Experimentally Calculate Wind Turbine Torque

[mstrdnkn]

Dear All,

I'm in a bit of a pickle. I have recently booked out the local wind tunnel in order to run some simulations on three home made model wind turbines. I am aware of how to theoretically calculate the available power (0.5*p*A*V^3) and that P=Tw (Torque * Angular Velocity).

Angular velocity can be measured easily enough by recording the revolutions however i have no idea how to calculate or measure the torque?

Any help would be greatly appreciated. I can post a photo of my apparatus set up if needs be.

Cheers,

Chris!

 

[A.T.]

I can post a photo of my apparatus set up if needs be.

That would be helpful, because there are many ways how torque could be measured. The problem is that if you have already build them without planing for the torque measurement, it is hard to say what is the simplest way to adapt your design.

 

[mstrdnkn]

Sure thing, give me two minutes to upload a sketch. Yeah, we went ahead and built them without planning for torque measurement. Bit of a mistake.

 

[mstrdnkn]

http://twitpic.com/8ztc8x < Image of set up there. Effectively all that was manufactured was a turbine rotor with a bearing hub that freely rotates on a stand.

All Dimensions will be known, and after the experiment the angular velocity and windspeeds will have been recorded. If i can achieve a value for Torque i can calculate power output and thus find the Cp value.