The paper deals with the preliminary design of the air turbine of Wells type for the prototype OWC wave power plant planned to be installed in the island of Pico, in the Azores. Several different configurations are considered, namely the monoplane and, the biplane turbines, including a modified version of the biplane rotor with staggered blades. Design methods based on two-dimensional and quasi-three-dimensional flow models are used to compare the geometry and performance of the turbines.
The paper deals with the preliminary design of the air turbine for the prototype OWC wave power plant planned to be installed in the island of Pico (population about 15 thousand), in the Azores. The power plant will stand on the sea bottom, adjacent to the rocky coastline. The horizontal axis air turbine, driving an asynchronous generator, will be installed onshore and connected to the OWC pneumatic chamber by a duct. The input data for the turbine design was provided by testing a 1/35-scale model of the power plant in an irregular wave tank, as well as by wave measurements on site. The air turbine to be designed is of Wells type. This is a self-rectifying axial-flow turbine which was invented in the mid-seventies by Dr A.A. Wells for wave power utilization. The original version of the Wells turbine has a rotor with a set of symmetrical airfoil blades, fixed to a hub, with their plane of symmetry normal to the axis of rotation. Versions of the Wells turbine have been studied with and without stationary guide vanes.
