Combined wave-current loading on tidal stream turbines

Started: July 2015
Supervisor: Spinneken, J.Piggot, M.D.
Funding: Energy Futures Lab

Description of Research

Tidal Stream Turbines (TSTs) is a new and growing technology able to harvest energy from tides and provide 'green electricity' to the end users. The design and operation of a TST has many similarities with these of a wind turbine and therefore a number of methodologies can be transferred directly from the wind energy research. However, a number of key differences exist, such as:

  • the inflow turbulence characteristics,
  • the possible occurrence of cavitation,
  • and the blocking effects due to the free-surface proximity.

In recent years, many studies have been conducted and others are still in progress concerning the inflow turbulence characteristics. Similarly, the cavitation problem has been examined in the past, through the study of marine propellers, and a wealth of information is available for the design of the rotor blades. The free surface proximity on the other hand, although it has been addressed in the past through experiments and theoretical models,  there is still much to be learnt from the free surface – near wake field interaction and how this interaction relates to the turbine performance.

In this project, we seek to investigate the interaction of the wake of a fully immersed turbine with a free-surface boundary under a combined wave and current (turbulent) loading. The approach involves the use of a high-fidelity Large Eddy Simulation (LES) algorithm to model the turbulence loading and the wake evolution as well as a fully non linear description of the free surface boundary conditions. The study aims to gain some insight on the free surface blocking effects which can be used within array scale optimisation problems.

Background

Georgios is a graduate with an M.Sc in Civil Engineering from Virginia Polytechnic Institute and State University (Virginia Tech), USA.

GEORGIOS DESKOS
Georgios DeskosPhD Candidate - Fluid Mechanics 
Department of Civil & Environmental Engineering 
Imperial College London SW7 2AZ 
g.deskos14@imperial.ac.uk