Session: Model Testing-1

Paper Number: 164499

164499 - Dynamic Response of FOWT Power Cables in Shallow Water 

Abstract: 

The integration of floating offshore wind technology (FOWT) is pivotal for the global energy transition, yet it presents significant technical challenges, particularly regarding the dynamic behavior and fatigue assessment of power cables in shallow water environments. This study examines the dynamic response to waves, vessel motions, and current-induced vibration (VIV) excitations for the fatigue assessment of power cables in FOWT systems, addressing the critical need for enhanced engineering methods and numerical tools to optimize design and system robustness.

Conducted by Océanide in collaboration with TechnipFMC, the project investigates the dynamic behavior of power cables subjected to harsh environmental conditions in relatively shallow waters. By employing both experimental and numerical approaches, the study will validate and refine existing fatigue estimation methods and cable design practices.

Key aspects of the study will include:

1. Experimental Setup and Testing: An extensive experimental database was established using physical models of power cables tested in the 'South France - Ocean Basin.' The tests simulated various environmental conditions, including waves, currents, and imposed motions at the cable top head.

2. Numerical Modeling and Benchmarking: Experimental data were used to benchmark and calibrate numerical tools, such as Orcaflex and Shear7, to accurately assess mechanical responses due to waves, vessel, and VIV excitations, as well as the fatigue life of power cables under operational and extreme conditions.

3. Fatigue Assessment: The study will challenge the commonly used direct summation method for fatigue estimation by comparing it with more comprehensive calculations using calibrated numerical models. This approach aims to reduce design conservatism and optimize system costs.

The study's outcomes will provide valuable insights into the dynamic behavior of power cables in shallow water environments and offer recommendations for improved numerical modeling and fatigue assessment methodologies. These findings are expected to contribute to the optimization of FOWT system designs, enhancing their robustness and longevity.

This paper will present the followings:

-          Experimental setup and setting,

-          Numerical modeling and benchmarking using Orcaflex and Shear7 tools to conduct VIV FD analysis under uniform current to validate the simplified approach of software as Shear7 for this type of riser or power cable configuration.

The remaining aspects of the study including coupling analysis and fatigue assessment are currently being developed using VIVANA-TD software.

Presenting Author: Claire Saunier Technip FMC

Presenting Author Biography: Claire Saunier, Engineer graduated from Polytech'Marseille. Specialized in dynamic analyses of risers and power cables, with over 20 years of experience in verifying the integrity of subsea structures under extreme and operating conditions, including VIV phenomena.

Authors:

Claire Saunier Technip FMC
Alex Mendes Technip FMC
Benjamin Rousse Océanide
Vincent Lafon Océanide