This close replica of the logo/icon for Google Chrome, the world's most popular web browser, is built off of a geometric reconstruction of the logo's shape, allowing the logo to "spin" as you drag a point around its edge.
This app models the top view of the Twisted Savonius Vertical Axis Wind Turbine (VAWT). The various inputs and draggable points allow you to see how the model can trace the blades' surfaces. You can also control the twist angle, radius, and rotation - which makes the whole thing spin!
Learn more about the Twisted Savonius Modeling Project here.