Modeling tidal turbines

Performance prediction models are valuable tools for use in the development of tidal turbines. A model that can accurately predict the performance of a device can be used to optimize the design parameters more rapidly and at a much lower cost than carrying out the design studies using scale model tests. Tidal turbine models are principally dependent on the aerodynamic models developed for wind turbines, but the use of aerodynamic models fails to take into account the differences between wind and tidal turbines, one of which is that tidal turbines operate in a fluid with a free surface. The effect of this difference in boundary conditions on the flow is considered by analysis of the change in far field pressure distribution caused by the free surface. This analysis shows that the change in the far field pressure distribution will affect the turbine power coefficient.