Parallel adaptive mesh refinement for large-eddy simulations of turbulent flows

Antepara, Oscar; Lehmkuhl, O.; Borrell, R.; Chiva, J.; Oliva, A.

doi:10.1016/j.compfluid.2014.09.050

Cited by 40 publications

(39 citation statements)

References 34 publications

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“…In case of using Cartesian meshes, the adaptive mesh refinement strategy (AMR) is used to reduce consistently the grid spacing in the vicinity of the interface, thus, allowing an accurate representation of interface phenomena, both at the interface between liquid and gas and between fluids and solid. In particular, the quad/octree algorithm proposed by Antepara et al [13] and extended to multiphase flows in previous works [17,18] is here used. The strategy includes a particular treatment of the mass fluxes which allows the exact conservation of mass, momentum and kinetic energy (key element for the correct resolution of turbulent flows [19]).…”

Section: Adaptive Mesh Refinementmentioning

confidence: 99%

“…The interface tracking is carried-out by means of a conservative LS method [11], while the interaction between solid and liquid is solved by means of direct forcing IBM [12]. An adaptive mesh refinement strategy (AMR) [13] is adopted in order to dynamically improve the mesh definition in the interface region and in zones where the basic mesh size is not sufficient to correctly solve the turbulent scales or the interfacial characteristic lengths. After presenting the numerical framework in Section 2, we propose two simple validation tests in Section 3.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical study of an impulse wave generated by a sliding mass

Schillaci¹,

Favre²,

Antepara³

et al. 2017

Int. J. CMEM

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© 2018 WIT PressIn this work, a numerical framework for the direct numerical simulation of tsunami waves generated by landslide events is proposed. The method, implemented on the TermoFluids numerical platform, adopts a free surface model for the simulation of momentum equations; thus, considering the effect of air on the flow physics negligible. The effect of the solid motion on the flow is taken into account by means of a direct forcing immersed boundary method (IBM).\ud The method is available for 3-D unstructured meshes; however, it can be integrated with an adaptive mesh refinement (AMR) tool to dynamically increase the local definition of the mesh in the vicinity of the interfaces, which separate the phases or in the presence of vortical structures.\ud The method is firstly validated by simulating the entrance of objects into still water surfaces for 2-D and 3-D configurations. Next, the case of tsunami generation from a subaerial landslide is studied and the results are validated by comparison to experimental and numerical measurements. Overall, the model demonstrates its efficiency in the simulation of this type of physics, and a wide versatility in the choice of the domain discretization.Peer ReviewedPostprint (published version

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Section: Adaptive Mesh Refinementmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Numerical study of an impulse wave generated by a sliding mass

Schillaci¹,

Favre²,

Antepara³

et al. 2017

Int. J. CMEM

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show abstract

“…We now briefly recall some of the recent works on unstructured grid methods. Antepara et al proposed a parallel adaptive mesh refinement strategy for LESs that achieves a parallel efficiency of 90% on 256 CPU‐cores. Su and Yu studied a parallel finite volume method for the LES of turbulent flows around the side mirror of a car.…”

Section: Introductionmentioning

confidence: 99%

A parallel implicit domain decomposition algorithm for the large eddy simulation of incompressible turbulent flows on 3D unstructured meshes

Liao

Chen

Yan

et al. 2018

Numerical Methods in Fluids

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Summary We present a parallel fully implicit algorithm for the large eddy simulation (LES) of incompressible turbulent flows on unstructured meshes in three dimensions. The LES governing equations are discretized by a stabilized Galerkin finite element method in space and an implicit second‐order backward differentiation scheme in time. To efficiently solve the resulting large nonlinear systems, we present a highly parallel Newton‐Krylov‐Schwarz algorithm based on domain decomposition techniques. Analytic Jacobian is applied in order to obtain the best achievable performance. Two benchmark problems of lid‐driven cavity and flow passing a square cylinder are employed to validate the proposed algorithm. We then apply the algorithm to the LES of turbulent flows passing a full‐size high‐speed train with realistic geometry and operating conditions. The numerical results show that the algorithm is both accurate and efficient and exhibits a good scalability and parallel efficiency with tens of millions of degrees of freedom on a computer with up to 4096 processors. To understand the numerical behavior of the proposed fully implicit scheme, we study several important issues, including the choices of linear solvers, the overlapping size of the subdomains, and, especially, the accuracy of the Jacobian matrix. The results show that an exact Jacobian is necessary for the efficiency and the robustness of the proposed LES solver.

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“…The adaptive mesh refinement (AMR) strategy can be used to automatically modify the mesh density at much reduced cost compared to manually remeshing or the costly global mesh refinement. From the seminal work of Berger et al, [1][2][3] continuous researches have be conducted in this field and AMR has its wide application in many fields, including aerodynamics, [4][5][6][7] astrophysics, 8 combustion, 9,10 diffraction gratings, 11,12 electronic structures, 13,14 multiphase flow, 15,16 and many others. The AMR based on the Cartesian grid is most widely studied in the literature.…”

Section: Introductionmentioning

confidence: 99%

A high‐order element based adaptive mesh refinement strategy for three‐dimensional unstructured grid

Gou

Yuan

Chen

2017

Numerical Methods in Fluids

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Summary Adaptive mesh refinement (AMR) shows attractive properties in automatically refining the flow region of interest, and with AMR, better prediction can be obtained with much less labor work and cost compared to manually remeshing or the global mesh refinement. Cartesian AMR is well established; however, AMR on hybrid unstructured mesh, which is heavily used in the high‐Reynolds number flow simulation, is less matured and existing methods may result in degraded mesh quality, which mostly happens in the boundary layer or near the sharp geometric features. User intervention or additional constraints, such as freezing all boundary layer elements or refining the whole boundary layer, are required to assist the refinement process. In this work, a novel AMR strategy is developed to handle existing difficulties. In the new method, high‐order unstructured elements are first generated based on the baseline mesh; then the refinement is conducted in the parametric space; at last, the mesh suitable for the solver is output. Generating refined elements in the parametric space with high‐order elements is the key of this method and this helps to guarantee both the accuracy and robustness. With the current method, 3‐dimensional hybrid unstructured mesh of huge size and complex geometry can be automatically refined, without user intervention nor additional constraints. With test cases including the 2‐dimensional airfoil and 3‐dimensional full aircraft, the current AMR method proves to be accurate, simple, and robust.

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Parallel adaptive mesh refinement for large-eddy simulations of turbulent flows

Abstract: In this paper a parallel adaptive mesh refinement (AMR) strategy for large and accuracy of our methodology is shown on the numerical simulation of the turbulent flow around a square cylinder at Re = 22000 and the turbulent flow around two side-by-side square cylinders at Re = 21000.

Cited by 40 publications

References 34 publications

Numerical study of an impulse wave generated by a sliding mass

Numerical study of an impulse wave generated by a sliding mass

A parallel implicit domain decomposition algorithm for the large eddy simulation of incompressible turbulent flows on 3D unstructured meshes

A high‐order element based adaptive mesh refinement strategy for three‐dimensional unstructured grid

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