Aero Data

[ben]

Would anyone care to speculate or present data on the drag coefficient of an average wingless FSAE car?

I had thought around 0.9, but I can't remember where I might of got that from.

Also do any of the guys running wings (Scott at Monash?) have any idea what a realistic Lhttp://fsae.com/groupee_common/emoticons/icon_biggrin.gif ratio for your aero package is?

Cheers guys

Ben

[ben]

Would anyone care to speculate or present data on the drag coefficient of an average wingless FSAE car?

I had thought around 0.9, but I can't remember where I might of got that from.

Also do any of the guys running wings (Scott at Monash?) have any idea what a realistic Lhttp://fsae.com/groupee_common/emoticons/icon_biggrin.gif ratio for your aero package is?

Cheers guys

Ben

[SimonUK]

Hi Ben

Our scale model has a Cd of around 0.95 without aero and about 1.1 with our aero package.

aerodynamic these things are aren't they ? http://fsae.com/groupee_common/emoticons/icon_smile.gif

HTH

Si

[ben]

Cheers dude.

I'm assuming you're from Imperial? what scale did you do that at?

BTW I'm currently putting together a data set to run in my lap time simulation, which should be finished within the week, hence the need for the data.

Ben

[SimonUK]

Nah I'm not quite that clever, I at hertfordshire.

Model is 30% scale and we've had some very encouraging results from the wind tunnel.

I imagine you need the info for ADAMS, Ive seen our suspension man (Stu) doing some simulations. I believe he went on the same course as you.

[Mark Bacchetti]

Ben,

What software are you using for lap simulation? ADAMS/3D Road?

Mark
Cal Poly Pomona

[Scott Wordley]

Hey Ben,

Before I start throwing round figures I just wanted to say that for these cars I think that its probably better to think in terms forces with regards to the aero stuff, particularly if we are comparing winged cars with unwinged cars. The obvious difference being the HUGE difference in frontal area through the potential addition of a rear wing.

Anyhow we measured a CD of 1.0 and a small amount of lift with no wings

Add wings like ours and you can count on doubling your drag FORCE. As for CL it all depends on how good your wings are and how well they are optimised. If you have good tunnel facilities and time on your hands you might manage a CL of 2 or above.

Is there any data (CFD or Tunnel) ngetting round on those Imperial wings?

[ben]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by SimonUK:
Nah I'm not quite that clever, I at hertfordshire.

Model is 30% scale and we've had some very encouraging results from the wind tunnel.

I imagine you need the info for ADAMS, Ive seen our suspension man (Stu) doing some simulations. I believe he went on the same course as you. <HR></BLOCKQUOTE>

Yeah, I was on the ADAMS course with Stu.

The LTS I'm using is a steady-state program I've written from scratch in Matlab. Its taught me a lot about mathematical modelling that should help me with any ADAMS work that comes later.

Cheers for the data Scott. You guys still on for F Student?

Ben

[Sam]

and you get fully sick batmobile eh scotty??

[Fully Sick Batmobile]

fully



.

[Scott Wordley]

We'll be there man.

Most of us will be arriving around the 22nd of June. Just enough time to check out Festival of Speed before heading your way.

Can't wait

[ben]

Just a thought, what sort of mass are we talking for your aero package Scott?

Ben

[Scott Wordley]

Say 12-15kg with mounts? We're trying to get some weight out of ours before the UK.

[PatClarke]

Hi Scott,
Why do I have this sneaking suspicion that your download averages about 12-15kg? http://fsae.com/groupee_common/emoticons/icon_wink.gif
Just kidding mate. Ill be in Melbourne in early May. Maybe we can catch up?
PDR

[Disco]

Pat,
Did your sneaking suspicion come about before or after their first place in the autocross??(haha)

Cheers
Steve

[Kevin Hayward]

C'mon Frank,

I had a look at the times.

Monash were first out on a dusty track and in over about ten timed laps the times were within a shade over 1 sec from lowest to highest. This with a best time that is in the top 5. All the other teams in that 5 had a difference of about 3 seconds between slowest and fastest laps of an individual driver.

What does this mean?

Maybe Monash would have gone even faster given more laps?

Maybe their drivers are just exceptional and were getting the absolute most out of the car (Though I think Hester ... hopefully I got that right ... was clearly the best driver)

Maybe they were just not able to go as fast and fluked the autocross?

Maybe they just got the best track conditions?

But if all wings were good for was putting in those lap times consistently they would be worth having.

...

All I can say is that after the dynamic performance of the Monash car I think that other teams would be mad to discount wings completely.

I really hope the Monash guys get themselves fully sorted for the UK so we can see if the wings really give them an edge or not.

Kev

UWA Motorsport

[Frank]

sorry, i have removed that rude post....

have had a bad day, please excuse me

[Joel Miller]

Monash's speed was impressive http://fsae.com/groupee_common/emoticons/icon_eek.gif. Is anyone following their lead and developing an aero package for the first time this year?

[The guru of guru's]

We were considering putting a little yellow flag on our car..like the ones found on kids bikes.....Would this be considered as an aero package?

Cheers

[ben]

I can't wait until we see Monash here in the UK. We've never had the resources to develop an aero package and I think many uni's who run aero packages don't have the resources to develop them properly.

Monash clearly do have the tools, and I'm interested to see how it translates onto the track.

Ben

[Scott Wordley]

Kev, from an inexperienced drivers perspective the wings definitely made the car much more predictable and easier to drive initial. The difficult part is learning to exploit the downforce to its full potential as i think wingman commented on in a previous aero thread. With a high aero load to car mass ratio the car becomes capable of corning harder than your intuitively used to, plus its speed dependant so another factor to juggle in the mind of the driver.

Pat, it would be good to catch you when your in Melbourne, give me a call(0414852369) a few days before and we'll show you the car before it leaves and maybe go out for a beer.

[Joel Miller]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by ben:
We've never had the resources to develop an aero package and I think many uni's who run aero packages don't have the resources to develop them properly. <HR></BLOCKQUOTE>

Ben, I see you guys had an aero pack for the #219 car, but dropped it for the following year. What was the reason for this? Was it a recognition of limited resources or was it a perception that the wings didn't/wouldn't lead to performance gains? I'm guessing that you haven't lost the faith, given that you kicked this thread off...

I think teams like Monash and UTA have presented very convincing cases for the benefits of "download". But there seems to be a number of teams that have dabbled with aero and then decided against it. Cornell, Rensselaer and of course Birmingham come to mind. Anyone care to comment on the factors behind these decisions?

Respec'

[ben]

Yeah, the non-aero car that raced that year beat the aero car. It was more a homage to Cal Poly who had been based at our uni during their winning FStudent campaign.

We don't have a wind tunnel and as such, now I have taken over as tech director the focus has been on a small, well packaged, and light car.

Ben