Abstract
The Wells trubine is one element in a chain of devices by which te oceans' wave power resource can be tapped. This paper reports a study of the performance and aerodynamics of a Wells turbine using a three-dimensional, flow solver for the Reynolds-averaged Navier-Stokes equations. Calculations have been performed for a monoplane device comprised of NACA 0015 blades under the conditions : Reynolds number 8×105, tip Mach number 0.4, hub-to-tip ratio 0.6 and tip clearance 2%. To study the effect of solidity calculations were performed for different numbers of blades. It is shown that the predicted effect of solidity on the turbine pressure drop, torque and efficiency agrees qualitatively and quantitatively with experimental data. The discrepancies can be partly explained by geometric differences between the experimental and numerical turbines. It is also shown that increasing turbine solidity increases the resistance to stall by strengthening the blade-to-blade interactions in the hub region.
