A Correlation-Based Transition Model Using Local Variables—Part I: Model Formulation
01 Jan 2004-Journal of Turbomachinery-transactions of The Asme (American Society of Mechanical Engineers)-Vol. 128, Iss: 3, pp 413-422
TL;DR: Langtry et al. as discussed by the authors developed a new correlation-based transition model based strictly on local variables, which is compatible with modern computational fluid dynamics (CFD) approaches, such as unstructured grids and massive parallel execution.
Abstract: A new correlation-based transition model has been developed, which is based strictly on local variables. As a result, the transition model is compatible with modern computational fluid dynamics (CFD) approaches, such as unstructured grids and massive parallel execution. The model is based on two transport equations, one for intermittency and one for the transition onset criteria in terms of momentum thickness Reynolds number. The proposed transport equations do not attempt to model the physics of the transition process (unlike, e.g., turbulence models) but form a framework for the implementation of correlation-based models into general-purpose CFD methods. Part I (this part) of this paper gives a detailed description of the mathematical formulation of the model and some of the basic test cases used for model validation, including a two-dimensional turbine blade. Part II (Langtry, R. B., Menter, F. R., Likki, S. R., Suzen, Y. B., Huang, P. G., and Volker, S., 2006, ASME J. Turbomach., 128(3), pp. 423–434) of the paper details a significant number of test cases that have been used to validate the transition model for turbomachinery and aerodynamic applications. The authors believe that the current formulation is a significant step forward in engineering transition modeling, as it allows the combination of correlation-based transition models with general purpose CFD codes.
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TL;DR: The main goal of the present paper is to publish the full model and release it to the research community so that it can continue to be further validated and possibly extended or improved.
Abstract: A new correlation-based transition model has been developed, which is built strictly on local variables. As a result, the transition model is compatible with modern computational fluid dynamics techniques such as unstructured grids and massively parallel execution. The model is based on two transport equations, one for intermittency and one for a transition onset criterion in terms of momentum-thickness Reynolds number. A number of validation papers have been published on the basic formulation of the model. However, until now the full model correlations have not been published. The main goal of the present paper is to publish the full model and release it to the research community so that it can continue to be further validated and possibly extended or improved. Included in this paper are a number of test cases that can be used to validate the implementation of the model in a given computational fluid dynamics code. The authors believe that the current formulation is a significant step forward in engineering transition modeling, as it allows the combination of transition correlations with general-purpose computational fluid dynamics codes. There is a strong potential that the model will allow the first-order effects of transition to be included in everyday industrial computational fluid dynamics simulations.
1,073 citations
TL;DR: The role of the concepts behind the SST model in current and future CFD simulations of engineering flows is outlined and the overall turbulence modelling strategy for ANSYS computational fluid dynamics (CFD) is outlined.
Abstract: The present author was asked to provide an update on the status and the more recent developments around the shear-stress transport (SST) turbulence model for this special issue of the journal. The article is therefore not intended as a comprehensive overview of the status of engineering turbulence modelling in general, nor on the overall turbulence modelling strategy for ANSYS computational fluid dynamics (CFD) in particular. It is clear from many decades of turbulence modelling that no single model-nor even a single modelling approach-can solve all engineering flows. Any successful CFD code will therefore have to offer a wide range of models from simple Eddy-viscosity models through second moment closures all the way to the variety of unsteady modelling concepts currently under development. This article is solely intended to outline the role of the concepts behind the SST model in current and future CFD simulations of engineering flows.
693 citations
TL;DR: An incremental approach was used to validate the model, first on 2D flat plates and airfoils and then on to progressively more complicated test cases such as a three-element flap, a 3D transonic wing and a full helicopter configuration, and good agreement with the available experimental data was observed.
Abstract: The paper addresses modelling concepts based on the RANS equations for laminar-turbulent transition prediction in general-purpose CFD codes. Available models are reviewed, with emphasis on their compatibility with modern CFD methods. Requirements for engineering transition models suitable for industrial CFD codes are specified. A new concept for transition modeling is introduced. It is based on the combination of experimental correlations with locally formulated transport equations. The concept is termed LCTM – Local Correlation-based Transition Model. An LCTM model, which satisfies most of the specified requirements is described, including results for a variety of different complex applications. An incremental approach was used to validate the model, first on 2D flat plates and airfoils and then on to progressively more complicated test cases such as a three-element flap, a 3D transonic wing and a full helicopter configuration. In all cases good agreement with the available experimental data was observed. The authors believe that the current formulation is a significant step forward in engineering transition modeling, as it allows the combination of transition correlations with general purpose CFD codes. There is a strong potential that the model will allow the 1st order effects of transition to be included in everyday industrial CFD simulations.
519 citations
Cites background or methods from "A Correlation-Based Transition Mode..."
...The model given in Menter et al. [ 16 ] and Langtry et al. [6] has been developed in a joint project between GE Global Research, ANSYS-CFX and the University of Kentucky....
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...The major numerical and modelling deficiencies associated with that prototype model have been eliminated by Menter et al. [ 16 ] and a wide range of turbomachinery-relatedflow problems has been computed by Langtry et al. [6]....
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...The entire infrastructure of the formulation is given in Menter et al. [ 16 ] and will be repeated below....
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...The cases are described in more detail in Menter et al. [ 16 ], Langtry et al. [6] and Langtry and Menter [7], including grid refinement and sensitivity studies....
