Author Topic: A2 WIND TUNNEL SPEED REPORTS  (Read 20459 times)

0 Members and 1 Guest are viewing this topic.

Offline Seldom Seen Slim

  • Nancy and me and the pit bike
  • Administrator
  • Hero Member
  • ***
  • Posts: 13158
  • Nancy -- 201.913 mph record on a production ZX15!
    • Nancy and Jon's personal website.
Re: A2 WIND TUNNEL SPEED REPORTS
« Reply #30 on: September 09, 2008, 03:05:41 PM »
Kaz (and everyone, for that matter):  For shipping your bike (or anything) -- you might want to check out www.uship.com.  It's sort of an eBay for shipping, in that carriers look there for loads that need to be moved, and then bid on them.  You might get Mom and Dad that have sold the house and now drive a hotshot from coast to coast, or you might get a regular freight company looking to get some revenue on a backhaul that'd otherwise be empty.  I've used them, and they offer door-to-door service.  Pick the price and other arrangements that suit your need.

There are several trucking firms that move bikes specifically -- but they're often more expensive, being aimed at either the crowd that has more money than time to shop, or the crowd that has show/custom bikes and money isn't a big deal.  Try Roadway, I think it is.
Jon E. Wennerberg
 a/k/a Seldom Seen Slim
 Skandia, Michigan
 (that's way up north)
2 Club member x2
Owner of landracing.com

Offline willieworld

  • Hero Member
  • *****
  • Posts: 1818
Re: A2 WIND TUNNEL SPEED REPORTS
« Reply #31 on: September 09, 2008, 03:52:59 PM »
kaz  there is a wind tunnel much closer to you --ill find out about a price---im building a new bike and i would like some tunnel time probibly around april of 09 if you can wait until then maybe we could go together   let me know   willie buchta
willie-dpombatmir-buchta

Blue

  • Guest
Re: A2 WIND TUNNEL SPEED REPORTS
« Reply #32 on: September 09, 2008, 07:57:36 PM »
kaz  there is a wind tunnel much closer to you --ill find out about a price---im building a new bike and i would like some tunnel time probibly around april of 09 if you can wait until then maybe we could go together   let me know   willie buchta
Willie,
You need "Race Car Aerodynamics: Designing for Speed" by Joseph Katz, ISBN 0-8376-0142-8  He has a whole chapter on wind tunnels and how to correct for ground effects. 

The following is HIGHLY simplified explanation of wind tunnels.  Sizing your tunnel should be based on about 2X your vehicle width and height.  The bigger the better, but fans get expensive really quickly.  Fans are available to move a given number of CFM at a very low airspeed, so it is common to use a 3 to 10X cross section increase and literally fill it with fans.  For your application you may be able to get away with just one large HVAC fan.  This would be great for you since they are belt driven, and you can change speeds by changing belts.  More velocity than the motor will pull?  Get a second motor and add another belt.  It is best if the inlet of the tunnel is a bell mouth (like a velocity stack inlet) that is at least 4X of the tunnel test section area and about 2X as long as it is high or wide, whichever is greater.  This gives the incoming air plenty of time to straighten out.

The big issue is the instrumentation.  Objects in wind tunnels are normally mounted on a "sting" mounted to a "balance".  Plenty of books on this, even Wikepedia may have a design.  This takes up a lot of room and constitutes a large portion of the cost of a tunnel.

If you just want to look at smoke and tufts, it's a lot easier.  One thing you might look into is mounting a large sheet of acrylic as your ground effect diverter so that you can crawl under and look up at the belly (put tufts there too).  Lots of drag underneath these cars that no one ever looks at.

Blue

  • Guest
Re: A2 WIND TUNNEL SPEED REPORTS
« Reply #33 on: September 09, 2008, 08:02:06 PM »
Blue;

Thanks for the post. Do you know of any affordable computer programs that can analyze airflow, even in 2-D?

Regards, Neil  Tucson, AZ
There are many that are cheap and simple, unfortunately, they don't model separation very well (or at all) and hence are ridiculously inaccurate for LSR.  I write my own for simple things.  Good code with useful automated meshing and post processing (display of data) is expensive and pretty user hostile.

