equation models of turbulence. Based on that assumption, a new one-equation turbulence model will be derived. The new model will be tested in great detail against a previously introduced one-equation model and against its parent twoequation model.
The ability of one-and two-equation turbulence models to predict unsteady separated flows over ai... more The ability of one-and two-equation turbulence models to predict unsteady separated flows over airfoils is evaluated. An implicit, factorized, upwindbiased numerical scheme is used for the integration of the compressible, Reynolds averaged Navier-Stokes
Recently the authors have proposed the Scale-Adaptive Simulations (SAS) model for the simulation ... more Recently the authors have proposed the Scale-Adaptive Simulations (SAS) model for the simulation of unsteady turbulent flows (1,2). The model is continuously developed within the EU project DESIDER. The formulation can operate in standard RANS mode, but has the capability of resolving the turbulent spectrum in unsteady flow regions. SAS models adapt the length- scale automatically to the resolved scales of the flow field. The distinguishing factor in the model is the use of the von Karman length-scale, LvK: The SAS two-equation model reads:
Being of importance for turbulent and thermal mixing and consequently for thermal striping and th... more Being of importance for turbulent and thermal mixing and consequently for thermal striping and thermal fatigue problems in nuclear power plants, the turbulent isothermal and thermal mixing phenomena have been investigated in two different testcase scenarios. First testcase scenario as proposed by ETHZ, Prasser et al. [18] comprises of turbulent mixing of two water streams of equal temperature in a T-junction of 50mm pipes in the horizontal plane and thereby excluding any buoyancy effects. The second testcase is based on the Vattenfall test facility in the Älvkarleby laboratory and has been proposed by Westin et al. [16], where water of 15K temperature difference mixes in a T-junction in vertical plane, provoking thermal striping phenomena. ANSYS CFX 11.0 with Reynolds averaging based (U)RANS turbulence models (SST, BSL RSM) as well as with scale-resolving SAS-SST turbulence model has been applied to both test cases. The CFD simulations have been carried out in accordance with Best Practice Guidelines as far as they were applicable. Results have been compared to wire-mesh sensor, LDV and thermocouple measurements. While the turbulent mixing in the ETHZ testcase could be reproduced in good quantitative agreement with data, the results of the LES-like simulations were not yet fully satisfying in terms of the obtained accuracy in comparison to the detailed measurement data, also the transient thermal striping phenomena and large-scale turbulence structure development was well reproduced in the simulations.
An investigation of different turbulence Scale-Resolving Simulation (SRS) modeling approaches for... more An investigation of different turbulence Scale-Resolving Simulation (SRS) modeling approaches for the flow in a T-junction has been conducted using the Scale-Adaptive Simulation (SAS), the Delayed Detached Eddy Simulation (DDES) and the Embedded Large Eddy Simulation (ELES) methods. The results show that all models are able to accurately predict the mean and RMS velocity profiles, when used in combination with a low dissipation advection scheme. However, when a slightly more dissipative scheme is used, the SAS model yields less accurate results, indicating that this flow does not produce a strong enough flow instability to allow the safe application of this model. The DDES and the ELES models show less sensitivity to the numerical setting compared to the SAS model. The main goal of the study is the accurate prediction of heat transfer on the walls in the mixing zone. In that respect, the ELES method produces the most consistent agreement with the experimental data.
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Papers by Florian Menter