A large-scale model experimental study of tidal turbines in uniform steady flow

• Main Author: Atcheson, Mairéad
• Published: Queen's University Belfast 2013
• Subjects: 621.312134
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.602411

Similar to wind turbines, it is planned that tidal energy converters (TECs) will be deployed in arrays. However, before industry can progress to this stage, more information is required on the optimum spacing between tidal turbines. Experimental studies were carried out to understand how a single TEC interacts with its surrounding environment, with a view to informing device developers on the spacing requirements. The availability of two turbine models also permitted tests to be conducted assessing the performance of a tidal turbine in the wake of another. A new large-scale towing test facility was established at Montgomery Lough. As a simplification of the marine environment, the lake provided in principle the steady, uniform flow conditions required to quantify and understand the wake produced by a tidal device. A 16m long x 6m wide twin-hull catamaran was constructed for the test programme. This doubled as a towing rig and instrument measurement platform, providing a fixed frame of reference for measurements in the wake of the turbine. Tests carried out documented the performance of the single TEC models tested and mapped the downstream wake generated. Tests were also completed to investigate the influence of the wake of a TEC, on the performance of a second device, at varying separation distances. The large-scale experiments also provided a test bed to compare the ability of different velocity measurement instruments to measures the wake of a tidal turbine. Three different acoustic instruments were used, two varieties of acoustic Doppler current profilers and an acoustic Doppler velocimeter