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-   -   Current state of the art for Canards? (https://www.miataturbo.net/suspension-brakes-drivetrain-49/current-state-art-canards-43596/)

Chris Swearingen 02-03-2010 10:38 PM

Current state of the art for Canards?
 
Ok, all you track aero knowledgeable people out there, lets assume for a moment that your design parameter is total area of all canards cannot exceed 172 square inches.

What is the optimal setup? A single large one on each side? Two per side? Is there any "science" regarding angle of attack?

Why the 172 you ask? It's a SSM autocross thing. Here is the current very rough prototype for my splitter and canards, but I am open to better ideas.
Thanks,
--Chris
http://racing.systemstrategies.com/C...anards_003.JPG
http://racing.systemstrategies.com/C...anards_004.JPG

WonTon 02-03-2010 10:45 PM

that looks pretty good! is that piece you got cut out within the limit?

SSM has alot of dumb rules it seems!

Full_Tilt_Boogie 02-03-2010 10:45 PM

On pro touring cars you usually see upright pieces along the outside used to separate the high and low pressure areas on the upper and lower sides of the canard, just like you see on a spoiler.

http://www.lotustalk.com/forums/atta...e-dsc03653.jpg

http://naknak.smugmug.com/photos/570521068_Uts5F-XL.jpg

http://image.importtuner.com/f/89805..._8+canards.jpg

I wish i could find better examples, but you get the idea

WonTon 02-03-2010 10:47 PM

^^^^^^ what he said!

i forgot all bout that!

Full_Tilt_Boogie 02-03-2010 10:49 PM

You ever see them on big money touring cars? with the crazy multi level canards and shit all over. I wish I could find some damn pics, haha

hustler 02-03-2010 10:56 PM

http://cdn-www.rsportscars.com/foto/...cedes_dtm2.jpg

Chris Swearingen 02-03-2010 10:56 PM


Originally Posted by WonTon (Post 517676)
that looks pretty good! is that piece you got cut out within the limit?

SSM has alot of dumb rules it seems!

My car would be sooooo much faster without rules, but then again so would everyone's. The good thing about the rules is that they are the same for everybody. Part of the challenge, for me at least, is to figure out how to make the most of what is allowed but still be 100% legal.

The one taped on is the "maximum" legal size. Nothing says it can't be smaller. I think the turned up edge is legal as well. The splitter is actually a couple of inches shorter than it can be. The final version may be a little bigger.

Chris Swearingen 02-03-2010 10:59 PM

Cool but slightly outside the rules. Can anyone tell where the splitter ends and the canards begin?
http://www.media.suzuki.com/auto/upl...onster_001.jpg
http://www.media.suzuki.com/auto/upl...pihcSpl_1M.jpg

KPLAFIN 02-03-2010 11:44 PM

1 Attachment(s)
Benz like them flat:

Attachment 200747

Stein 02-04-2010 12:04 AM


Originally Posted by Chris Swearingen (Post 517687)


L0oks like a friggen snow shovel. I don't doubt that it works and all of them are wearing them but come on...

Full_Tilt_Boogie 02-04-2010 12:08 AM


Originally Posted by Stein (Post 517717)
L0oks like a friggen snow shovel. I don't doubt that it works and all of them are wearing them but come on...

I'd daily drive it fo sho

Full_Tilt_Boogie 02-04-2010 12:43 AM

you could always do this

http://cache.gawker.com/assets/image...o_Scion_tC.jpg

WonTon 02-04-2010 01:16 AM

good god!

it looks so stupid it has to be functional! haha






its FWD, hah it needs all the downforce in the front it can get!

boileralum 02-04-2010 01:24 AM


Originally Posted by Stein (Post 517717)
L0oks like a friggen snow shovel. I don't doubt that it works and all of them are wearing them but come on...

