Darrieus wind turbine

The Darrieus wind turbine is a special kind of vertical-axis wind turbine used to make electricity from the power of the wind energy. Unlike many turbines with big blades that spin around a horizontal axis, a Darrieus turbine has curved blades arranged in a vertical shape. These curved blades, called aerofoil blades, spin around a central shaft.

Because of their unique curved shape, these blades are mostly pulled by the wind rather than pushed, which helps them spin smoothly. This design was invented by Georges Jean Marie Darrieus, a clever French aeronautical engineer, who applied for a patent for this idea on October 1, 1926.

Even though Darrieus turbines are interesting and useful for producing clean energy, they can be tricky to protect from very strong winds and sometimes need help to start spinning on their own.

Method of operation

The Darrieus wind turbine has symmetrical blades. These blades work no matter which way the wind blows. Unlike regular wind turbines, it does not need to turn to face the wind. When it spins, the blades move in a circle. This motion creates force that helps the turbine keep rotating.

One challenge with this design is that the force changes as the blades spin. This causes a pulsing power output. The turbine also needs to be already spinning to generate power, so it is not self-starting. The blades are often curved into an "egg-beater" shape. This helps them stay strong without heavy supports.

Giromills

Darrieus's 1927 patent showed many ways to arrange vertical airfoils. One common type is the H-rotor, also called the Giromill or H-bar design. This design uses straight vertical blades linked to the central tower with horizontal supports. A company in Shanghai named MUCE uses this design.

Cycloturbines

A Cycloturbine is a special kind of wind turbine. Each blade can spin around its own vertical axis. This helps the blades stay at the best angle to catch the wind. It helps the turbine make steady power. It can also start spinning on its own by angling one blade to catch the wind like a sail.

Auto-Cycloturbines take this idea further. Their blades automatically adjust their angle without any sensors or computers. They use the wind's force to find the right position. This makes the turbine simpler but still needs careful design to work well.

Helical blades

The blades of a Darrieus turbine can be shaped into a spiral, like a helix, to help the turbine turn smoothly. This design was first created by Ulrich Stampa in 1979 and later suggested by A. Gorlov in 1995. This special shape makes sure the turbine spins evenly, which helps it work better without shaking too much.

This design is used by several companies such as Turby, Urban Green Energy, Enessere, Aerotecture, and Quiet Revolution for their wind turbines.

Active lift turbine

The wind moving past a Darrieus turbine creates a force on its blades. This force has two parts: one that helps the turbine turn and another that pushes or pulls on the arm as it moves.

To use this force better, a crank rod system can be added. This system turns the pushing and pulling into more energy for the turbine, helping it work better.