Building a Wind Generator with a DC Motor

[wright3400]

Hi everyone. This is my first time trying this. So please be gentle. My question is to do with a dc motor. I want to build a wind generator and I am trying to figure out what size motor to start with and try to size the blades to get the best out of it. I know that their is a lot of other questions, but I can at least get started. Thanks

 

[russ_watters]

Welcome to PF!

How much power do you want to generate? Have you looked at commercially available wind turbines to see how much power goes with what size blades?

 

[Unrest]

out what size motor to start with and try to size the blades to get the best out of it. I know that their is a lot of other questions, but I can at least get started. Thanks

At the bottom of this section is a formula for power as a function of wind speed and turbine area. Just guess the 'power coefficient' and match that result to the motor power.
http://en.wikipedia.org/wiki/Betz'_law#Betz.27_law_and_coefficient_of_performance

There are many levels of difficulty in designing the blade shapes depending on how much you want to optimize it. You could use some ideal calculations (perhaps see 'momentum equation' for fluids), empricial data tables or CFD modelling.