Wind Turbine Blade Design
A modern wind turbine blade is designed in a shape that is similar to the wings of an airplane.
Airplane wings are very aerodynamic, able to let wind pass by at very high speeds.
Wind turbine blades have been designed in many shapes and styles throughout the evolution of wind energy technology.
The blade of a modern wind turbine is now much lighter than older wind turbines so they can accelerate quickly at lower wind speeds.
Most horizontal axis wind turbines will have two to three blades, while most vertical axis wind turbines will usually have two or more blades.
If you notice from the diagram below (a cut section of a wind turbine blade) the blade has one flat side and one more rounded side.
The wind in the picture of the blade above that has to travel around the longer, curved side, creates a lower pressure pocket while the wind below remains the same pressure, thus becoming a higher pressure than the wind above.
On the flat, higher pressure side of the blade, a lifting force is created due to the fundamental laws of air particles preferring to move from a high pressure to a lower pressure area.
This creates a force that is similar to the force that helps an airplane fly. In this case, though, the lift creates a rotational force and causes the blades to spin in hopes to create enough rotational force to power a turbine generator.
The wind turbine blade design will vary between manufacturers and types of turbines, however the theory of “lift” is consistent with every wind turbine blade design.