Abstract
Quantifying the discrepancies introduced by different rotor modelling approaches is essential for understanding their predictive capability and limitations. This study presents numerical simulations (using ANSYS Fluent and HORSES3D[1]) of a horizontal-axis tidal turbine with 1.6 m diameter rotor under design operating conditions, where the tip speed ratio is set to be 6.03. The multi reference frame, sliding mesh and actuator line techniques are used to simulate the rotation. The predicted force coefficients and moment coefficients are validated by comparison with experimental data, which is from the Tidal Turbine Benchmarking Project conducted and funded by the UK’s EPSRC and Supergen ORE Hub [2]. It is shown that the force coefficients predicted using the sliding mesh technique are closer to the experimental data while the actuator line method predicts the bending moment coefficients more accurately. Overall, the actuator line method coupling with large eddy simulation in HORSES3D performs an encouraging accuracy for the turbine performance and demonstrates its advantage over Reynolds-averaged Navier-Stokes (RANS) equations for the downstream wake structures.