Wells Turbine

A Wells turbine is a low-pressure air turbine that rotates continuously in one direction regardless of the direction of airflow through it, a property achieved through blades with symmetrical airfoils positioned in the plane of rotation, perpendicular to the airflow. It was engineered specifically for oscillating water column wave power systems, in which a rising and falling water surface inside an air-compression chamber creates alternating, bidirectional air currents; the Wells turbine eliminates the need for expensive and complex check-valve systems to rectify that alternating airflow. It operates with lower efficiency than conventional turbines using constant directional flow, ranging between 0.4 and 0.7, partly due to the symmetric airfoil own drag and stalling at high angles of attack. The turbine was developed by Professor Alan Arthur Wells at Queen's University Belfast during the late 1970s.