Three-bladed wind turbine with 4-inch spherical cap nose cone

After reading about engineers at GE experimenting with nose cones to improve wind turbine efficiency, we decided to design and test our own nose cones on a KidWind Wind Turbine. One of our engineers created two different spherical-cap-shaped nose cones in a CAD program and printed them on a 3D printer. The nose cones were designed to fit onto the KidWind Wind Turbine Hub by fitting over the T-bolt and holding on with friction.

We designed a series of experiments to test the effect of the presence and shape of a nose cone under a wide range of conditions, including variations in wind speed, blade shape, and blade pitch:

Wind speed Blade shape Blade pitch
Three speed settings on a Lasko, 20-inch square fan: high, medium, and low Two rectangular blades: 1 inch × 9 inch and 3 inch × 6 inch 10°, 20°, and 30°

In the majority of our tests, the difference in energy generated with and without the nose cones was non-existent, or within the uncertainty values of the measurements. This was a disappointing, but meaningful, finding.

However, there was one set of trials that showed a significant difference when the nose cone was attached. At the highest wind speed, a load of 51 Ω, and the 3 inch × 6 inch blades at a 30° angle, the turbine produced an average of 7.0 ± 0.1 mW without the nose cone and an average of 9.16 ± 0.09 mW with the 4-inch-diameter nose cone—an increase of about 30%.

Four representative data-collection runs with and without nose cones—the top two traces represent the trials where we observed the biggest difference in power generation; the bottom two traces show no significant difference.

You and your students can do a similar experiment. If you don’t have access to a 3D printer, you can use hemispheres of expanded polystyrene from a craft store, which is what the GE engineers used for their early prototypes. If your students have experience with CAD software and access to a 3D printer, they can design their own nose cones or modify our designs, which are available for 3D printing at