Wind tunnel

[Racefreak24]

I know it may seem somewhat extreme for what we do and I probably couldnt afford it anyway but is there a wind tunnel in the new england area where you can get downforce / drag tested and also, dow is downforce and drag measured? Is it lbs?


PS Great job to everyone in the cheap date......I cant believe how uneventful turn 3 was. (THATS GOOD!!!)

[lateapex911]

MIT, but you'll need nothing bigger than a 1/4 scale model, and better hire an engineer.

[CaptainWho]

Yarn, glue, camera, desolate stretch of road.

[gsbaker]

There is no cheap way to do this, although I do like Lefty's idea!

A good computer simulation will get you 80% of the answer at 10% of the cost. Find a mechanical engineer with access to CFD (Computational Fluid Dynamics) software, ideally one with a generic car model. It won't be your car's exact shape, but it's a basis for examining any changes you have in mind.

Or, put globs of water-based paint all over it and hit the Interstate.

[lateapex911]

OK, to be realistic, in IT, there isn't that much you can actually do legally, so a wind tunnel is way down the list of priorities.

But the air dam is free, so I guess the question becomes, what do you want your airdam to do?

I'd submit that you want it to lower drag, provide effective air management for brake, oil and water cooling, and provide reasonable downforce.

Well some of those things can be monitored very cheaply, and others can be deduced from instrumented testing.

There are of course, books written on the subject, but for a real guy/real world example, try going here.

http://forums.pelicanparts.com/showthread....20&pagenumber=1

It's a long thread, but there are lots of real world tuning and testing ideas. Jack is nothing if not industrious. And to do this sort of thing you have to be. I bet the cost to create an accurate scale model, and then rent a wind tunnel will be nearly a 100K when it's all said and done.

CFD consulting would be significantly less, but still very expensive.



One final idea would be to find a student who is interested in racing, and is in an engineering program and strike up a friendship. Of course, thats a lot different than hiring someone, but if he's not tooo tied up with his girfriend pursuit, his partying and his classwork, he might fit you in, LOL.

[kthomas]

Come on down to Lockheed Georgia, we'll try to fit you in. Tunnel is booked 4000 hours a year, and it's only $1000 per hour. Well within an IT budget...

[924Guy]

I REALLY like the idea of yarn on the interstate - could really pay dividends on that investment in bullet cameras! We do use those at work for data analysis on the outside of test cars.

Heck, you could even get away without plating/driving your car on the street, if you've got an open trailer and a low-slung tow vehicle!

[pgipson]

There was an article in Sports Car a couple of years ago about a guy in the Milwaukee area that did a lot of aero testing on his E prod Alfa (?) using models.

[gsbaker]

Michael Cudahy. Glendale, WI.

[gsbaker]

For you do-it-youselfers out there, here is an open source (free) CFD program that runs on open source (free) Linux. It sounds hokey and takes a certain minimum skill level, but the word on geek street is that this is some serious CFD grunt--so much so that some companies are making the switch to it.

I haven't used it (not a CFD kinda guy), but one gearhead I know and respect who does serious automotive design work mounted OpenFOAM on Ubuntu on an old P3-800MHz box and it ran fine--a little slow on that hardware of course, but he described it as "professional quality."

http://www.opencfd.co.uk/openfoam/index.html#openfoam

[planet6racing]

Thanks Gregg!!! Just what I was thinking for the new project car...

[Team SSR]

http://www.aerodynwindtunnel.com/index.html

[gsbaker]

Let us know how it goes, Bill. That whole subject is over my head, but I'd like your opinion on the software.

(If readers have an interest in Linux and would like to try it without committing to a full machine or partition, they should download Ubuntu and burn it to a CD. It's so small you can actually boot and run Linux from the CD alone, without affecting your hard drive. And it comes with a complete office suite and browser.)