Session: 09-02-04 Wind Energy: Moorings II

Submission Number: 157369

Damping Contributions of Semi-Taut Mooring for Floating Wind Turbines 

Proceedings of the ASME 2025 44th International

Conference on Ocean, Offshore, and Arctic Engineering

OMAE2025

June 22-27, 2025, Vancouver, Canada

Damping Contributions of Semi-taut Mooring for Floating Wind Turbines

Evans Korankye Frimpong, Kevin Pope, Xili Duan

Department of Mechanical and Mechatronics Engineering

Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador

Abstract

In this paper, the energy dissipation characteristics of a semi-taut mooring for floating offshore wind turbines are investigated. The experiment is performed in a 2.5 m depth towing tank at the Memorial University of Newfoundland. The setup is scaled to 1 : 80 to represent a 200 m ocean depth. A high-speed camera acquires the mooring line velocity and line top-end motions. A programmable linear motor, equipped with both force and position sensors, is employed to excite the mooring line horizontally in a controlled manner. A load cell is installed with the mooring line to measure axial tension. A pre-tension is applied to the line to ensure it is in the desired initial state before sinusoidal motions are imposed. The amplitude and period of these oscillations are analyzed to assess the energy dissipation performance of the semi-taut mooring configuration. This is done using the indicator diagram approach, which provides a comprehensive overview of the energy loss within the system. Post-processing techniques are applied to the captured images to extract the velocity of the mooring line, which is important for evaluating the system's dynamics. The force sensors of the linear actuator measure the horizontal force acting on the system. This is compared to the horizontal force component resolved from the load cell readings to ensure accuracy in force measurements. The results of this research will provide important new experimental data that can be used to improve the efficiency and reliability of floating wind turbines through better mooring design.

Keywords: dynamic response; semi-taut; forced oscillation; mooring damping; sinusoidal motions

Presenting Author: Evans Frimpong Memorial University of Newfoundland

Presenting Author Biography: Evans Korankye Frimpong is a mechanical engineering graduate pursuing his Master’s at Memorial University of Newfoundland, Canada. With over five years of professional experience in energy and engineering, Evans has developed expertise in condition monitoring, feasibility assessment, troubleshooting, data analysis, and technical reporting. His career spans roles at Genser Energy in Ghana, where he led reliability-centered maintenance strategies for a cumulative 150MW single-cycle gas turbine power plant. At Memorial University of Newfoundland, he is a Graduate Research Assistant investigating mooring line dynamics for floating wind turbines.

Evans’ technical proficiency is complemented by his leadership experience, which includes supervising engineering teams, driving cost reduction initiatives, and supporting the development of hybrid power systems for mining clients. His contributions to the energy sector have been recognized with several scholarships, including the prestigious School of Graduate Studies Scholarship at Memorial University. A passionate advocate for sustainability, Evans has also contributed to the decarbonization strategies of companies in West Africa.

Fluent in English, Twi, and a beginner in French, Evans is dedicated to continuous academic and professional development. His interests include table tennis, badminton, reading, and hiking, and he actively volunteers with organizations like the Canadian Institute of Mining, Metallurgy and Petroleum (CIM), Sponsors for Educational Opportunities (SEO Africa), and Rotary International.

Evans can be reached at ekfrimpong@mun.ca or via LinkedIn at www.linkedin.com/in/ekfrimpong.