Published on September 17th, 2012 | by Joshua S Hill2
Computer Modelling Could Help Boost Urban Wind Power
Researchers from Murdoch University in Western Australia are hoping to use three-dimensional modelling of urban wind flows to improve the design and efficiency of small wind turbines located in the city.
The project will be run by PhD student Amir Tabrizi — a student at the School of Engineering and Energy under the supervision of Dr Jonathan Whale, Dr Tania Urmee, and Dr Samuel Gyamf — who said the project would look at wind data from open spaces, rural areas, and urban settings to understand the differences of wind shear and turbulence.
Mr Tabrizi said this would help improve the current design standard for small wind turbines.
“The current design standard lists design turbulence intensity as 18 per cent across a range of sites, but this result is appropriate for open-site testing only. While it is very early days, our on-site testing has shown turbulence intensity of up to 24 per cent at an urban site in Port Kennedy and 30 per cent at another urban site in Melville,” Mr Tabrizi said.
“A knowledge of turbulence intensity helps predict the load on the machine, so it informs the required design strength of turbine components, including the tower and blades. We need accurate data to ensure turbines are strong enough for all conditions.”
Currently, Mr Tabrizi is working on adapting a two-dimensional model into a three-dimensional computational fluid dynamics model. The modelling will incorporate the dynamics of various wind environments, taking into account variations by height, prevailing wind directions and the effects of different building shapes.
Already, the simulations have suggested that both rooftop sites and forest sites face turbulence intensity values much greater than those believed to exist in the current design standard.
“Ultimately we want to establish better guidelines for design and installation of urban wind turbines to maximise efficiency and guarantee safety,” Mr Tabrizi said.
“For a small wind turbine, mounted on a rooftop, for instance, we need to determine what part of the roof catches the most energy, how far the turbine should be above the roofline and how far back it should be from the edge of the roof.”