A lot of research and focus is given to large horizontal wind turbines because they're able to generate so much energy individually and in large wind farms, but small wind turbines in more urban settings can still pack a punch if they're designed and positioned in a way that lets them generate the most energy. But what designs are better and where exactly on a roof is best? That's exactly what new modeling software from researchers at Murdoch University is being used to figure out.
When wind turbines are placed in cities, more than just wind speed affects their performance. Wind shear and turbulence can be different in any given spot due to the position and shape of surrounding buildings.“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,” said PhD student Amir Tabrizi.
Tabrizi is working on developing a three-dimension computational fluid dynamics model built with OpenFOAM software that will incorporate various wind environments and factor in things like height, prevailing wind directions and the effects of different building shapes. So far, he's found that rooftop and forest sites both face far more turbulence than the current design standard for small wind turbines, which is based on open space installations, equips them for.
“Ultimately we want to establish better guidelines for design and installation of urban wind turbines to maximize efficiency and guarantee safety," 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."
Having this information could lead to much more efficient urban wind energy generation.