Today uncertainties still exist about the actual operational performance (efficiency & loads) of tidal turbine blades. A great variety of designs is seen with different design approaches building on experience and guidelines often ‘borrowed’ from the constructors of wind turbines.
With the vastly differing properties of air and water (e.g. density, acoustic propagation) and site to site variations of environmental conditions, it is obvious that other design choices will have to be made. Much has to be learned on these aspects by the involved companies in order to reliably exploit the full potential of marine currents.
Around the world Naval Architects are using the results of model tests on systematic ship propeller series developed through joint efforts of the maritime industry. It seems valuable to follow a similar course in the development of the rotors of tidal turbines and design and test a range of horizontal tidal turbine rotor blades and include some of the most important issues related.
RESEARCH FOCUS & OBJECTIVES
Being able to accurately predict the performance of the blades of tidal turbines is a first requirement for the development of any solid and reliable tidal turbine business case. Tidal turbines will have to generate energy from a spectrum of unavoidable operating conditions as a result of tidal flow turbulence, the influence of waves and the water depth. Next to that they operate in designed conditions as a result of positioning the devices in arrays.
All of the above introduce well known issues affecting the total turbine performance.
- Rotor performance prediction
- Flow measurements
- Loads & Reliability
- Cavitation & noise
Common to all is the need for the prediction and understanding of the flow around the turbine. The following paragraphs detail the objectives and scope of work of potential research projects related to these issues and building the knowledge on the overall performance prediction of Tidal Turbine. The final choice of subjects for study is seen as the outcome of the discussion of this paper, possibly leading to a selection and order of execution of subjects or change of scope around the various issues.