Canard AOA?

[tiggs]

I am going to put together a canard airplane with a flat plate canard.

What AOA should it have relative to the Clark Y main wing...

1,2,5 degrees?

Ted

[Ollie]

The decalage determines the trimmed flight speed and depends on the CG location. The more forward the CG the greater the decalage needed. The slower the trimmed flight speed the more decalage needed. It also depends on the relative area of the fore wing compared to the aft wing. With all these dependencies it is best to make either the fore wing or the aft wing incidence adjustable so that the final decalage can be arrived at by flight tests. To begin flight testing, start with a decalage angle of about 4 or 5 degrees.

No matter what the final decalage turns out to be, the angles of attack will vary with flight speed and maneuvering because AOA depends on pitch attitude. AOA is the pitch angle that the wing chord line takes relative to the direction of flight.

[DaveGherardini]

Ted, Well, ide have to agree. Why do you need to have positive AOA. The wing is going to go the direction the elevator pressure {-,+}points it at the speed. I would just make it in the upper 3's er so for a slow flyer and level for a higher speed ship. But thats just my opinion from a modelers point of view. It will fly at any of your choices asumming the cg is where you want it to. It is possible to get a particular speed say 20knots. Where the horizontial is paralell with the elevator and no hint of climbing or desending. But this usually does not stay the same through the speed range. And change the cg and it will trim different at that speed.. This is just mostly from my experiance from making planes and i would have to say that if your were to pick out a cruise speed then set the incidence for the that angle as if your were in the cockpit you would not have to push forward on the stick or pull back to maintain altitude. But for a foamy canard just build it and see how it reacts and build the next one different and you will find that it trims different. Just my 2 cents worth..i Hope i have helped a little. I have had a lot of help here at ezone and try to share my stuff to give some back.

Dave G

[tiggs]

Thanks for the input guys!
As this version is to be a slow flyer, I'll start with 3 degrees and go from there.

I think that I will go with a fixed canard and use an elevon function for now. Maybe later I'll try a moveable canard.

Ted