[meteorite-list] Re:Hypersonic wind tunnel testing?

From: j.divelbiss_at_att.net <j.divelbiss_at_meteoritecentral.com>
Date: Thu Apr 22 10:16:35 2004
Message-ID: <20030824234250.2357B536DE_at_pairlist.net>

Elton and Tom,

I agree with Elton in saying that to set something up in a real wind tunnel
would be a really difficut to actually acquire "free" time in such a
facility. Maybe someone would volunteer a facility to do so.

The ideal way to do it would be get some engineer (mechanical, aeronautical,
etc) who has access to CFD modeling (or computational fluid dynamics) to set
up a model using different shapes of oriented meteorites and/or nosecones.
The difficult part of setting up such a model would be describing the piece
in CAD (computer aided drafting) so that the model could build a calculation
grid around it. However the combination of CAD skills and someone proficient
in CFD would easily get to some great information on a fairly tranquil state
of the last stages of an ideal meteor fall. One would have to assume a
stabilized flight to see the velocity vectors, forces, temperatures possibly,
etc. that occur around oriented flight. Throw spin into the picture...WOW!
would that get complicated.

Being a mechanical consulting engineer and an ex-user of CFD (Fluent software
from 1989 to 1996), I can only imagine the staggering variations in
conditions that an actual meteorite really sees as it comes through the ever-
changing atmosphere...let alone the chaotic changes that occur as a odd
looking rock begins to melt to almost nothing. Then there are the breakups
that typically occur...Good Luck modeling the real thing. We'd be better off
throwing big rocks out the window of the shuttle, and following there path
and destruction back to Earth.

If I had access to the software needed, I'd probably try to demonstrate a
couple flight scenarios. Sad to say (in some ways) I don't use it
anymore...too expensive!!! send me some software for free and I'll work on it.

Maybe someday??? someone will do something like this as part of a meteoritic
science research project using CFD and a wind tunnel.

John
IMCA 2006


> I am aware of three remotely related stories.
>
> 1. A test was conducted to replicate features on a tektite-- forming a
> tektite-like button in a blow torch stream. This resulted in a flange,
> not unlike the australites.
>
> 2. Nininger noted that from the Esterville fall there were several
> oriented "shuttlecock" shaped projectiles which he surmised was an ideal
> nose cone shape for aerodynamic stability. It was reported that he
> repeatedly submitted this to NASA who repeatedly ignored him. After
> extensive testing involving high time and cost expenses, NASA found that

> in large Harvey was right. If I recall correctly several rockets
> including the Thor carried that stubby nose cone design.
>
> 3. About 3 years ago, a (European?) return package from orbit had 3-4
> sample minerals embedded in the surface exposed to full re-entry
> heating. One of which was dolomite which would perhaps represent an
> "Earth Meteorite". Unfortunately that sample did not stay attached to
> the capsule.
>
> Obligatory ramblings--> Speaking of testing..... As to getting a test
> done, you flatter Ron and Bob. Unlike TV and Hollywood, rarely are
> tests done willy-nilly in the catagory of "to see what happens". There
> has to be a reason, a need, a scientific payoff, a researcher, facility
> time, a saftey report, yada yada yada and not least-- a budget. (See
> number 2 above) Is isn't anything like Hollywood where , 3 key strokes
> on a IBM PC will answer the most inane question a character could think

> request , such as search a world database of one-eye'd, left handed,
> chess players making the top 10 suspects appear.( One the other hand if
> you have a Macintosh and the brain power of this list..anything might be
> possible~!)
>
> Elton
>
>
> Tom aka James Knudson wrote:
>
> >Hello List, I was wondering if anyone has done hypersonic wind tunnel
> >testing on orientated meteorites?
> >
>
>
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Received on Sun 24 Aug 2003 07:42:47 PM PDT