I was asked to find some cheap and simple standard by more than one person.  I'm looking into it, I may have a solution later this year.

Offline manta22

  • Hero Member
  • *****
  • Posts: 4137
  • What, me worry?
Re: A2 WIND TUNNEL SPEED REPORTS
« Reply #34 on: September 09, 2008, 08:10:40 PM »
Blue;

Thanks-- even a minimum program will be better than my intuition.

Regards, Neil  Tucson, AZ
Regards, Neil  Tucson, AZ

Offline sockjohn

  • Sr. Member
  • ****
  • Posts: 364
Re: A2 WIND TUNNEL SPEED REPORTS
« Reply #35 on: September 09, 2008, 09:29:23 PM »
FWIW, Texas A&M in College Station has a wind tunnel, and is located only 3 1/2 hours from where the Texas Mile is located.

http://lswt.tamu.edu/index.htm

I'm sure you've heard of this, but here it is:
http://www.texasmile.net/

Combining the trips might help expenses, especially for those in the Midwest or West Coast.

I hope this doesn't detract from A2WindTunnels help here, but I know for many that may not be a good option due to the travel involved.

Super Kaz

  • Guest
Re: A2 WIND TUNNEL SPEED REPORTS
« Reply #36 on: September 10, 2008, 01:35:14 AM »
kaz  there is a wind tunnel much closer to you --ill find out about a price---im building a new bike and i would like some tunnel time probibly around april of 09 if you can wait until then maybe we could go together   let me know   willie buchta

Willie,
I'm on :-D!
I Might try to get a head start if possible,but either way I'LL be your Swamper :cheers:
A good BASELINE would be my start .Then I'll put it to use{RACING IT}, and then return with you and compair the differences :-D!
A2 need any Test Rider's/Pilots? I'LL ride or race just about anything for the name of science :mrgreen:.
Talk to ya soon,
Kaz............

Offline edweldon

  • Full Member
  • ***
  • Posts: 160
Re: A2 WIND TUNNEL SPEED REPORTS
« Reply #37 on: September 11, 2008, 03:09:11 AM »
Willie,
You need "Race Car Aerodynamics: Designing for Speed" by Joseph Katz, ISBN 0-8376-0142-8  He has a whole chapter on wind tunnels and how to correct for ground effects. 
Blue --
You've got me dusting off my copy of Katz's book and wading through chapter 3.  I'm not sure this is a good sign........
Ed Weldon
Captain Eddie's Day Old Fish Market -- home of the Bonneville Salt Fish
Featuring the modern miracle of mechanical refrigeration.

Offline A2WindTunnel

  • Full Member
  • ***
  • Posts: 224
    • A2 Wind Tunnel, LLC.
Re: A2 WIND TUNNEL SPEED REPORTS
« Reply #38 on: September 16, 2008, 03:43:37 PM »
I have a few vid's up of Eakers tail spin and a 300mph (unofficial run) with the firebird.  The spin is in slow motion and the quality is very poor, but that is all Eaker had back in 1989.  Notice the rear glass get sucked of the car and shot in the air. See on our youtube page…


http://www.youtube.com/watch?v=T66EwAm3CwM

http://www.youtube.com/watch?v=LYV0GiNDr6E


Thanks for all the feed back on wind tunnel testing that is going on here from the members of landracing.  I am happy that that the issue about wind tunnel testing is out, and that people know the importance of aero from performance & safety.  I do not expect people to come all the way out to NC for a test, but A2 is offering the 3 run test at an extremely low cost, and hope that people will take advantage of this offer to help educate them selves about where there car is aerodynamically, and in which ways/areas there is room for improvement.

