EGU24-16226, updated on 09 Mar 2024
https://doi.org/10.5194/egusphere-egu24-16226
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under the Creative Commons Attribution 4.0 License.
Effect of Increased Geometric Complexity on LoadActing on Floating Offshore Wind Turbine Platforms
- 1Energy and Environment Institute, Kingston upon Hull, United Kingdom of Great Britain – England, Scotland, Wales
- 2Offshore Renewable Energy Catapult, Glasgow, United Kingdom
Renewable energy sources, including offshore wind energy, are fundamental to reducing fossil fuel
consumption and greenhouse gas emissions. Many countries are planning for a rapid and massive ex-
pansion of the offshore wind sector to meet the NetZero goals. So far, the installation of offshore wind
turbines (OWT) has been restricted to near-shore shallow water (≤ 60m). However, future expansion
of the sector will be in deep waters, away from the shore, where the wind speed is stronger and more
consistent. Monopiles, the most commonly used foundations for OWT, become uneconomical or tech-
nologically unfeasible in deep waters. Therefore, OWT supported by floating platforms is the way to go
forward. The initial platform designs and construction were based on the experience obtained from the
oil and gas industry (O&G). However, the load acting and the movement of the floating offshore wind
turbine (FOWT) platforms are vastly different from the O&G platforms. In addition to the aerodynamic
loading, these platforms are subjected to hydrodynamic loading, making platform design a complex task.
Evaluating the forces acting on these platforms, even under idealistic conditions, is challenging. Although
significant progress has been made, platform, anchor, mooring, and turbine design improvement depends
on accurate load calculation. Further, understanding hydrodynamic loading is essential to evaluate the
energy losses due to the FOWT system and, therefore, the mixing of the water column behind the struc-
ture. In this research, the effect of increased geometric complexity on load acting on a semi-submersible
platform is numerically investigated. Three unidirectional flow regimes of Reynolds number (Re) = 2900,
43000, and 200000 are investigated, using the OC4 semi-submersible platform as the reference. The OC4
semi-submersible platform was developed by the OC4-DeepCWind consortium to obtain experimental
data and validate numerical models for FOWT. The results show that the drag force acting on the plat-
form increases as the Re and number of members in the platform increases. These findings are important
in understanding the hydrodynamic loading on FOWT platforms under static conditions and designing
the platform, mooring and anchoring systems. Further, this is essential for the sustainable development
of the offshore wind energy sector.
consumption and greenhouse gas emissions. Many countries are planning for a rapid and massive ex-
pansion of the offshore wind sector to meet the NetZero goals. So far, the installation of offshore wind
turbines (OWT) has been restricted to near-shore shallow water (≤ 60m). However, future expansion
of the sector will be in deep waters, away from the shore, where the wind speed is stronger and more
consistent. Monopiles, the most commonly used foundations for OWT, become uneconomical or tech-
nologically unfeasible in deep waters. Therefore, OWT supported by floating platforms is the way to go
forward. The initial platform designs and construction were based on the experience obtained from the
oil and gas industry (O&G). However, the load acting and the movement of the floating offshore wind
turbine (FOWT) platforms are vastly different from the O&G platforms. In addition to the aerodynamic
loading, these platforms are subjected to hydrodynamic loading, making platform design a complex task.
Evaluating the forces acting on these platforms, even under idealistic conditions, is challenging. Although
significant progress has been made, platform, anchor, mooring, and turbine design improvement depends
on accurate load calculation. Further, understanding hydrodynamic loading is essential to evaluate the
energy losses due to the FOWT system and, therefore, the mixing of the water column behind the struc-
ture. In this research, the effect of increased geometric complexity on load acting on a semi-submersible
platform is numerically investigated. Three unidirectional flow regimes of Reynolds number (Re) = 2900,
43000, and 200000 are investigated, using the OC4 semi-submersible platform as the reference. The OC4
semi-submersible platform was developed by the OC4-DeepCWind consortium to obtain experimental
data and validate numerical models for FOWT. The results show that the drag force acting on the plat-
form increases as the Re and number of members in the platform increases. These findings are important
in understanding the hydrodynamic loading on FOWT platforms under static conditions and designing
the platform, mooring and anchoring systems. Further, this is essential for the sustainable development
of the offshore wind energy sector.
How to cite: Dhar, N., Dorrell, R. M., Lloyd, C. J., McLelland, S. J., and Walker, J.: Effect of Increased Geometric Complexity on LoadActing on Floating Offshore Wind Turbine Platforms, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16226, https://doi.org/10.5194/egusphere-egu24-16226, 2024.
