Finite-Element Solutions for Turbulent Flow over the NACA 0012 Airfoil (Invited)

Anderson, W. Kyle; Ahrabi, Behzad Reza; Newman, James C.

doi:10.2514/6.2015-1531

Cited by 8 publications

(3 citation statements)

References 30 publications

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“…Results from the present study are compared with those from the Turbulence Modeling Resource (TMR) website [68]. In a previous study [77], we compared the forces, moments, pressure distributions, skin friction, and profiles of velocity components as well as turbulence working variable between the developed SUPG scheme and the finite-volume solutions obtained using FUN3D [78][79][80] and CFL3D flow solvers. It was demonstrated that for most of the comparisons the proposed SUPG scheme obtains similar results as the finite-volume schemes but using less DOFs, and also SUPG solutions demonstrates significantly less dissipation of the wake profiles downstream of the airfoil.…”

Section: Subsonic Turbulent Flow Over Naca0012mentioning

confidence: 99%

An Adjoint-Based hp-Adaptive Petrov-Galerkin Method for Turbulent Flows

Ahrabi

Anderson

Newman

2015

22nd AIAA Computational Fluid Dynamics Conference

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In this study, an adjoint-based hp-adaptation algorithm has been developed within a Petrov-Galerkin finite-element method. The developed mesh adaptation algorithm is able to perform non-conformal mesh adaptations. To consistently account for hanging nodes, the constrained approximation method has been utilized. Hierarchical basis functions have been employed to facilitate the implementation of the constrained approximation. The methodology has been demonstrated on numerous cases using the Euler and Reynolds Average Navier-Stokes (RANS) equations, equipped with a modified SpalartAllmaras (SA) turbulence model. Also, a PDE-based artificial viscosity has been added to the governing equations, to stabilize the solution in the vicinity of shock waves. For accurate representation of the geometric surfaces, high-order curved boundary meshes have been generated and the interior meshes have been deformed through the solution of a modified linear elasticity equation. Fully implicit linearization has been used to advance the solution toward a steady-state. Dirichlet boundary conditions have been imposed weakly and the functional outputs have been modified according to the weak boundary conditions in order to provide a smooth adjoint solution near the boundaries.To accelerate the error reduction in presence of singularity points, an enhanced hrefinement, based on solution's smoothness, has been used. Numerical results illustrate consistent accuracy improvement of the functional outputs for both h-and hpadaptation, and also capability enhancement in capturing complex viscous effects such as shock-wave/turbulent boundary layer interaction.

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Section: Subsonic Turbulent Flow Over Naca0012mentioning

confidence: 99%

An Adjoint-Based hp-Adaptive Petrov-Galerkin Method for Turbulent Flows

Ahrabi

Anderson

Newman

2015

22nd AIAA Computational Fluid Dynamics Conference

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“…Although a far-field point vortex boundary condition correction [32] is recommended at the TMR Web site [1], the following results are presented without such a correction. This simplification facilitates comparisons with emerging high-order and mesh adaptation capabilities [33,34]. The far-field value of the Spalart turbulence variable isν farfield 3ν ∞ .…”

Section: A Flow Parameters Boundary Conditions and Discretization mentioning

confidence: 99%

Grid-Convergence of Reynolds-Averaged Navier–Stokes Solutions for Benchmark Flows in Two Dimensions

et al. 2016

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A detailed grid-convergence study has been conducted to establish reference solutions corresponding to the oneequation linear eddy-viscosity Spalart-Allmaras turbulence model for two-dimensional turbulent flows around the NACA 0012 airfoil and a flat plate. The study involved the three widely used codes CFL3D (NASA), FUN3D (NASA), and TAU (DLR, The German Aerospace Center), as well as families of uniformly refined structured grids that differed in the grid density patterns. Solutions computed by different codes on different grid families appeared to converge to the same continuous limit but exhibited strikingly different convergence characteristics. The grid resolution in the vicinity of geometric singularities, such as a sharp trailing edge, was found to be the major factor affecting accuracy and convergence of discrete solutions; the effects of this local grid resolution were more prominent than differences in discretization schemes and/or grid elements. The results reported for these relatively simple turbulent flows demonstrated that CFL3D, FUN3D, and TAU solutions were very similar on the finest grids used in the study, but even those grids were not sufficient to conclusively establish an asymptotic convergence order.

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“…The test cases in this section are designed primarily for numerical analysis of solver technology used in turbulent flow simulations, e.g., grid and iterative convergence properties, effects of specific discretizations, grid-refinement strategies, etc. In support of the TMR objectives, special sessions on solver technology for turbulent flows were held at the AIAA Science and Technology Forum and Exposition (SciTech) conferences in 2015 [4][5][6][7][8][9][10][11] and 2016. [12][13][14][15][16][17][18][19][20] Advanced solver technologies for the Reynolds-Averaged Navier-Stokes (RANS) equations with a one-equation linear eddyviscosity Spalart-Allmaras (SA) turbulence model 21,22 were demonstrated in application to relatively simple benchmark flows in two dimensions (2D) and three dimensions (3D).…”

Section: Introductionmentioning

confidence: 99%

Grid Convergence for Three Dimensional Benchmark Turbulent Flows

Diskin

Anderson

Pandya

et al. 2018

2018 AIAA Aerospace Sciences Meeting

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Grid convergence studies are performed to establish reference solutions for benchmark three dimensional turbulent flows in support of the ongoing turbulence model verification and validation effort at the Turbulence Modeling Resource website curated by NASA. The benchmark cases are a subsonic flow around a hemisphere cylinder and a transonic flow around the ONERA M6 wing with a sharp trailing edge. The study applies widely-used computational fluid dynamics codes developed and supported at the NASA Langley Research Center: FUN3D, USM3D, and CFL3D. Reference steady-state solutions are computed for the Reynolds-Averaged Navier-Stokes equations with the Spalart-Allmaras turbulence model on families of consistently-refined grids composed of different types of cells. Coarse-to-fine and code-to-code solution variation is described in detail.

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Finite-Element Solutions for Turbulent Flow over the NACA 0012 Airfoil (Invited)

Cited by 8 publications

References 30 publications

An Adjoint-Based hp-Adaptive Petrov-Galerkin Method for Turbulent Flows

An Adjoint-Based hp-Adaptive Petrov-Galerkin Method for Turbulent Flows

Grid-Convergence of Reynolds-Averaged Navier–Stokes Solutions for Benchmark Flows in Two Dimensions

Grid Convergence for Three Dimensional Benchmark Turbulent Flows

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