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By: - 20th October 2005 at 15:18 Permalink - Edited 1st January 1970 at 01:00
Canards can place the CG slightly forward of the wing center of lift. This allows the canard to generate up force and can reduce the size of wing. Think of a canard as a biplane with one wing in front of the other.
By: - 20th October 2005 at 16:06 Permalink - Edited 1st January 1970 at 01:00
Are you talkinga about center of lift or center of gravity? Center of gravity is affected by more than just the geometry of the lifting surfaces.
By: - 20th October 2005 at 21:02 Permalink - Edited 1st January 1970 at 01:00
well, regardless of the shape/geometry of wing/lifting surfaces, I know how to work out the Mean Aerodynamics Chord or centre of lift etc.
What I don't know is when I have a canard (or smaller "wing") in front of the wing rather at the back, how is that affecting everything and how it is shifting everything forward and where, I'd love some help or link to any articles or diagrams etc.
thanks
By: - 20th October 2005 at 23:18 Permalink - Edited 1st January 1970 at 01:00
The greatest aircraft designer of all time (IMO) Kelly Johnson once said, "canards belong on someone else's airplane." By the way, I don't think the center of gravity is affected by where the pitch control surfaces are located. Center of gravity is where there is the same amount of weight forward and aft of a given point.
By: - 21st October 2005 at 00:04 Permalink - Edited 1st January 1970 at 01:00
The canards will pull the CP to the front, so for longitudinal stability, you will need more drag in the rear to balance that out. I would imagine the delta wing already does this for you.
Locating CG shouldn't be difficult once you calculate the lift vectors of the delta and the canard. Make sure that the drag vectors of the canard and delta add up to a resultant which is to the rear of the CG.
For model planes without the advantage of a flight control software, I think it would be better to leave the canards fixed (without movable parts)
That comes from a non aero guy, so take it for what it is.
Posts: 245
By: lovemigs - 20th October 2005 at 10:00
Hi all,
I've designed and built a lot of conventional radio controlled aircraft few years ago, and always knew how to calculate the position of the centre of gravity, as it was very straight forward.
Now I'm thinking of getting back into Radio Control and would like to build a cool delta canard, being the Eurofighter, Rafale, JAS-39 Grippen or MIG-1.44 etc.
My problem being I have no idea how to calculate and where to position centre of gravity on these type of aircraft and or how to couple the canards to the rest of the controls.
If any of you guys knows about this or have any usefull links with information or diagrams regarding above, would most certainly be greatly appreciated.
Thanks in advance if anyone can help.
Regards LoveMigs