A Quieter and More Efficient Solution to Harnessing Wind Energy?
Numerical and experimental results obtained from testing a new generation wind turbine indicate its ability to produce greater power output when compared to conventional horizontal axis wind turbines (HAWTs). With a three-dimensional streamlined geometry, the AXTRA turbine can produce up to three times more torque than a HAWT with the same rotor diameter. The turbine blades are sloped 45? downwind to the axis of rotation, giving an effective increase in flow contact area and making use of the additional components of velocity not present in air flowing around conventional propeller blades. Results have been obtained from experimental comparisons between 870mm diameter AXTRA and HAWT turbines and confirmed by computational fluid dynamical analysis of the flow patterns and loads on the blades. The AXTRA turbine provides new potential, particularly in the smaller end of the wind market (<100kW) where variable pitch blades are not economical and the average wind speed reaches 10m/s.By Jenny Rollo and Peter Rollo, the University of Sydney, Australia