Pretty sure that's the Pike's Peak Suzuki Escudo that dominated all the top speed records in Gran Turismo 1&2.

bellwilliam 02-04-2010 02:47 AM

canard is just like wing. it does stall if it is too steep. so anything over 25 degree is a no no. probably a little less.

canard gives very little down force comparing to splitter. my guess is less than 10% of total front down force. but I install it, because I use it more as a tire spat than a canard. front tires generates a ton of drag and lift.

fooger03 02-04-2010 08:13 AM


Originally Posted by bellwilliam (Post 517772)
canard is just like wing. it does stall if it is too steep. so anything over 25 degree is a no no. probably a little less.

+1,000

The turn-up on the outside edge of the canards is designed to help the canard to not stall by holding the high pressure onto the top side of the canard. It should be noted though, that a lot of these canard pictures are missing a turn down as well. You see, the bottom side of the canard is significantly lower pressure. If you "T" the edge of the canard (close off the high pressure up top AND the low pressure down bottom) instead of simply a turn-up, then you keep ambient air from spoiling the low pressure area beneath the canard. These turn-ups and "T"s literally make the canard act as if it had a larger area than it does. Does your 172 sq-in max limit the vertical area too, or just the horizontal surface?

You may want to consider looking into airfoils as well as canards. you will have to position an airfoil farther to the side of the car than a canard to get the benefit from it (and you may end up fuxxoring it up by running into crap b/c it's adding a couple inches to the width of the car), but in essence it would be a front-wing which would generate downforce much like a legitimate rear wing. It also wouldn't become nearly as much of a hinderance from an aero-drag perspective as a canard would. Just a thought, discard if you like. :D

Braineack 02-04-2010 08:33 AM

Canards
http://image.modified.com/f/tech/173...tc+canards.jpg
Nissan Skyline Gtr Jgtc Canards

Also known as dive planes or dive plates, since they resemble the winged appendages on submarines, canards help generate downforce in two different ways. First, the canard redirects the oncoming air's momentum upwards, which causes a downward force on the canard. This is only moderate, since the velocity near the skin is significantly slower than in the free stream. In addition, canards generate strong vortices that travel down the sides of the car and act as a barrier. If the canards are positioned correctly, these strong vortices act to keep high-pressure air around the car from entering the low-pressure underbody region, thus maintaining more downforce. If air was allowed to enter the underside, the pressure would inevitably rise, reducing downforce. Therefore, these strong vortices act like a virtual curtain or dam, restricting higher-pressure air around the car's sides from entering the underbody region. As a result, the low pressure under the car is maintained and downforce is maximized. Unfortunately, canards are not very efficient, since the strong vortices create a significant amount of drag. They are more useful for fine-tuning aerodynamic balance.

http://image.modified.com/f/15587105...front_view.jpg

Automotive Aerodynamics - Sport Compact Car Magazine

webby459 02-04-2010 08:57 AM

SSM aero rulez quoted below. Chris, did the Nov fastrack prop for the canards get adopted as written here? Just figured this would help in the discussion a little, canard stuff in italics, below:

L. Aerodynamic Aids: Wings may be added, removed, or modified.
Non-OE wings may only be attached to the rear deck/hatch area
behind the centerline of the rear axle. The total combined surface
area of all wings shall not exceed 8 square feet as calculated
per Section 12.9. The number of wing elements is limited to 2.
Wings, and any component thereof, may not extend beyond the
vehicle width, as defined by the outermost portion of the vehicle
doors, less mirrors, door handles, rub strips, and trim. In addition,
no portion of the wing or its components may be more than
6" forward of the rear axle, more than 0" beyond the rear most
portion of the bodywork, or more than 6" above the roofline of
the vehicle, regardless of body style. For convertibles and roadsters,
the highest portion of the windshield frame will be considered
the highest portion of the roof.
Reinforcements to the wing mounting area may be used, but
may serve no other purpose. Body panels to which a wing
mounts must remain functional (e.g. trunk lids and rear hatches
must open). Wing endplate surface area is limited to 200 square
inches each and limited to a maximum of two.

