Imperial College London
Alternate

ProfessorMatthewPiggott

Faculty of Engineering, Department of Earth Science & Engineering

Professor of Computational Geoscience and Engineering
 
 
 
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Contact

 

m.d.piggott Website

 
 
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Location

 

4.82Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Pan:2020:10.1016/j.ocemod.2020.101634,
author = {Pan, W and Kramer, S and Kärnä, T and Piggott, M},
doi = {10.1016/j.ocemod.2020.101634},
journal = {Ocean Modelling},
title = {Comparing non-hydrostatic extensions to a discontinuous finite element coastal ocean model},
url = {http://dx.doi.org/10.1016/j.ocemod.2020.101634},
volume = {151},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The unstructured mesh, discontinuous Galerkin finite element discretisation based coastal ocean model, Thetis, has been extended to include non-hydrostatic (buoyancy-driven and free surface) dynamics. Two alternative approaches to achieve this are described in this work. The first (a 3D based algorithm) makes use of prismatic element based meshes and uses a split-step pressure projection method for baroclinic and barotropic modes, while the second (a 2D based algorithm) adopts a novel multi-layer approach to convert a 3D problem into a combination of multiple 2D computations with only 2D triangle meshes required. Model development is carried out at high-level with the Firedrake library, using code generation techniques to automatically produce low-level code for the discretised model equations in an efficient and rapid manner. Through comparisons against several barotropic/baroclinic test cases where non hydrostatic effects are important, the implemented approaches are verified and validated, and the proposed algorithms compared. Depending on whether the problems are dominated by dispersive, baroclinic or barotropic features, recommendation are given over the use of full 3D or multi-layer 2D based approaches to achieve optimal computational accuracy and efficiency. It is demonstrated that while in general the 2D approach is well-suited for barotropic problems and dispersive free surface waves, the 3D approach is more advantageous for simulating baroclinic buoyancy-driven flows due in part to the high vertical resolution typically required to represent the active tracer fields. Keywords: Discontinuous Galerkin, Finite element, Unstructured mesh, Baroclinic flow, Non-hydrostatic, Dispersion, Free surface
AU  - Pan,W
AU  - Kramer,S
AU  - Kärnä,T
AU  - Piggott,M
DO  - 10.1016/j.ocemod.2020.101634
PY  - 2020///
SN  - 1463-5003
TI  - Comparing non-hydrostatic extensions to a discontinuous finite element coastal ocean model
T2  - Ocean Modelling
UR  - http://dx.doi.org/10.1016/j.ocemod.2020.101634
UR  - http://hdl.handle.net/10044/1/78578
VL  - 151
ER  -
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