Wind turbine Project
I have a wind turbine project
I'm in the design process of Blades.
As far as I know the blade is consisting of airfoils , like 9-10 airfoils are made in differnt planes then connecting between them by Loft command
is it same airfoil along the blade ? or it can be different types of NACA airfoils shapes or profiles along the blade ? why if yes and why if not.
how about twisting ? when and where to twist the airfoil
I’d use only 2 aerofoil sections, one for the root and one for the tip of the blade. You can use guide curves if you want to control the mid sections. This should give a smooth result.
As the blade rotates, an ‘apparent wind’ will be generated (caused by the motion of the blade through the air). This will be stronger at the tip than the root. Combine this with the actual wind velocity to make a resultant vector. This will be different at the root and the tip. The angles of attack need to be set in accordance with the angle of this resultant vector.
For the root section, I’d use a high lift section with a high angle of attack (this will produce relatively high drag). Resolving the forces, most of the lift will pull the blade around and most of the drag will tend to push the whole rotor back.
For the tip, I’d use a smaller very low drag section at a shallow angle of attack. Most of the lift here will tend to push the whole rotor back. And most of the drag will resist the motion of the rotor.