Add to 16.1.L: “Canards are allowed and may extend a maximum of 6 inches 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 12.10. Canard area may not
exceed 15% of total wing allowance. The sum of canard area and rear wing area may not exceed the total wing
allowance.”


M. Front splitters are allowed and shall be installed parallel to the
ground (within +/-3 degrees fore to aft) and may extend a maximum
of 6 inches from the front bodywork/fascia as viewed from
above. Splitters may not extend rearward past the centerline of
the front wheels. No portion of the splitter may extend beyond
the widest part of the front bumper/fascia as viewed from above.

Chris Swearingen 02-04-2010 08:57 AM


Originally Posted by The Rules
Canards are allowed and may extend a maximum of 6 inches 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 12.10. Canard area may not exceed 15% of
total wing allowance. The sum of canard area and rear wing area
may not exceed the total wing allowance.

I probably should, but don't care about any drag penalty. I am 300+ rwhp at around 2100 lbs and very rarely get out of second gear. (the 3.63 rear end may change that to never) I am going to take the conservative approach and say that the turn up on the ends would be considered part of the surface area.

I see a lot of the pictures that show two per side. Is that "better" or just more visually appealing?

I am waiting to hear back from the rules makers on the use of side skirts. I have some "designed" that will effectively seal the sides of the car.

So given the max downforce without regard to drag, and little need for generation of vortexes to seal the sides, what say you?

webby459 02-04-2010 09:06 AM


Originally Posted by webby459 (Post 517817)
No portion of the canard may extend past the widest part of the front bodywork/fascia as
viewed from above.

No portion of the splitter may extend beyond
the widest part of the front bumper/fascia as viewed from above.

Unfortunately, the above prevents Chris from using the canard as a tire spat, as William suggested. Can any of you smarties think of a way to shape the canard to resemble the function of a spat? I would think this would be of some benefit to Chris. Maybe leave the vertical end plane off the canard in order to direct turbulent airflow away from the tire/flare? Or, even better, use a vertical end plane presented at a longitudinal angle to direct airflow outside of the tire/flare area? Just thinking out loud.

webby459 02-04-2010 10:20 AM

Still thinking out loud. What if you thin out the canard a little in the direction lateral to the car. Then bring the leading edge either close to or touching the deck of the splitter. Then slope or rake the canard to try to blend it's trailing edge with the flare as much as possible within the rules.

Still fixated on trying to smooth the flow around that big meaty tire, especially below the flare. Anyone have a wind tunnel?

Chris Swearingen 02-04-2010 10:40 AM

I like the idea but .....

Is eliminating the tire drag a worthwhile trade off at autocross speeds? I spend a lot of a run with the tire turned anyway, so there is likely a lot of the tire that will be "out in the wind" even if I could effectively shield it in a straight line.

Next year when I cage the car and go faster and straighter for longer it may be more of an issue.

Keep the ideas coming:skid:

bellwilliam 02-04-2010 12:50 PM


Originally Posted by Chris Swearingen (Post 517849)
I like the idea but .....

Is eliminating the tire drag a worthwhile trade off at autocross speeds? I spend a lot of a run with the tire turned anyway, so there is likely a lot of the tire that will be "out in the wind" even if I could effectively shield it in a straight line.
:

it is not tire drag (at autocross speed) as much as the lift generated by tires. it is true that tires are turned away. but with tire spat, instead of 100% of tire treads not shielded, you have may be 50% of tires shielded.

as you know, at autocross speed, it has to be a BIG wing, and BIG splitter for it to matter, even then, very little. canard really does nothing at these speed imo. it doesn't do much at higher speed either (100mph). they are used for tuning.

