Abstract: This paper presents a direct comparison of four methods of predicting cross-flow (vertical-axis) tidal stream turbine behaviour. A number of prediction methods are available, and for developers of crossflow turbines it is not always clear, given their requirements, which method is most appropriate.
We compare the four most applicable methods of predicting cross-flow turbine behaviour: the blade element momentum model, the discrete vortex model, a combined boundary element/finite-volume vortex model, and Reynolds-averaged Navier-Stokes simulations. In the present work all of the methods are implemented in two dimensions in an unbounded flow.
A comparison of the performance of these methods is based primarily on predictions of blade forces on an isolated turbine of 2.5m diameter, with three blades of 0.2m chord and NACA 0024 section.
