Operational issues surrounding the use of towing tanks for performance quantification of marine current energy converters

Towing tanks are being utilised far more frequently for the performance quantification of Marine Current Energy Converters (MCECs) due to their relatively low cost and ease of use. In this paper a number of issues are addressed that arose during a series of experimental campaigns investigating the performance of both static and dynamic MCEC models. These include the lack of ambient turbulence, carriage vibration, repeatability, carriage advance speed, vortex-induced-vibration and blockage. Results of experiments are also compared to those in circulating flumes and the relative merits of each type of facility are presented. Recommendations are that specific types of experiments such as wake measurements, power capture etc. are better suited to a specific type of facility although it is acknowledged that facility availability is often the overriding factor. It is difficult to judge previous published and ongoing work but the authors believe that many of the issues quantified in the paper through real world MCEC experimental studies are easy to overlook and could lead to less accurate experimental results. Recommendations for measurement of experimental parameters through the various stages of experimentation are given in order that future studies can be more comprehensive