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Coupling of hybridisable discontinuous Galerkin and finite volumes for transient compressible flows / SANJAY SHESHACHALA

Swansea University Author: SANJAY SHESHACHALA

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DOI (Published version): 10.23889/SUthesis.58622

Abstract

Fast, high-fidelity solution workflows for transient flow phenomena is an important challenge in the computational fluid dynamics (CFD) community. Current low-order methodologies suffer from large dissipation and dispersion errors and require large mesh sizes for unsteady flow simulations. Recently,...

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Published: Swansea 2021
Institution: Swansea University
Degree level: Doctoral
Degree name: Ph.D
Supervisor: Sevilla, Ruben ; Hassan, Oubay
URI: https://cronfa.swan.ac.uk/Record/cronfa58622
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first_indexed 2021-11-11T15:59:07Z
last_indexed 2021-11-12T04:26:10Z
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spelling 2021-11-11T16:27:49.5750856 v2 58622 2021-11-11 Coupling of hybridisable discontinuous Galerkin and finite volumes for transient compressible flows ec88926d6d57bfd193e95dc929633abc SANJAY SHESHACHALA SANJAY SHESHACHALA true false 2021-11-11 Fast, high-fidelity solution workflows for transient flow phenomena is an important challenge in the computational fluid dynamics (CFD) community. Current low-order methodologies suffer from large dissipation and dispersion errors and require large mesh sizes for unsteady flow simulations. Recently, on the other hand, high-order methods have gained popularity offering high solution accuracy. But they suffer from the lack of robust, curvilinear mesh generators.A novel methodology that combines the advantages of the classical vertex-centred finite volume (FV) method and high-order hybridisable discontinuous Galerkin (HDG) method is presented for the simulation of transient inviscid compressible flows. The resulting method is capable of simulating the transient effects on coarse, unstructured meshes that are suitable to perform steady simulations with traditional low-order methods. In the vicinity of the aerodynamic shapes, FVs are used whereas in regions where the size of the element is too large for finite volumes to provide an accurate answer, the high-order HDG approach is employed with a non-uniform degree of approximation. The proposed method circumvents the need to produce tailored meshes for transient simulations, as required in a low-order context, and also the need to produce high-order curvilinear meshes, as required by high-order methods.FV and HDG methods for compressible inviscid flows with an implicit time-stepping method and capable of handling flow discontinuities is developed. A two-way coupling of the methods in a monolithic manner was achieved by the consistent application of the so-called transmission conditions at the FV-HDG interface. Numerical tests highlight the optimal convergence properties of the coupled HDG-FV scheme. Numeri-cal examples demonstrate the potential and suitability of the developed methodology for unsteady 2D and 3D flows in the context of simulating the wind gust effect on aerodynamic shapes. E-Thesis Swansea transient flows, hybridisable discontinuous Galerkin, finite volumes, coarse meshes, coupling, transmission conditions 11 11 2021 2021-11-11 10.23889/SUthesis.58622 ORCiD identifier: https://orcid.org/0000-0003-3023-2681 COLLEGE NANME COLLEGE CODE Swansea University Sevilla, Ruben ; Hassan, Oubay Doctoral Ph.D 2021-11-11T16:27:49.5750856 2021-11-11T15:55:46.3109624 Faculty of Science and Engineering School of Engineering and Applied Sciences - Uncategorised SANJAY SHESHACHALA 1 58622__21498__fe7d32d06bbf43f69534b3d493bc6d28.pdf Sheshachala_Sanjay_PhD_Thesis_Final_Redacted_Signature.pdf 2021-11-11T16:15:49.9932992 Output 31774442 application/pdf E-Thesis – open access true Copyright: The author, Sanjay Komala Sheshachala, 2021. true eng
title Coupling of hybridisable discontinuous Galerkin and finite volumes for transient compressible flows
spellingShingle Coupling of hybridisable discontinuous Galerkin and finite volumes for transient compressible flows
SANJAY SHESHACHALA
title_short Coupling of hybridisable discontinuous Galerkin and finite volumes for transient compressible flows
title_full Coupling of hybridisable discontinuous Galerkin and finite volumes for transient compressible flows
title_fullStr Coupling of hybridisable discontinuous Galerkin and finite volumes for transient compressible flows
title_full_unstemmed Coupling of hybridisable discontinuous Galerkin and finite volumes for transient compressible flows
title_sort Coupling of hybridisable discontinuous Galerkin and finite volumes for transient compressible flows
author_id_str_mv ec88926d6d57bfd193e95dc929633abc
author_id_fullname_str_mv ec88926d6d57bfd193e95dc929633abc_***_SANJAY SHESHACHALA
author SANJAY SHESHACHALA
author2 SANJAY SHESHACHALA
format E-Thesis
publishDate 2021
institution Swansea University
doi_str_mv 10.23889/SUthesis.58622
college_str Faculty of Science and Engineering
hierarchytype
hierarchy_top_id facultyofscienceandengineering
hierarchy_top_title Faculty of Science and Engineering
hierarchy_parent_id facultyofscienceandengineering
hierarchy_parent_title Faculty of Science and Engineering
department_str School of Engineering and Applied Sciences - Uncategorised{{{_:::_}}}Faculty of Science and Engineering{{{_:::_}}}School of Engineering and Applied Sciences - Uncategorised
document_store_str 1
active_str 0
description Fast, high-fidelity solution workflows for transient flow phenomena is an important challenge in the computational fluid dynamics (CFD) community. Current low-order methodologies suffer from large dissipation and dispersion errors and require large mesh sizes for unsteady flow simulations. Recently, on the other hand, high-order methods have gained popularity offering high solution accuracy. But they suffer from the lack of robust, curvilinear mesh generators.A novel methodology that combines the advantages of the classical vertex-centred finite volume (FV) method and high-order hybridisable discontinuous Galerkin (HDG) method is presented for the simulation of transient inviscid compressible flows. The resulting method is capable of simulating the transient effects on coarse, unstructured meshes that are suitable to perform steady simulations with traditional low-order methods. In the vicinity of the aerodynamic shapes, FVs are used whereas in regions where the size of the element is too large for finite volumes to provide an accurate answer, the high-order HDG approach is employed with a non-uniform degree of approximation. The proposed method circumvents the need to produce tailored meshes for transient simulations, as required in a low-order context, and also the need to produce high-order curvilinear meshes, as required by high-order methods.FV and HDG methods for compressible inviscid flows with an implicit time-stepping method and capable of handling flow discontinuities is developed. A two-way coupling of the methods in a monolithic manner was achieved by the consistent application of the so-called transmission conditions at the FV-HDG interface. Numerical tests highlight the optimal convergence properties of the coupled HDG-FV scheme. Numeri-cal examples demonstrate the potential and suitability of the developed methodology for unsteady 2D and 3D flows in the context of simulating the wind gust effect on aerodynamic shapes.
published_date 2021-11-11T04:15:17Z
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score 10.999616

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