Introduction

The Counter-Rotating Marine Turbine (CoRMaT) is neutrally buoyant, and flies in the tidal current, remaining parallel to the direction of flow at all states of the tide. The turbine is tethered to the seabed by a tensioned mooring system.
The purpose of the project is to investigate a range of practical mooring options, and to produce a best practice flexible mooring design. An important consideration is the station-keeping of the turbine in varying flow velocities and directions.
The mooring is tensioned by buoyancy or lift forces at the top of the mooring system. A major part of the project is consideration of how these forces can be generated, and how this will influence the behaviour of the system. Options considered include: a Buoy, providing static buoyancy forces; or a Hydrofoil, providing dynamic lift forces.
Technical aspects of the Project included: fluid dynamics of submerged objects, calculation of static and dynamic loads throughout the system, and structural design of system components.

Objective

The Project objective was to design a flexible mooring arrangement for the Counter-Rotating Marine Turbine (CoRMaT).

Key Requirements

The key requirements for the mooring arrangements were as follows:
  • Station-keeping
  • Minimizing excursion & footprint
  • Stability in turbulent current
  • Cost effectiveness
  • Acknowledgements

    We are grateful to the following, whose assistance helped in the successful completion of this project:
  • Nautricity (Industry Sponsor)
  • Dr Andrew Grant (Academic Supervisor)
  • Thomas Nevalainen (CFD Analysis)