A curved tip, or winglet, for a wind turbine blade, based on the shape of condor wings
Khashayar Rahnamaybahambary
A design modification inspired by the wings of the Andean condor could increase the energy generated by wind turbines.
Various bird species have upturned tips on the end of their wings, which help maximise lift. Similar features, known as winglets, are commonly used on aircraft wings, but haven’t been tested on the giant turbine blades used in power generation.
Khashayar Rahnamaybahambary at the University of Alberta in Canada says gathering experimental data on winglet-equipped wind turbines is very difficult because of their size.
His team designed winglets based on the world’s heaviest flying bird, the Andean condor, which can cover vast distances despite weighing as much as 15 kilograms.
A computer simulation of air flow through a turbine found that these winglets would reduce drag and enhance efficiency by 10 per cent on average.
“Another perspective is that winglets enable turbines to capture more wind energy by minimising losses [resistance],” says Rahnamaybahambary.
Winglets can be retrofitted after turbine production and installed “somewhat like a sock” slipped onto the end of the blade, he says. The researchers are developing an experimental set-up to test a model of the winglet in a wind turbine.
Peter Majewski, who has recently retired from the University of South Australia, says the findings of the study make sense from an engineering and aerodynamic perspective, but retrofitting existing wind turbines may be impractical because of downtime and cost.
But for new turbine blades, the addition of winglets in the production process could lead to significant performance improvements, he says.
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