Abstract
In marine offshore engineering, cost-efficient simulation of unsteady water wavesand their nonlinear interaction with bodies are important to address a broad range of engineeringapplications at increasing fidelity and scale. We consider a fully nonlinear potential flow (FNPF)model discretized using a Galerkin spectral element method to serve as a basis for handling both wavepropagation and wave-body interaction with high computational efficiency within a single modellingapproach. We design and propose an efficient O(n)-scalable computational procedure based ongeometric p-multigrid for solving the Laplace problem in the numerical scheme. The fluid volume andthe geometric features of complex bodies is represented accurately using high-order polynomial basisfunctions and unstructured meshes with curvilinear prism elements. The new p-multigrid spectralelement model can take advantage of the high-order polynomial basis and thereby avoid generating ahierarchy of geometric meshes with changing number of elements as required in geometric h-multigridapproaches. We provide numerical benchmarks for the algorithmic and numerical efficiency of theiterative geometric p-multigrid solver. Results of numerical experiments are presented for wavepropagation and for wave-body interaction in an advanced case for focusing design waves interactingwith a FPSO. Our study shows, that the use of iterative geometric p-multigrid methods for theLaplace problem can significantly improve run-time efficiency of FNPF simulators
Original language | English |
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Journal | International Journal for Numerical Methods in Fluids |
Volume | 93 |
Issue number | 9 |
Pages (from-to) | 2823-2841 |
ISSN | 0271-2091 |
DOIs | |
Publication status | Published - 2021 |
Keywords
- High-order numerical method
- Spectral element method
- Fully nonlinear potential flow
- Laplace problem
- Geometric p-multigrid
- Marine offshore hydrodynamics