The interesting world of VAWTs
I was curious about the type of wind turbines that do not need to face into the wind. So I googled
around to learn they are called Vertical Axis Wind Turbines (or VAWTs). But that is not all there is to it. There are a handful of different designs built around two basic concepts: drag and lift. And as you can guess, these are not as efficient as the more popular Horizontal Axis Wind Turbines (HAWTs) found on most wind farms.
The beauty of the VAWT is their simplicity: Just a special shape the wind will rotate and, if connected to a generator, it could be used to produce energy too. But its power-generation capability is somehow smaller (if you consider the frontal area it presents to the wind) than the propeller rotors of the HAWTs.
On the other hand, some of the designs, have been created quite simple so they can be built repurposing other objects. For example, the basic Savonius rotor can be built by joining two halves of an oil barrel in an S-shape configuration. Any other cylindrical, metal or plastic, can be used too. And while this rotor is not very efficient, it can be built very easily and cheaply.
A more smooth motion can be obtained with twisted profiles, like the one in the picture on the right. And these can also be quieter. But to get more power from the wind, the Darrieus type of rotor is preferred. This rotor is based on lift instead of on drag, and it is made of several aerofoil blades that sit vertically (or forming a helix in Gorlov rotors). But the main problem with this latter type of rotors is they do not start rotating by themselves even in high winds. So it is quite common to have a small Savonius rotor inside to help it autostart rotating.
A not so studied nor mentioned is the Ugrinsky rotor, which seems to double the power generation capacity of the Savonius rotor.
Luckily, you can find 3D models for any of these types of rotors and 3D print them in case you want to play with them.
The beauty of the VAWT is their simplicity: Just a special shape the wind will rotate and, if connected to a generator, it could be used to produce energy too. But its power-generation capability is somehow smaller (if you consider the frontal area it presents to the wind) than the propeller rotors of the HAWTs.
On the other hand, some of the designs, have been created quite simple so they can be built repurposing other objects. For example, the basic Savonius rotor can be built by joining two halves of an oil barrel in an S-shape configuration. Any other cylindrical, metal or plastic, can be used too. And while this rotor is not very efficient, it can be built very easily and cheaply.
A more smooth motion can be obtained with twisted profiles, like the one in the picture on the right. And these can also be quieter. But to get more power from the wind, the Darrieus type of rotor is preferred. This rotor is based on lift instead of on drag, and it is made of several aerofoil blades that sit vertically (or forming a helix in Gorlov rotors). But the main problem with this latter type of rotors is they do not start rotating by themselves even in high winds. So it is quite common to have a small Savonius rotor inside to help it autostart rotating.
A not so studied nor mentioned is the Ugrinsky rotor, which seems to double the power generation capacity of the Savonius rotor.
Luckily, you can find 3D models for any of these types of rotors and 3D print them in case you want to play with them.
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