Marine current turbines (MCTs), such as the 'Seaow' and 'Seagen' devices (Fraenkel, 2007) represent an important technology for harnessing marine renewable energy. The hydrodynamic behaviour of such devices includes complex interactions between the turbine and ocean turbulence, as well as turbine wakes if sited in arrays. These should be accounted for in performance assessments. Traditionally, blade element momentum (BEM) models have been used to assess turbine performance, either in isolation (Batten et al., 2007) or array configuration (Turnock et al., 2011), the later study combining this approach with computational flud dynamics (CFD) simulations to model turbine wakes. Recently however, modelling the unsteady performance of turbines using viscous CFD has become more popular for the assessment of transient performance and blade fatigue loads (Faudot and Dahlhaug, 2011; Lawson et al., 2011) which are important for determining operational lifecycles. This is possible through the use of unsteady CFD techniques such as unsteady Reynolds-averaged Navier Stokes (URANS) solvers and dynamic meshing. This paper presents the initial findings of a study carried out using the CFD library OpenFOAM to predict the performance of a single turbine in a test tunnel environment, with comparison to the experiments of Bahaj et al. (2007). The main aim is to establish the use of dynamic meshing for conducting unsteady CFD simulations of turbomachines, with possible other applications including ship hull-propeller-rudder interaction.
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