Wind Tunnel Advice

[manifest]

Considering we are on a limited budget would we be better off finding a small (1/8 scale or so) wind tunnel and building a scale model of our Datsun modified sports project or just building a few different foam frontends for the actual car and taking it to A2 or such facilities?  I work at a national laboratory here in TN and have connections to the University of Tennessee Engineering Dept, so I believe I can find a small tunnel but I'm not really sure how worth while it would be for us in the long term.

Any and all thoughts please.

Zach

[Blue]

Cover it with yarn tufts and run it down the highway at legal speeds.  Make sure the photo vehicle does not interfere with the air flow, use a stationary photographer or GoPro cameras duct taped on the car itself.  I have put over 100 mph on three types of aircraft with nothing more.

[Richard 2]

Cover it with yarn tufts and run it down the highway at legal speeds.  Make sure the photo vehicle does not interfere with the air flow, use a stationary photographer or GoPro cameras duct taped on the car itself.  I have put over 100 mph on three types of aircraft with nothing more.

Blue, What do we want to see the yarn doing or not doing.

[hotrod]

Tuft tests have already been discussed and I have some pictures that you might find useful.

Look starting at post #223 on this thread.

http://www.landracing.com/forum/index.php/topic,8252.223.html

If the flow is attached the tufts will lay down smoothly against the car body.
If the flow has transitioned to turbulent the will start to flutter, and if the flow separates completely they can point almost any direction.

Larry

[Tman]

Zach, have you looked at the treit and Davenport thread? A week or so ago they showered thier model in a mini tunnel.

[Blue]

Tuft tests have already been discussed and I have some pictures that you might find useful.

Look starting at post #223 on this thread.

http://www.landracing.com/forum/index.php/topic,8252.223.html

If the flow is attached the tufts will lay down smoothly against the car body.
If the flow has transitioned to turbulent the will start to flutter, and if the flow separates completely they can point almost any direction.

Larry

That's about it. Test, tape on foam and cardboard modifications, test again.  Post pictures.

[manifest]

Yes Tman, seeing the post with the streamliner is kind of what got me thinking more about it.  I know the bigger the scale model the better results you will get in a small tunnel.  Once we get the model done it would be much easier to change nose design and rear spoilers, but is it worth it?  Or would we be better off building a frontend out of foam and testing it before we put it into steel form?  Running it down the road is fine but getting an aero nose on the car which is attractive also is the main objective without having to build and redesign more than once.  My good friends the Barillaro brothers (barillaro speed emporium, knoxville tn) are great metal workers but I cant ask them to build the same part over and over.  

manifestofspeed.blogspot.com

Zach

[Tman]

Yes Tman, seeing the post with the streamliner is kind of what got me thinking more about it.  I know the bigger the scale model the better results you will get in a small tunnel.  Once we get the model done it would be much easier to change nose design and rear spoilers, but is it worth it?  Or would we be better off building a frontend out of foam and testing it before we put it into steel form?  Running it down the road is fine but getting an aero nose on the car which is attractive also is the main objective without having to build and redesign more than once.  My good friends the Barillaro brothers (barillaro speed emporium, knoxville tn) are great metal workers but I cant ask them to build the same part over and over.  

manifestofspeed.blogspot.com

Zach

Is this for your Datsun? If so, you should be able to find a plastic scale model to play with?

[Tman]

Dig your blog BTW.

[Richard 2]

I like the oil method looks more exact.

[Cajun Kid]

Zach,

I live an hour from A2 Wind Tunnel,,, I jusr spoke with them last week and the 2011 prices have increased a bit.

$460 per hour.  I need to check a few things on my Stude and while there with all this spolier and safety discussion I was going to put my car in backwards and test to see how the rear lifts with altered style rear spoiler.  I was then going to test a hinged design and flaps in the spoiler,,

However after talking with them, the time involved to take the car out, re set it backwards and make the tests would cost another $2,000 that I don't have.

So I understand your budget concerns.

Good luck.

Charles

[wobblywalrus]

There is a fellow on this website that does computer modeling of his lakester aero.  I cannot remember who it is or I would give it to you.

Full scale wind tunnel testing has this one advantage, you know if you have it right and can be satisfied.  The old trial and error method cannot provide this.  A person says to himself "Is this the best it can be? Do I need to do something else?"  A fellow simply does not know when he has it as good as it can be.     

[Richard 2]

Zach,

I live an hour from A2 Wind Tunnel,,, I just spoke with them last week and the 2011 prices have increased a bit.

$460 per hour.  I need to check a few things on my Stude and while there with all this spolier and safety discussion I was going to put my car in backwards and test to see how the rear lifts with altered style rear spoiler.  I was then going to test a hinged design and flaps in the spoiler,,

However after talking with them, the time involved to take the car out, re set it backwards and make the tests would cost another $2,000 that I don't have.




Charles, Do they have people waiting to use the wind tunnel, are they that busy? Maybe we should be in the wind tunnel business.

Rick

[manifest]

Yes it is for the datsun. 

Yea Charles I know how money can cramp the pursuit of speed.  We are used to running production based class (NHRA Super Stock and Production with our Ghia in LSR at Maxton and Bville) so this freedom to do aero tricks is a bit overwhelming.

Thanks

Zach

[Cajun Kid]

Maybe I can ask for a "Safety Grant"  from  SCTA  to provide them with the Test Results / Data ??

A $2,000 Grant would go a long way in helping answer a few questions about spoiler lift when a car goes backwards...

Just a thought.

Charles