Effects of reconstruction of variables on the accuracy and computational performance of upscaling solutions of the shallow water equations
Effects of reconstruction of variables on the accuracy and computational performance of upscaling solutions of the shallow water equations
This paper presents a new sub-grid flood inundation model obtained by upscaling the shallow water equations (SWE) to enhance the model efficiency in large-scale problems. The model discretizes study domains using two nested meshes. The equations are solved at the coarse mesh by a second-order accurate in space (i.e. piecewise linear reconstruction of variables) Godunov-type finite volume (FV) method, while the fine mesh is used to incorporate high-resolution topography and roughness into the solution. The accuracy and performance of the model were compared against a first-order version of the model recently proposed by the authors and a second-order conventional FV model using artificial and real-world test problems. Results showed that improved accuracy is delivered by the proposed model, and that at low-resolution meshes, the spatial reconstruction of variables of the numerical scheme plays a major role in the solution's accuracy.
2D shallow water equations, finite volume, flooding, nested meshes, solution upscaling and downscaling, sub-grid
409-421
Shamkhalchian, Alireza
3f3c8717-572c-44af-be0a-d720731cdb55
De Almeida, Gustavo
f6edffc1-7bb3-443f-8829-e471b6514a7e
Shamkhalchian, Alireza
3f3c8717-572c-44af-be0a-d720731cdb55
De Almeida, Gustavo
f6edffc1-7bb3-443f-8829-e471b6514a7e
Shamkhalchian, Alireza and De Almeida, Gustavo
(2023)
Effects of reconstruction of variables on the accuracy and computational performance of upscaling solutions of the shallow water equations.
Journal of Hydraulic Research, 61 (3), .
(doi:10.1080/00221686.2023.2201210).
Abstract
This paper presents a new sub-grid flood inundation model obtained by upscaling the shallow water equations (SWE) to enhance the model efficiency in large-scale problems. The model discretizes study domains using two nested meshes. The equations are solved at the coarse mesh by a second-order accurate in space (i.e. piecewise linear reconstruction of variables) Godunov-type finite volume (FV) method, while the fine mesh is used to incorporate high-resolution topography and roughness into the solution. The accuracy and performance of the model were compared against a first-order version of the model recently proposed by the authors and a second-order conventional FV model using artificial and real-world test problems. Results showed that improved accuracy is delivered by the proposed model, and that at low-resolution meshes, the spatial reconstruction of variables of the numerical scheme plays a major role in the solution's accuracy.
Text
Alireza_paper_2
- Accepted Manuscript
More information
Accepted/In Press date: 23 February 2023
e-pub ahead of print date: 25 May 2023
Additional Information:
Publisher Copyright:
© 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
Keywords:
2D shallow water equations, finite volume, flooding, nested meshes, solution upscaling and downscaling, sub-grid
Identifiers
Local EPrints ID: 476689
URI: http://eprints.soton.ac.uk/id/eprint/476689
ISSN: 0022-1686
PURE UUID: b389ceba-e252-484d-85b4-97015aa4b8aa
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Date deposited: 11 May 2023 16:43
Last modified: 30 Aug 2023 01:44
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