andy B wrote:indranilroy wrote:
Hi Andy, I am no aero engineer either
![Smile :)](./images/smilies/smile.gif)
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A positive AOA of the canard has a pitch-up effect of the nose. In this case the leading edge is higher than the trailing edge.
Negative AoA is the opposite.
However, in that particular picture, the canard seems to be working as an air brake (since the drag grows with magnitude of AoA). As an air brake on the ground, you would like to push the plane to the ground for better friction (by increasing normal force like in an F1 car). So you would like to push the nose down, hence negative AoA of canard.
Okies thanks for that reply completely understand I was a bit confused about my understanding of what position would the said control surface be in when pitching up and pitching down and from your reply I can see that my understanding is right Phew!!!
Now coming to the pic saar I think that the canards are pitching up in this particular instance the reason i say this is because if you look at the canard front and rear shape they are clearly different and if the canard was pitching down you would have the straighter end part going up instead we have the front inclined part going up (hope that makes some sort of sense its a bit hard to explain with just words)
what do you think???
It definitely could be. May be the plane was not using it as a airbrake. May be the pilot was just checking the functionality. It might be that the canards are at positive AoA in this pic. My point in the discussion was that the trailing edge is not straight.
David has the opinion that
1. The canard is not swept back
2. Leading edge of canard and the wing are edge aligned
3. Trailing edge of atleast the canard swept forward (may be edge-aligned with the trailing edge of the wing)
My contentions are
1. The canard is slightly swept back
2. Leading edge of canard and the wing are not edge aligned
3. Trailing edge of the canard is actually swept back (obviously if 1 is true) and is most probably edge aligned with the trailing edge of the wing.
In addition I feel that in the C-G rendition (that David provided) the outer edge of the wing is not correct. I believe, it will be edge aligned with the outer edge of the canard. If not, I would be very dissapointed with this design in terms of RCS reduction.
We are both waiting for planform pics/videos.