Re: HEAT...Re: New 'electrical active' Armour to defeat hand held anti-tank rounds

I don't want to jump *between* the response that may be coming
from Oerjan on this one (that might hurt ^_- ) but I thought I
would offer this quote as a couterpoint to the Jane's reference
below:

"Detailed discussions of the shaped charge concept and an 
extensive list of sources (too numerous to list here) are 
available elsewhere, e. g., [1], [2], [3], [4]. This concept 
is not well understood by people outside the warhead community. 
For example, the jet is not a “cutting plasma”, it is not a 
liquefied or molten metal jet, the cone does not impact the
armor intact, the jet temperature is not 20,000 C, and the 
density of the jet is not several times that of steel, and the 
jet does not burn its way through armor, as reported in many
newspaper, TV, and even semi-technical journal articles."

Referencing Ryan's original question as to what material state
best describes the jet (formed from the liner) from a shaped
charge:
"The pressures generated during the liner collapse far exceed 
the yield strength of the liner material and thus the liner 
behaves approximately as an inviscid, incompressible fluid!"

These are from the introduction to "An Overview of the Shaped
Charge Concept" by William Walters, Department of Mathematical
Sciences, US Military Academy, West Point, NY.	Dunno who he is,
but he self-references a few papers or books at the end, so
presumably he's been doing this for a bit.

This article is located at:
www.dean.usma.edu/math/research/msce/11th_AUTS/papers/Walters.pdf

Hope this helps!
			  Aaron

--- rljoiner@mindspring.com wrote:
> Ryan:  You may find this a bit helpful if anyone questions the
> "plasma" again.
> From:
>
http://www4.janes.com/K2/doc.jsp?t=Q&K2DocKey=/content1/janesdata/mags/i
dr/history/dsm95/dsm00172.htm@current&QueryText=%3CAND%3E%28%3COR%3E%28%
28%5B80%5D%28HEAT+%3CAND%3E+warheads+%3CAND%3E+plasma%29+%3CIN%3E+body%2
9%2C+%28%5B100%5D%28%5B100%5D%28HEAT+%3CAND%3E+warheads+%3CAND%3E+plasma
%29+%3CIN%3E+title%29+%3CAND%3E+%28%5B100%5D%28HEAT+%3CAND%3E+warheads+%
3CAND%3E+plasma%29+%3CIN%3E+body%29%29%29%29&Prod_Name=IDR&
> 
> 
> First paragraph last 1/2, after the heading of Text:
> 
>   The 1940s saw the rapid development of High Explosive
> Anti-Tank (HEAT)
>   shaped-charge weapons, which used an explosive-backed copper
> cone to
>   melt through armour plate, using the focused energy of hot
> gas and
>   molten copper or plasma. This had a dramatic effect on
> armour
>   configurations and design, which has lasted for over 50
> years.
> 
> If Jane's isn't good enough for you, there's many other
> references out there, tell me what you consider authoritative
> and I'll supply the reference.
> 
> Although, I do have to agree with the original cut:  
>   "There is nothing "plasma-like" about the metal jet from a
> HEAT round."
> Frankly, there's nothing plasma-like.  It _IS_ plasma.
> 
> Rand.
> 
> -----Original Message-----
> From: Ryan M Gill <rmgill@mindspring.com>
> Sent: Jan 13, 2004 11:52 AM
> To: gzg-l@csua.berkeley.edu
> Cc: Oerjan Ohlson <oerjan.ohlson@telia.com>
> Subject: HEAT...Re: New 'electrical active' Armour to defeat
> hand held   anti-tank rounds
> 
> At 7:29 PM +0200 9/14/02, Oerjan Ohlson wrote:
> >
> ><sigh> There is nothing "plasma-like" about the metal jet
> from a HEAT round.
> [snip]
> [more snippage]
> 
> Ok, sorry to drag up an old conversation here. What is the jet
> from a 
> shaped charge. What material state best describes it and it's 
> characteristics?

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