Session: 09-02-02 Wave Energy: Hydrodynamics 2

Paper Number: 127995

127995 - Case Studies of BEM Solver Accuracy With the Open-Source Code Capytaine 

The current paper discusses recent developments and enhancements in Capytaine, an open-source Python-based Boundary Element Method (BEM) program designed to simulate wave-structure interactions employing potential flow theory. These enhancements aim to improve the stability and accuracy of Capytaine, particularly in problems involving complex geometries and/or slender structures. The study first conducts a benchmark comparison between Capytaine with other well-known BEM solvers including NEMOH, HAMS, and WAMIT. These solvers are used to numerically obtain velocity potential solutions in the frequency domain. There are two primary approaches among these solvers. NEMOH and Capytaine use the source (indirect) formulation, while HAMS and WAMIT use Green's theorem for a direct solution to the velocity potential (direct formulation). Both methods involve numerically determining solutions for the integral of the Green's function and/or its derivatives. For the comparisons, three case studies are considered including the truncated cylinder, the truncated cylinder with heave plate, and multi-bodies. The results from these case studies inform a discussion on the relative advantages and disadvantages of these programs compared to Capytaine. Subsequently, the paper highlights the enhancements made to Capytaine. These include the incorporation of the direct formulation approach and the ability to define the density of the interpolation table (tabulation) for approximating the Green's function, following Delhommeau's formulas.  

Presenting Author: Nhu Nguyen Sandia

Presenting Author Biography: Nhu Nguyen is currently a Postdoctoral Researcher in the Water Power Technology at Sandia National Laboratories. She obtained her Bachelor and PhD in Mechanical Engineering from Cornell University and University of Massachusetts Amherst, respectively. Her graduate research focused on fluid-structure interactions and nonlinear behaviors of highly flexible cable dynamics with the applications in mooring systems for offshore platforms. At Sandia, Nhu is involved in developing and supporting theoretical and numerical modeling of resource characterizations; performances of marine and hydrokinetic systems; as well as their influences on the surrounding environment.

Authors:

Matthieu Ancellin Eurobios Mews Labs
Nhu Nguyen Sandia