Chris Swearingen 02-04-2010 02:39 PM


Originally Posted by bellwilliam (Post 517919)
it is not tire drag (at autocross speed) as much as the lift generated by tires. it is true that tires are turned away. but with tire spat, instead of 100% of tire treads not shielded, you have may be 50% of tires shielded.

as you know, at autocross speed, it has to be a BIG wing, and BIG splitter for it to matter, even then, very little. canard really does nothing at these speed imo. it doesn't do much at higher speed either (100mph). they are used for tuning.

How do we use them for tuning? The appear to me to be fixed. I would have assumed that they and the splitter were both "set" to produce the most downforce available and that the angle of attack on the rear wing was used for tuning the balance. My "top speed" in second is going from 69 to 74 mph with the gearing change. So we don't see 100, usually closer to 45 but on occasion the forces do build.

bellwilliam 02-04-2010 11:39 PM

tuning as bigger or smaller canard. some race car use fender size as a tuning device, but it is for 100MPH+ adjustment. I doubt anybody can feel a canard adjustment at 60mph.
Imo, canard adds down force in a Miata, not by the force generated by the device, but from acting as a tire spat, that blocks out air hitting bottom of tires, creating tire lift (which is worse than body lift).

in your case, I would design the canards to block out as much of front tires as possible. both to the side and bottom if possible.

turotufas 02-05-2010 05:13 AM


Originally Posted by Braineack (Post 517804)

One of my favorite images from SCC. Aint picked up modified yet, maybe next year. GRM is #1 right now I think.


Originally Posted by bellwilliam (Post 518281)
I doubt anybody can feel a canard adjustment at 60mph. Imo, canard adds down force in a Miata, not by the force generated by the device, but from acting as a tire spat, that blocks out air hitting bottom of tires, creating tire lift (which is worse than body lift).

in your case, I would design the canards to block out as much of front tires as possible. both to the side and bottom if possible.

I like the way you think. I never considered the effect that the tires have on the aerodynamics of the car due to them sticking out behind the bumper.

Midtenn 02-06-2010 11:06 AM

You've also got to remember that there needs to be support behind the canard. If not, all the force on it is just going to translate to flexing the bumper cover.

j_man 02-08-2010 09:31 PM


Originally Posted by turotufas (Post 518349)
One of my favorite images from SCC. Aint picked up modified yet, maybe next year. GRM is #1 right now I think.

Modified is not SCC. SCC went online - here is their new web site:
www.motoiq.com




thagr81 us 02-08-2010 09:35 PM

Thanks for the above link... Didn't know they moved to that site (well quite a few of the writers/editors).

turotufas 02-08-2010 10:24 PM

SCC was totally liquidated. Modified got a few contributors and things like the USCC. So its not quite as gay as it used to be. I still refuse to read it do!

That website is cool as shit though. Reminds me of my Nissan days. Eric Hsu, Dave Coleman, and Mike Kojima. Awesome!

bellwilliam 02-09-2010 05:08 PM

4 Attachment(s)

Originally Posted by turotufas (Post 518349)
I like the way you think. I never considered the effect that the tires have on the aerodynamics of the car due to them sticking out behind the bumper.

not just from sticking out behind bumper. but air hitting tires from underneath, and lifting tires off the ground.

here are some ugly canards, but idea is to use it as a tire spats.

front tire is 13.1% of total drag:
http://autospeed.com/cms/A_2455/article.html

an article on dive plane
http://www.reverie.ltd.uk/Downloads/Aerobytes-Oct08.pdf

albumleaf 02-09-2010 06:09 PM


Originally Posted by Braineack (Post 517804)
Canards
http://image.modified.com/f/tech/173...tc+canards.jpg
Nissan Skyline Gtr Jgtc Canards
First, the canard redirects the oncoming air's momentum upwards, which causes a downward force on the canard. This is only moderate, since the velocity near the skin is significantly slower than in the free stream.

Yes, flow at the surface of the canard is effectively zero, but at that speed the transition between zero and the "free stream" is going to be tiny. I don't buy that bit.


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