Auburn Formula SAE 2011 Rollout

[Flying Dutchman]

While many of our club members were competing at the Dixie Nationals, the Auburn FSAE team rolled out their new 2011 formula car at the Shelby Engineering building on the Auburn campus this past Saturday, 3/12. Of course Auburn's fiercely proud of its engineering department and its students and this year is no exception. Under the new 2011 FSAE rules the teams are allowed to extend the aeordynamics beyond the rear wheels. And if you can permit a proud AU dad to brag for a moment, my son Kurt designed and built the aeor package for the car. He has been working on it since last June and made it out of carbon fiber. It is quite the buzz in FSAE circles because it is a radical design. I have attached a couple of pictures since they are worth a thousand words. By the way, it actually works producing over 200 lbs. of down force at 40 MPH!
Testing and tuning has already started. The team will be at the Michelen test facility in Laurens, SC this coming weekend. Hopefully, Auburn will have a good showing at the international competion held at Michigan International Speedway this May. I will keep you posted on Auburn's progress.

Charlie

[TouringBubble]

Do they have a small wind tunnel to test with there, or was it designed completely in the virtual world? I'd love to see more pics of the aero design as I like to dabble in fluid dynamics myself and would like to see what's so "radical" about it. Looks like it's focused on lift reduction rather than downforce, which I like.

[chuck schultz]

All of the relatively recent SAE cars I've seen seem to have fairly high noses. Is there some kind of minimum internal measurement for safety or to prevent teams with smaller drivers from having an advantage, or is it something else?

[jimkana]

The car looks great! Very Purposeful, yet it has some styling to it, which is always hard to mesh. I hope the team does very well this year with the car.

War Eagle!

[TouringBubble]

All of the relatively recent SAE cars I've seen seem to have fairly high noses. Is there some kind of minimum internal measurement for safety or to prevent teams with smaller drivers from having an advantage, or is it something else?

It may be to get more air under the car so the aero can work better. Sounds backward, I know ... but if basically all of your aero is on the bottom and sides of the vehicle, there is no need to flow extra air on top, especially with an exposed cockpit.

[Mowgli87]

It's been a while since I've posted here, but I feel obligated to answer a couple questions.

Do they have a small wind tunnel to test with there, or was it designed completely in the virtual world? I'd love to see more pics of the aero design as I like to dabble in fluid dynamics myself and would like to see what's so "radical" about it. Looks like it's focused on lift reduction rather than downforce, which I like.

No, we don't have access to a wind tunnel. All of the validity of the diffuser has been simulated thus far. We do have plans however to run some experiments during our testing phase though. Basically we'll take a series of controlled speed and weight runs with and without the diffuser. We'll use linear potentiometers mounted in line with the suspension push rods to measure ride height. Since we know the total car + driver weight, the weight split, and the spring rates, we should be able to determine a pretty decent estimated down force. And on that note, yes the diffuser is supposed to actually produce down force, and not just cancel lift. Or more stated more accurately it will provide a drop in pressure underneath the car. Basic laws of physics will force the car to be sucked down as more air tries to push it's way past the diffuser to fill the void.

All of the relatively recent SAE cars I've seen seem to have fairly high noses. Is there some kind of minimum internal measurement for safety or to prevent teams with smaller drivers from having an advantage, or is it something else?

This is due to a template rule that was passed after 2008. I think Auburn was actually one of the teams that persuaded that rule. Our 2008 car was TIGHT. All of the drivers bashed their shins on the steering rack during egress. Judges didn't like the fact the one could easily get a foot hung up on something, so they put an end to the problem before it got out of hand. We now have to be able to pass a designated template board forward through the front tunnel and another vertically through the cockpit.

I was driving the car Saturday during the presentation. Having driven 4 of our previously successful cars, I honestly think 2011 is going to be the fastest car Auburn has ever produced. Hopefully we'll be able to make it to a few points events with it this spring so you guys can see it in action.

Until then this might have to suffice:

http://www.youtube.com/watch?v=Dm1OoZP35Vw

[TouringBubble]

And on that note, yes the diffuser is supposed to actually produce down force, and not just cancel lift. Or more stated more accurately it will provide a drop in pressure underneath the car. Basic laws of physics will force the car to be sucked down as more air tries to push it's way past the diffuser to fill the void.

That's what I meant, but I stated it wrong. I meant that you were pulling the car down rather than pushing it, which produces downforce/cancels lift with much less drag than a spoiler.

To further clarify ...

LIFT <---- 0 ----> DOWNFORCE

There are multiple ways to get where you want to on the scale with different amounts of drag associated.

[Flying Dutchman]

Additional Picture

Here is a photo of the rear of the car. Perhaps this will help in understanding the diffuser concept a little more clearly.

[Mowgli87]

Here's a simulation that Kurt did using Ansys. I believe he modeled that to show the velocity of air (moving dots) as it travels underneath the diffuser.

http://www.youtube.com/watch?v=HWK0IDqtGFM