Canard Wings: Effective or a Drag?
By Vic Cooke
A lot of folks have shared their dislike of how canard wings look. Not that it means a darned thing, but personally, I don't find the old-style, single-element canards that offensive. Properly done, they can look kinda "bad." I agree, however, that the multi-element canard "boxes" that a lot of the nostalgia cars are using are rather ugly. No sense debating aesthetics, though, as we all have our minds made up as to what we do and don't find cool. To each his own on that.
It's the subject of "performance" that really prompts this note. A canard can and does provide downforce... but also drag. A lot of guys back in the '70s set them at such a steep angle of attack they defeated the purpose by generating as much drag as downforce! (You still think this going on today!) Canards also got stuck on cars that couldn't really benefit from the downforce enough to justify the drag.
The situation where a canard can help is where you've got ground speed up over, say, 150 mph and way more horsepower available than you can really lay down on the track. It's been this way in Top Fuel ever since canards were first tried. So what if you waste some surplus hp on drag if it permits a net gain in how much you can deliver as tractive thrust and how soon into the run you can begin compounding the net gain?
Low, side-mounted canards are compromised (in comparison to an overhead single wing) by having to be positioned ahead of the vehicle center of gravity and in disturbed air. However, when that's all the rules allow (as in Nostalgia Top Fuel), there's still high likelihood that a well-executed canard setup will deliver a net performance gain.
I think they make perfect sense in a "rules limited" situation like current Nostalgia Top Fuel.