Canards - Location, design, angle, and size?

In reply to Gimp (Forum Supporter) :

Ooooh yum.  Love it sir.  Carry on.

I am in agreement with Sleepyhead on the options to test and the general direction for the partial area end plate shape. On the endplate shape, I might go with a longer triangle and lower the trailing edge to tune area. The trough at the wheel opening/splitter/endplate is just a stagnation pressure area. You dont want the vortex spooled up from the endplate to impact the canard too much.

I would start your canard shape at the full size you had mocked up the first time around and see what that leaves for the endplate.

The dual voticies generated will both draw the front underbody flow, butbthe lower one will likely get pulled into the rear underbody. The both will have the effect of pulling air downward toward the rear of the car for more spoiler pressure/downforce.

Thank you both!

The full size canard came in at 86 sq. in, so that doesn't leave much for an endplate. I can make it about 2 inches shorter and it comes out to 70 sq. in. I may start there and see what a 30 sq. in. endplate looks like. 

Happy New Year!!

Just as a point of interest. AJ. Hartman just did a wind tunnel test on ducks he makes for Mustangs. And they are placed higher (starting from the bottom of the head lights /upper front facia). I bring this up because they contributed to rear down force. While helping overall aero balance. Would moving the second version higher help push flow to the rear spoiler?

In reply to BarryNorman :

It is all veryy car specific. This particular build is a rolling test bed, so anything is possible. Votricies are usually very low pressure and vortex impact on the spoiler would result in less rear downforce.

Thoughts on modifying the end plate like this?

Both get the end plate under 30 sq. in. and keep full height and length. 

that could work. it will try to send the vortex lower on the car and interfere less with the dive plane vortex

This thread is all extremely relebant to my interests as I'm starting to build my splitter for the MR2 and I'd love to to some canards as well. I don't have sq/in restrictions to deal with, though, just max dimensions (6" splitter, canards inside splitter plan view). 

Paul I'm really interested in your materials and fastening solutions. Please keep us updated on what you're using and how you're attaching it

Been chipping away at things.  The rough aluminum canards I made are now body worked, painted, polished, and ready to become a mold.

As far as attaching, I'm still scheming on that, but should have some ideas out here soon.

Oh, here they are before body work (and final placement).

Shiny

Keep it up

Getting closer. 

Hopefully this isn't a "too late, should have thought of that," but I was talking about this project with a friend, and he was wondering if it's an issue that the canards meets up with the flare, and if I should instead set them a little more forward so they don't touch, allowing a place for air captured below the canard by the air damn to escape.

Here you can see the canard butts up against the flare, creating a trapped space beneath it.  I have room to move the whole canard forward an inch or two when mounting, which would allow a vertical escape path for air.

What say you all?  Over thinking it for an autocross car?

I think you are missreading the Size rules.  Or maybe I am.

Section 17.2 says:

The splitter and canards may have endplates. The endplates may connect the splitter and the canard. The splitter and canard endplate total surface area is limited to 100 sq. in. (645.2 cm2) for each side. Canards are allowed and may extend a maximum of 6” (15.24 cm) forward of front bodywork/fascia as viewed from above. No portion of the canard may extend past the widest part of the front bodywork/fascia as viewed from above. Canard area will be measured in the same manner as wings using Section 12.10. Canard area may not exceed 1.2 sq. ft. (1114.8 cm²).

100sq-in is the area of the endplates.  It looks like the actual canards when measured as a wing can be 1.2 sq-ft EACH (172.8").  A canard is not defined as a "Pair" of canard elements on each side of the car, but your prepared rules allow "Canards".   

To be safe each Canard should probably be .6 sq-ft or 86sq-inches..   But..  I'd try to argue that the rules limit the size of a Canard and allow 1 per side.  The tapper is a bummer though as your absolute area becomes limited because the width is the widest part of the front.  

Per section 12:

canard A three-dimensional (3D) attachment to the front fascia with air passing over the top and bottom surfaces, which is intended to provide aerodynamic downforce to the front of the vehicle. Unlike a wing, one (1) edge must be flush to the attachment surface. No portion of a canard may extend vertically above the front fascia/bodywork.

wing area computation The area of a wing element shall be computed by multiplying the maximum chord (straight line distance from leading edge to trailing edge) by the maximum span (width). Curvature 2023 SCCA® National Solo® Rules — 71 12. Definitions of the element (camber) and angle of attack when mounted on the vehicle will not affect the area measurement. The area for multipleelement wings will be the sum of the individual areas of each of the elements.

In reply to nocones :

So, if I understand what you're saying, you are suggesting that my "combined" total of the canard and the end plate is where I got confused.  Instead, you are suggesting I can have splitter endplate with a total surface up to 100 sq. in. and independent of that I can have a canard that is 1.2 sq. ft. (172.8 sq. in.)?

In other words, I could go bigger on the canard (probably won't for now), but I may not have to trim down my endplates to stay legal?

In reply to Gimp (Forum Supporter) :

Yes.  The rules have 2 distinct elements with area limits. 

The canard itself (horizontal portion) is limited to 1.2 sq-ft.  

The Endplate (vertical portion) is limited to a combined (canard+splitter) 100sq-in per side. 

The only remaining question is if the limit is 1.2 sqft per defined Canard which by definition you have 2 or 1.2 sqft of total canard area on the car.   

As a total aside I'm not sure that the rules as written prevent this..

forgive the terribad sketch. 

Since the rules fail to state the canard has to be above the splitter there is nothing preventing it from just being a short wing.  It is defined as allowing air above and below to function as a wing.  

So why not narrow your splitter and attach your canard outboard of it's endplate.  You would then mount the canard very low on the car because..  well it's a wing.  But you would only ever call it a canard and refer to it as such.   Have some portion of one edge actually attach to bodywork so it would be a "Canard".   

In reply to nocones :

Honesty, that's a great sketch!

As far as the splitter changes, I'm intrigued.  Not sure that happens this year, but with some more research this could get very interesting.