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TL;DR: In this article, an eddy-viscosity turbulence model employing three additional transport equations is presented and applied to a number of transitional flow test cases, which is based on the k- framework and represents a substantial refinement to a transition-sensitive model that has been previously documented in the open literature.
Abstract: An eddy-viscosity turbulence model employing three additional transport equations is presented and applied to a number of transitional flow test cases. The model is based on the k- framework and represents a substantial refinement to a transition-sensitive model that has been previously documented in the open literature. The third transport equation is included to predict the magnitude of low-frequency velocity fluctuations in the pretransitional boundary layer that have been identified as the precursors to transition. The closure of model terms is based on a phenomenological (i.e., physics-based) rather than a purely empirical approach and the rationale for the forms of these terms is discussed. The model has been implemented into a commercial computational fluid dynamics code and applied to a number of relevant test cases, including flat plate boundary layers with and without applied pressure gradients, as well as a variety of airfoil test cases with different geometries, Reynolds numbers, freestream turbulence conditions, and angles of attack. The test cases demonstrate the ability of the model to successfully reproduce transitional flow behavior with a reasonable degree of accuracy, particularly in comparison with commonly used models that exhibit no capability of predicting laminar-toturbulent boundary layer development. While it is impossible to resolve all of the complex features of transitional and turbulent flows with a relatively simple Reynolds-averaged modeling approach, the results shown here demonstrate that the new model can provide a useful and practical tool for engineers addressing the simulation and prediction of transitional flow behavior in fluid systems. DOI: 10.1115/1.2979230
508 citations
TL;DR: Menter et al. as mentioned in this paper proposed a new correlation-based transition model based on local variables, which is compatible with modern computational fluid dynamics (CFD) methods using unstructured grids and massive parallel execution.
Abstract: A new correlation-based transition model has been developed, which is built strictly on local variables. As a result, the transition model is compatible with modern computational fluid dynamics (CFD) methods using unstructured grids and massive parallel execution. The model is based on two transport equations, one for the intermittency and one for the transition onset criteria in terms of momentum thickness Reynolds number. The proposed transport equations do not attempt to model the physics of the transition process (unlike, e.g., turbulence models), but form a framework for the implementation of correlation-based models into general-purpose CFD methods. Part I of this paper (Menter, F. R., Langtry, R. B., Likki, S. R., Suzen, Y. B., Huang, P. G., and Volker, S., 2006, ASME J. Turbomach., 128(3), pp. 413–422) gives a detailed description of the mathematical formulation of the model and some of the basic test cases used for model validation. Part II (this part) details a significant number of test cases that have been used to validate the transition model for turbomachinery and aerodynamic applications, including the drag crisis of a cylinder, separation-induced transition on a circular leading edge, and natural transition on a wind turbine airfoil. Turbomachinery test cases include a highly loaded compressor cascade, a low-pressure turbine blade, a transonic turbine guide vane, a 3D annular compressor cascade, and unsteady transition due to wake impingement. In addition, predictions are shown for an actual industrial application, namely, a GE low-pressure turbine vane. In all cases, good agreement with the experiments could be achieved and the authors believe that the current model is a significant step forward in engineering transition modeling.
436 citations
References
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TL;DR: In this paper, two new two-equation eddy-viscosity turbulence models are presented, which combine different elements of existing models that are considered superior to their alternatives.
Abstract: Two new two-equation eddy-viscosity turbulence models will be presented. They combine different elements of existing models that are considered superior to their alternatives. The first model, referred to as the baseline (BSL) model, utilizes the original k-ω model of Wilcox in the inner region of the boundary layer and switches to the standard k-e model in the outer region and in free shear flows. It has a performance similar to the Wilcox model, but avoids that model's strong freestream sensitivity
15,459 citations
Book•
01 Jan 1993
TL;DR: In this paper, the authors proposed a compressible ecoulement for compressible ECCs, based on the disquette reference record created on 2005-11-18, modified on 2016-08-08.
Abstract: Keywords: ecoulement : compressible Note: + disquette Reference Record created on 2005-11-18, modified on 2016-08-08
7,023 citations
TL;DR: In this paper, the natural transition of boundary layers is investigated for a flat plate in a low-speed wind tunnel with free-stream turbulence intensities ranging from 0.3 to 5 per cent.
Abstract: Natural transition of boundary layers is investigated for a flat plate in a low-speed wind tunnel with free-stream turbulence intensities ranging from 0.3 to 5 per cent, and with pressure-gradient ...
727 citations
01 Apr 1943
TL;DR: In this article, an account of an investigation in which oscillations were discovered in the laminar boundary layer along a flat plate is given. But the oscillations are found during the course of an experiment in which transition from Laminar to turbulent flow was being studied on the plate as the turbulence in the wind stream was being reduced to unusually low values by means of damping screens.
Abstract: This is an account of an investigation in which oscillations were discovered in the laminar boundary layer along a flat plate. These oscillations were found during the course of an experiment in which transition from laminar to turbulent flow was being studied on the plate as the turbulence in the wind stream was being reduced to unusually low values by means of damping screens. The first part of the paper deals with experimental methods and apparatus, measurements of turbulence and sound, and studies of transition. A description is then given of the manner in which oscillations were discovered and how they were found to be related to transition, and then how controlled oscillations were produced and studied in detail.
571 citations