I had a test recently that I can loosely talk about.  All information learned in A2 is the customers and not for us to discuss, but have permission to generally speak about this test.  The customer (1st time) came in for a 3 hour test, and reduced the drag by 0.085 (counts CD), which at the speed he is running (220) equated to 130 HP.  All while we were able to keep the same downforce balance (front to rear). That was 130 HP for under $1200.  This is just one case, but shows that the cost of tunnel testing can be less then trying to put HP in your car.  A wind tunnel is for your car the same as a dyno is for your engine.  You can tune and optimize (within the rules) your cars body to reduce drag, correct aerodynamic handling issues etc…

Dave
The answers are blowing in the wind...
www.A2WT.com
http://www.facebook.com/pages/AERODYN-A2-WIND-TUNNEL/259986785465
@A2WindTunnel #A2WindTunnel

Offline A2WindTunnel

  • Full Member
  • ***
  • Posts: 224
    • A2 Wind Tunnel, LLC.
Re: A2 WIND TUNNEL SPEED REPORTS
« Reply #39 on: September 16, 2008, 03:55:05 PM »
PS:  The glass is the first to come off and is very very faint to see, but launches what seems to be at least 100'.  There is a bigger piece that comes off second that just tumbles with the car.
The answers are blowing in the wind...
www.A2WT.com
http://www.facebook.com/pages/AERODYN-A2-WIND-TUNNEL/259986785465
@A2WindTunnel #A2WindTunnel

Offline bvillercr

  • Hero Member
  • *****
  • Posts: 2291
Re: A2 WIND TUNNEL SPEED REPORTS
« Reply #40 on: September 16, 2008, 06:03:11 PM »
 A2
Do you know why it spun? Tire spin or lift or? and what they did to correct problem.
Did they use nos to cool intercooler?

                             JL222

Offline A2WindTunnel

  • Full Member
  • ***
  • Posts: 224
    • A2 Wind Tunnel, LLC.
Re: A2 WIND TUNNEL SPEED REPORTS
« Reply #41 on: September 18, 2008, 09:24:18 AM »

For anyone interested, there are a few articles about aero that im sure most of you might have seen.  For those who have not, here are a few that have good aero tips and talk about wind tunnel testing.

http://www.hotrod.com/techarticles/body/113_0703_car_aerodynamics/index.html

http://www.hotrod.com/techarticles/body/hdrp_0609_aero_tricks_tips/index.html

The answers are blowing in the wind...
www.A2WT.com
http://www.facebook.com/pages/AERODYN-A2-WIND-TUNNEL/259986785465
@A2WindTunnel #A2WindTunnel

Offline bvillercr

  • Hero Member
  • *****
  • Posts: 2291
Re: A2 WIND TUNNEL SPEED REPORTS
« Reply #42 on: September 18, 2008, 11:02:31 AM »
Great info, thanks. :-D

Offline A2WindTunnel

  • Full Member
  • ***
  • Posts: 224
    • A2 Wind Tunnel, LLC.
Re: A2 WIND TUNNEL SPEED REPORTS
« Reply #43 on: September 18, 2008, 11:50:18 AM »
And to answer the question you had.  Gary said there were a few things that went wrong with the spin, and they had configured the car a little different from the previous speed runs a month or so earlier. (I will keep it short) The car was going to be on display at SEMA (1989) and Gary was asked to convert the firebird from an 88’ to an 89’ for the show, which was not much more then a different style rear wing.  This new style wing had some 100 counts of rear downforce less (0.100) which added to make the car very unstable at high speeds.  Since production cars are already aerodynamically unstable at those speeds, the new wing made it even worse from his last runs on the salt weeks before.  He was also the only one on the salts that day, and from what I am told a very fine salt powder that settles on the salt which made traction more of an issue for the first run.  With the downforce loss to the rear they had to weight the car heavily to the rear making the CG far back which made the car like a pendulum once the rear started fish tailing it was over in less then a second.

He did fix the car with a new hood and rear glass that was taken off a car at a local body shop, and ran the next day, but the engine blew getting into the 5 mile.  To give you an idea of how fast he was going…by his tach and gearing it was running a calculated 307mph.  When it blew going into the 5 mile Gary pushed in the clutch and coasted through the 5mi (on fire) at an average of 288mph.

And the Nitrous Oxide was to cool the inner cooler.
The answers are blowing in the wind...
www.A2WT.com
http://www.facebook.com/pages/AERODYN-A2-WIND-TUNNEL/259986785465
@A2WindTunnel #A2WindTunnel