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

Paper Number: 125573

125573 - Advancing the Modelica™ Ocean Engineering Toolbox With the Capability to Generate Accurate Wave Excitation Forces 

The Ocean Engineering Toolbox (OET) is an open-source, Modelica^TM compliant symbolic library capable of simulating the dynamic motions of floating bodies subject to polychromatic, unidirectional waves. This paper presents recent advancements in the OET: (1) development of custom components to represent the frequency-dependent wave excitation force, and (2) significant improvements in the toolbox’s computational performance. While the Modelica language can represent complex cyber-physical systems efficiently, the primary challenges with modelling wave induced floating bodiesare: (1) non-compatibility with frequency-dependent variables, (2) lack of hydrodynamic components in the Modelica Standard Library (MSL), and (3) integration with older versions of the OET. Implemented in the time-domain, surface elevation profiles can now be generated for both regular and irregular waves, with three spectral options for polychromatic seas: Pierson-Moskowitz, Brettschneider, and JONSWAP. Hydrodynamic coefficients are imported using a MATLAB script to process the output from Boundary Element Method (BEM) codes. A novel symbolic implementation of the spectral decomposition and interpolation is presented in this work to generate the frequency-dependent excitation force in Modelica. Results from the OET are compared against data generated from WEC-Sim, validating both the wave excitation force and the corresponding system dynamic response for a floating point-absorber in heave. These advancements translate to improved simulation accuracy and computational performance, while advancing the overall hydrodynamic modelling capabilities in Modelica.

Presenting Author: Ajay Menon Sys-MoDEL

Presenting Author Biography: Ajay Menon is a wave energy researcher at Buogra Ltd., a Hong Kong-based renewable energy firm. He leads the hydrodynamics team designing a commercial line attenuator WEC for deployment in the Philippines. With experience in developing robust simulation tools for ocean engineering applications, he works with the Sys-MoDEL academic research group at the University of New Brunswick. As a visiting researcher, Ajay is the principal investigator in an ongoing project to develop a Modelica toolbox to simulate floating WECs. He is a 2023 Dual Degree graduate from IIT Kharagpur with a major in Ocean Engineering and an Economics minor.

Authors:

Ajay Menon Sys-MoDEL
Ali Shahbaz Haider University of New Brunswick
Kush Bubbar University of New Brunswick