Ingenieur Vol 68 Oct-Dec 2016 | Page 28

COVER FEATURE INGENIEUR Cross Axis Wind Turbine: Crossing into the Future By Assoc. Prof. Dr Chong Wen Tong Department of Mechanical Engineering University of Malaya The Cross Axis Wind Turbine is a complementary design to push the limits of wind turbine technology. S ituations such as low wind speed, high turbulence and frequent wind-direction changes can reduce the performance of horizontal axis wind turbines (HAWTs). Certain vertical axis wind turbine (VAWT) designs have the ability to operate well in these harsh operating conditions but they generally possess low power coefficients. In order to tackle the abovementioned problems, a novel cross axis wind turbine (CAWT) has been conceptualised to extract wind energy from both the horizontal and vertical directions of the on-coming winds to maximise the generation of wind energy. The CAWT consists of three vertical blades and six horizontal blades arranged in a cross axis orientation. Initial testing showed that the maximum rotations per minute (RPM) generated by the CAWT is 166% higher than the VAWT under the same experimental conditions together with improved starting behaviour. Computational fluid dynamics (CFD) analysis was done to illustrate the flow field of the deflected and channeled air stream by the omni-directional shroud. The air streams deflected upwards by the guide vane interact with the horizontal blades. The CAWT is applicable in a wide variety of locations, creating significant opportunities for the use of wind energy devices and therefore alleviating dependency on fossil fuels. A wind turbine is a device that converts energy from the wind into electrical power. There are basically two types of wind turbine; the horizontal 6 26 VOL - DECEMBER 2016 VOL68 55OCTOBER JUNE 2013