Transverse Horizontal Axis Water Turbine
The Transverse Horizontal Axis Water Turbine was conceived by Prof. Guy Houlsby, Prof. Martin Oldfield and Dr. Malcolm McCulloch in the Department of Engineering Science at Oxford. Experimental tests of scale models have shown that the device is capable of producing power with an efficiency significantly greater than the Lanchester-Betz limit. This is because the device can be scaled across a channel and utilise blockage effects to extract a greater amount of energy from the flow than a more conventional horizontal axis device.
The patent pending truss design uses the turbine blades as structural members and allows the device to be stretched laterally across a tidal channel. Structural analyses of the device, performed using Finite Element Analysis software, has shown that the truss configuration reduces the stresses significantly in a multi-bay rotor so that very long devices are feasible. The simple design and scalability of the device mean that fewer foundations, bearings seals and generators would be required for a given area of energy capture when compared to a more conventional horizontal axis turbine.