Session: 06-05-04 Marine Hydrodynamics IV

Paper Number: 126801

126801 - Application of Irregular Frequency Removal Feature in Capytaine for Marine Operations in the Offshore Wind Farms 

The offshore wind industry is one of the clean energy sectors which has grown significantly in recent years. Furthermore, an increase in the installed offshore wind farms also means an increase in the number of marine operations (e.g. installation, logistic/crew transfer, decommissioning). Marine operation plannings require hydrodynamic load estimation. Since the environmental conditions are limited in the range of operational conditions, in which extreme wave conditions are not expected, a linear potential flow solver is still a powerful tool to compute the hydrodynamic load in the operation analysis. In this paper, Capytaine, one of the open-source solvers, is utilized and developed to be able to perform typical hydrodynamic analysis in wind farm marine operations. Capytaine is a linear potential flow solver that is written as the Python library to solve diffraction and radiation problems. In this paper, an additional feature of irregular frequency removal is added. Irregular frequency is observed due to a non-unique solution in the eigenfrequency of the internal body water surface. In most cases, its appearance is within the ocean wave frequency range. The non-unique solution creates a non-smooth frequency domain estimation of the hydrodynamic coefficients and wave field estimation outside the body.  The first part of the analysis will discuss and demonstrate the problems of irregular frequency in the original version of Capytaine. Subsequently, an internal lid method is adopted in the modified version of Capytaine. The internal lid imposes additional boundary condition which is observed to remove the irregular frequency phenomena. Furthermore, it is also seen that the oscillation in the high frequency range is also smoothened due to the lid addition. Validation of this method is performed by comparing the results to the commercial solver. Afterwards, an example of marine operation aspects (e.g. flow field around a monopile and installation vessel) is provided to demonstrate the capability of modified-Capytaine. Suggestions for future development of Capytaine are also proposed at the end of the paper. The new open-source solver is foreseen to improve the accuracy of marine operation analysis and to help reduce the operational planning cost, thus aiming for affordable renewable energy.

Presenting Author: Ivandito Herdayanditya KU Leuven

Presenting Author Biography: Ivandito Herdayanditya is currently doing PhD Research at KU Leuven and Ghent University within PhairywinD Project. The project focuses on the development of the Belgian offshore wind industry. One of the research aspects of the project is related to the marine operation in the wind farm, in which Ivandito is working on. Ivandito graduated from REM, an Erasmus Joint Master Degree Program, focusing on a hydrodynamic aspect of marine renewable energy. His master's thesis was developing of in-house fully nonlinear potential code to estimate the power production of a submerged wave energy converter.

Authors:

Ivandito Herdayanditya KU Leuven
Benjamin Baert DEME Group
Florian Stempinski DEME Group
Pieter Rauwoens KU Leuven
Evert Lataire Ghent University