wind pattern from a rotating wheel (m/c)

[Harold Bettes]

Guys,
There is some decent data on the flow over rotating / covered / uncovered wheels in a few easy to grap publications.

First is Race Car Aerodynamics by Joseph Katz ISBN 0-8376-0142-8

Next is Vehicle Aerodynamics Recent Progress SAE-855 ISBN 1-56091-119-0
Made up of various SAE papers.

Sorry that I did not post this earlier. I thought that I had done so. So much for total recall being the sign of a healthy mind! LOL

Regards to All,
HB2

[Richard Thomason]

harold- there are a lot more things that can be a sign or not of a healthy mind/body/ or whatever.

[DahMurf]

First is Race Car Aerodynamics by Joseph Katz ISBN 0-8376-0142-8

Next is Vehicle Aerodynamics Recent Progress SAE-855 ISBN 1-56091-119-0
Made up of various SAE papers.

Harold,
 Are these both from a car perspective (not a motorcycle perspective)?
Thanks!
Deb

[Harold Bettes]

The references are for covered and uncovered wheels. Could apply to mc, autos, aircraft, etc. The study of these sort of things can be adapted to various applications. However, if you can be patient, I can perhaps get some specific information on motorcycles done in the USAFA low speed tunnel(s) and perhaps some othere mc related information. I do know that the previous reference to the anti-pumping device (simplified) is correct.

You know, it is fairly easy to build a "profile tunnel" so that you can take a look at how smoke or other flow visulation tools allow you to see patterns around and through devices. You can use a regular flowbench as the signal generator or build a much more simple device.

Regards,
HB2
Snowed-in The High Country

[JackD]

THX Harold for the observation about anti-pumping.
One can read up and study the theory in reference manuals from every where.
But until Manuel simply understands it , it won't do him any good.

"Theoretical records are set by theoretical race vehicles."

[Harold Bettes]

I have never understood why some (most) of the folks at Bonneville go around and knock the salt out of the wheel wells on the fendered vehicles. The salt is built up and performs very much like the anti pumper scheme that you mentioned. The buildup of salt directly behind the wheel/tire units are actually trying their very best to help streamline and decrease the exit loss of the rotating pumps.

Let me see, it is something like the relative speed of the wheel/tire at the top vs the bottom and the traction surface.....or something like that. LOL

SO, I guess a guy could make similar devices out of either ethafoam or styrofoam and sort of "seed" the salt buildup.....well, at least the stuff is white (so it looks right).

Regards,
HB2

[JackD]

Harold has figured out the wet salt collects in the low pressure area that you would do well to fill to allow the air to go by cleaner and won't shut up.
He even mentioned Styrofoam !
What can be done ?  LOL

[Harold Bettes]

Oh yes, I will now start to shut up on the subject....Now that I have learned that you are a C130 guy!
You probably don't like the "safety nets" 'cause they remind you of the seat webbing! LOL

You probably didn't bother to wear a safety tether after a while either. LOL

Guess I had better LOLEX outa here.

Regards,
HB2

[JackD]

Send a 10k load plus the pallet from the front of the bay that is trimmed to fly low and slow ,out the back door by tossing a chute will cause a 130 to do strange things.
It makes a lot of other stuff seem easy.
 

[Dean Los Angeles]

You may have seen Jack drop a load or two and just didn't realize it.

To refresh your memory:
http://www.micom.net/oops/Air-drops.wmv
Bonus! Jack's top secret Bonneville launch technique in this video!!!

[JackD]

Those were all test shots at Eglin AFB.
Our stuff was in RVN in 69 and the first thing that is not shown was the big booms from the big bombs that cleared the jungle and stuff.
Someday, ask me about building the World's Largest Tit with one of those 60ft chutes painted pink.
 It was a real photo opportunity.
Those in the film were all sissy drops with nobody shooting at you,  LOL

SSGT Dolan  555 CES-USAF 66-69

[roadtrip]

way off topic ....... but ...........

Don't know what you were dropping or where you were dropping it but THANKS for doing it.

Sgt. E-5 Strong  2/17 Artillery  Binh Dinh Province '68

DS

[JackD]

Knowing how to keep yer head down and yer butt too was a real important lesson in streamlining and was very effective on other things like going fast on a motorcycle.
If you didn't learn those things fast, you were going to go fast ,but not on a motorcycle.  LOL

[Harold Bettes]

Seen the inside (while riding) and the outside (while entering/exiting and during resupply) of 130's and learned early on that when it is your turn it is your turn. Very fortunate that it has not yet been time to punch my ticket. It does however make one appreciative of the little things.

And you Jack, might have snorted too much agent orange! LOL

And the only way that they will get me on a chopper again is on flight for life if I can't fight back!LOL

The Spectre AC130s that are flying today have undergone (some not all) a field mod that cleans the things up so that they can stay on station longer. All due to the applied naivete of some AFA Cadets that just wondered "what if" and accomplished same.

Cleaning up what is already working is not for everybody. Sorta like camouflage in that what you see is not necessarily what you get.

Regards to All,
HB2

[Richard Thomason]

Way over my head and beyond my expertise, but we have used the same material in the orchards for years (without the dye). Don't know what that means. Maybe that's my problem. Maybe that's what makes us want to go fast. On the subject of salt buildup in wheelwells, I remember when Don Debring first started, he was running really fast for the size for his power plant. Don't remember exactly what size but it was the motor out of his wife's car. Down run went great, I think it was in excess of 260 mph and on the return run things were not going as well and Don just kept upping the boost as the run progressed until it blew the motor up. It turns out that the wheel wells were being packed with salt and acting as a brake. You need to have at least enough room for the salt to not drag on the tires. Every year the salt is different. Need to be prepared for any and all eventualities.