On the accuracy, robustness and performance of high order interpolation schemes for the overset method on unstructured grids
On the accuracy, robustness and performance of high order interpolation schemes for the overset method on unstructured grids
A comprehensive study on interpolation schemes used in overset grid techniques is here presented. Based on a literature review, numerous schemes are implemented, and their robustness, accuracy, and performance are assessed. Two code verification exercises are performed for this purpose: a 2D analytical solution of a laminar Poiseuille steady flow; and an intricate manufactured solution of a turbulent flow case, characteristic of a boundary layer flow combined with an unsteady separation bubble. For both cases, the influence of grid layouts, grid refinement, and time-step is investigated. Local and global errors, convergence orders, and mass imbalance are quantified. In terms of computational performance, strong scalability, cpu timings, load imbalancing, and domain connectivity information (DCI) overhead are reported. The effect of the overset-grid interpolation schemes on the numerical performance of the solver, that is, number of nonlinear iterations, is also scrutinized. The results show that, for a second order finite volume code, once diffusion is dominant (low Reynolds number), interpolation schemes higher than second order, for example, least squares of degree 2, are needed not to increase the total discretization errors. For convection dominated flows (high Reynolds numbers), the results suggest that second order schemes, for example, nearest cell gradient, are sufficient to prevent overset grid schemes to taint the underlying discretization errors. In terms of performance, by single-process and parallel communication optimization, the total overset-grid overhead (with DCI done externally to the CFD code) may be less than 4% of the total run time for second-order schemes and 8% for third-order ones, therefore empowering higher-order schemes and more accurate solutions.
3D URANS, Code Verification, Computational Performance, Manufactured Solution, Overset Grids
152-187
Lemaire, Sebastien
05986dec-3675-41f4-b9a4-ae4036390d6b
Vaz, Guilherme
2ee9efb8-153d-4f45-a047-7d23f7fbab5c
Deij - van Rijswijk, Menno
0723e760-ff62-4a50-827f-e7efa3788a18
Turnock, Stephen
d6442f5c-d9af-4fdb-8406-7c79a92b26ce
29 September 2021
Lemaire, Sebastien
05986dec-3675-41f4-b9a4-ae4036390d6b
Vaz, Guilherme
2ee9efb8-153d-4f45-a047-7d23f7fbab5c
Deij - van Rijswijk, Menno
0723e760-ff62-4a50-827f-e7efa3788a18
Turnock, Stephen
d6442f5c-d9af-4fdb-8406-7c79a92b26ce
Lemaire, Sebastien, Vaz, Guilherme, Deij - van Rijswijk, Menno and Turnock, Stephen
(2021)
On the accuracy, robustness and performance of high order interpolation schemes for the overset method on unstructured grids.
International Journal for Numerical Methods in Fluids, 94 (2), .
(doi:10.1002/fld.5050).
Abstract
A comprehensive study on interpolation schemes used in overset grid techniques is here presented. Based on a literature review, numerous schemes are implemented, and their robustness, accuracy, and performance are assessed. Two code verification exercises are performed for this purpose: a 2D analytical solution of a laminar Poiseuille steady flow; and an intricate manufactured solution of a turbulent flow case, characteristic of a boundary layer flow combined with an unsteady separation bubble. For both cases, the influence of grid layouts, grid refinement, and time-step is investigated. Local and global errors, convergence orders, and mass imbalance are quantified. In terms of computational performance, strong scalability, cpu timings, load imbalancing, and domain connectivity information (DCI) overhead are reported. The effect of the overset-grid interpolation schemes on the numerical performance of the solver, that is, number of nonlinear iterations, is also scrutinized. The results show that, for a second order finite volume code, once diffusion is dominant (low Reynolds number), interpolation schemes higher than second order, for example, least squares of degree 2, are needed not to increase the total discretization errors. For convection dominated flows (high Reynolds numbers), the results suggest that second order schemes, for example, nearest cell gradient, are sufficient to prevent overset grid schemes to taint the underlying discretization errors. In terms of performance, by single-process and parallel communication optimization, the total overset-grid overhead (with DCI done externally to the CFD code) may be less than 4% of the total run time for second-order schemes and 8% for third-order ones, therefore empowering higher-order schemes and more accurate solutions.
Text
slemaire_etal_Interpolation_Overset
- Accepted Manuscript
More information
Accepted/In Press date: 22 September 2021
Published date: 29 September 2021
Additional Information:
Funding Information:
This research was financially supported by the EPSRC Centre for Doctoral Training in Next Generation Computational Modelling (EP/L015382/1) at the University of Southampton including financial support from MARIN. The authors acknowledge the use of the IRIDIS High Performance Computing Facility, and associated support services at the University of Southampton as well as MARIN HPC Marclus4 and WavEC resources and facilities, in the completion of this work.
Publisher Copyright:
© 2021 John Wiley & Sons Ltd.
Keywords:
3D URANS, Code Verification, Computational Performance, Manufactured Solution, Overset Grids
Identifiers
Local EPrints ID: 451635
URI: http://eprints.soton.ac.uk/id/eprint/451635
ISSN: 0271-2091
PURE UUID: b5f918bb-33e2-4cf9-a77a-271ade4276e6
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Date deposited: 15 Oct 2021 16:33
Last modified: 17 Mar 2024 06:51
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Contributors
Author:
Sebastien Lemaire
Author:
Guilherme Vaz
Author:
Menno Deij - van Rijswijk
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