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Compliant Coatings for Tidal Turbine Blades

  • Supervisors: Dr Ignazio Maria Viola (University of Edinburgh), Dr Maria Kashtalyan (University of Aberdeen), Prof Alistair Borthwick (University of Edinburgh), Dr Parshant Valluri (University of Edinburgh)
  • Sponsoring Company: International Paint Ltd
  • PhD Student: Thomas Jozsa

 The project aims to provide proof of concept that well-designed compliant coatings can allow drag reduction and underpin future commercial exploitation for the tidal energy industry.

One of the key challenges of tidal energy is the high cost of energy. The current project aims at improving the fluid dynamic efficiency of tidal turbine blades in order to allow a reduction of the energy cost. In particular, the drag of tidal turbine blades is proportional to the power extractable from the tidal stream and, therefore, a drag reduction would increase the capacity factor of tidal turbines and decrease the cost of energy. For a typical tidal turbine blade, the viscous forces are small compared inertial forces, the flow fluctuations are large compared to the average flow speed and the friction drag significantly contributes to the total drag. Recent findings (discussed in the following) suggest that in these flow conditions compliant walls can allow a friction drag reduction greater than 10%. Therefore, developing this flow control mechanism for the tidal energy industry can lead to a significant increase of energy efficiency. The use of compliant walls is extremely promising for a number of reasons: the potential drag reduction increases with the level of turbulence of the boundary layer; it has the additional effect of suppressing vibrations and flow-induced noise; it is a passive flow control means and therefore it is resilient to the hostile marine environment.