Rolling moment of a model aircraft in a wind tunnel

[Daveami]

Hello,

I am designing a rig to measure the rolling moment of a model aircraft. The rig will have a settable yaw, pitch and roll, but only the rolling moment is to be measured. The model aircraft will be similar to an Airfix model. Approx dimensions: L221 x W152. I was just wondering if anyone has done something similar and what range of rolling moments (Nm) they got. This data would be used as an approximation for calibrating the sensitivity of the rig. Alternatively if anyone knows of a reliable method to calculate an approximate moment this would be of great help. I will be testing the rig at up to 20m/s wind flows.

Any help or guidance is much appreciated!

Regards

Dave

 

[RandomGuy88]

If you know what the max CL of your wing will be you can calculate the maximum moment by assuming both wings are at max CL but in opposite direction. This would give you an upper bound, and at least might be a decent starting point.

 

[Daveami]

Thanks for the reply,

I have looked at CL with respect to the moment as well as working out the dynamic wind pressure of the tunnel and multiplying this with the area of the wing and a drag co-efficient. Just wondering how well it will relate to practice measurements.

Thanks for your help!

Dave