This paper presents a reformulated version of the author'sk-ω model of turbulence. Revisions include the addition of just one new closure coefficient and an adjustment to the dependence of eddy viscosity on turbulence properties. The result is a significantly improved model that applies to both boundary layers and free shear flows and that has very little sensitivity to finite freestream boundary conditions on turbulence properties. The improvements to the k-ω model facilitate a significant expansion of its range of applicability. The new model, like preceding versions, provides accurate solutions for mildly separated flows and simple geometries such as that of a backward-facing step. The model's improvement over earlier versions lies in its accuracy for even more complicated separated flows. This paper demonstrates the enhanced capability for supersonic flow into compression corners and a hypersonic shock-wave/ boundary-layer interaction. The excellent agreement is achieved without introducing any compressibility modifications to the turbulence model.

Formulation of the k-w Turbulence Model Revisited

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.

Review of the shear-stress transport turbulence model experience from an industrial perspective

50 years of Computational Wind Engineering: Past, present and future

The development and preliminary validation of a new k-ω turbulence model based on explicit algebraic Reynolds-stress modeling are presented. This new k-ω model is especially designed for the requirements typical in high-lift aerodynamics. Attention is especially paid to the model behavior at the turbulent/laminar edges, to the model sensitivity to pressure gradients, and to the calibration of the model coefficients for appropriate flow phenomena. The model development is based on both analytical studies and numerical experimenting. The developed model is assessed and validated for a set of realistic flow problems including high-lift airfoil flows.

New Advanced k-w Turbulence Model for High-Lift Aerodynamics

The second AIAA CFD High-Lift Prediction Workshop was held in San Diego, California, in June 2013. The goals of the workshop continued in the tradition of the first high-lift workshop: to assess the numerical prediction capability of current-generation computational fluid dynamics (CFD) technology for swept, medium/high-aspect-ratio wings in landing/takeoff (high-lift) configurations. This workshop analyzed the flow over the DLR-F11 model in landing configuration at two different Reynolds numbers. Twenty-six participants submitted a total of 48 data sets of CFD results. A variety of grid systems (both structured and unstructured) were used. Trends due to grid density and Reynolds number were analyzed, and effects of support brackets were also included. This paper analyzes the combined results from all workshop participants. Comparisons with experimental data are made. A statistical summary of the CFD results is also included.

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Overview and Summary of the Third AIAA High Lift Prediction Workshop.

Some improvements in Menter's k-omega SST turbulence model

This paper introduces an improved computational method for predicting the behaviour of turbulent flows over rough surfaces. The method is based on the numerical solution of the Navier-Stokes equations employing the k - w-SST turbulence model. An existing surface-roughness method, developed for the traditional k — w models, was found to not work well with the SST-model. In this work, the SST-model is suitably modified and extended through the incorporation of the surface-roughness method into it. The theoretical background is briefly discussed and computational results for flat plate and an aerofoil section obtained by the new method are presented.

Extension of the k-omega-SST turbulence model for flows over rough surfaces

We propose a modification to the κ-ω SST turbulence model. Through the modification, the range of applicability of the model is extended to flows involving rough surfaces. The surface roughness is simulated by adjusting the surface value of ω

Antti Hellsten

Papers

New Advanced k-w Turbulence Model for High-Lift Aerodynamics

Some improvements in Menter's k-omega SST turbulence model

Extension of the k-omega-SST turbulence model for flows over rough surfaces

Extension of k- W Shear-Stress Transport Turbulence Model for Rough-Wall Flows

New Advanced k-w Turbulence Model for High-Lift Aerodynamics