**How do you calculate the diameter of the shaft of a wind turbine?**

I have the length of the blade of 50 cm. I found out the power that is going to be generated by the blade by the equation P=p(density) * A * v^3 * Cp

The Cp was chosen to be 0.4

now it comes to the shaft diameter. How do I calculate the shaft diameter on this basis?

**Best answer:**

*Answer by Jackson*

Is this for a Horizontal Axis Wind Turbine or for a Vertical Axis Wind Turbine?

The diameter would be the diameter of the circular area that is cut by the blades.

If you were to put a small light on the end of one blade, and then watch the **wind turbine** at night --- you would observe a lighted circle. It is the diameter of that circle.

These links below will offer more detail:

http://en.wikipedia.org/wiki/Wind_turbines

http://science.howstuffworks.com/environmental/green-science/wind-power4.htm

http://www.ehow.com/how_5920721_size-wind-turbine.html

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