Jump to content


Photo

Oh! My God.


  • Please log in to reply
215 replies to this topic

#201 jwduquette1

jwduquette1

    Member

  • Members
  • PipPip
  • 3,018 posts
  • Gender:Male
  • Location:USA

Posted 24 May 2006 - 1420 PM

I used our (TANKNET) modified Anderson equation (I believe Paul is the one most responsible for this) with a "super-DU" modifier of 1.2.

View Post


This is the C.E. Andersen Equation for semi-infinite penetration. Two home-brewed modifications were added for scaling and back-surface effects. I think Paul had indicated that there were several folks involved with the two home-brewed modifications.

Your numbers are presumably for 0-degree obliquity? What sort of numbers would you estimate for say 68-degrees to 70-degrees? A common attack angle for alot of glacis configurations.
  • 0

#202 Guest_pfcem_*

Guest_pfcem_*
  • Guests

Posted 24 May 2006 - 1501 PM

This is the C.E. Andersen Equation for semi-infinite penetration.  Two home-brewed modifications were added for scaling and back-surface effects.  I think Paul had indicated that there were several folks involved with the two home-brewed modifications. 

View Post

Yes (with a DU modifier as the basic equation is for Tungsten penetrators). So it basically gives a ballpark estimate against "semi-infinite" RHA based on the basic physical properties of the penetrator.

Of coarse, MBT armor is not all RHA but their protection esimates are also estimated as RHAe. And we all know that different penetrator vs different armor will in reality produce results different that their respective RHAe. If we ever are able to get more than just ballpark estimated figures, then doing a separate calculation for each & every combination would be worth doing, but for now, ballpark figures for penetration & protection normalized to RHAe at least gives us values to work with.



Your numbers are presumably for 0-degree obliquity?  What sort of numbers would you estimate for say 68-degrees to 70-degrees?  A common attack angle for alot of glacis configurations.

View Post

Yes, 0-degree obliquity (straight on).

For oblique non-zero degree (straight on) hits I personally just simplify it by multiplying by the cos of the angle. It is obviously more complicated than that but we are only really able to "estimate" ballpark figures anyway.

common angles (ones I know the values of "off the top of my head")
30 degrees = 0.866
45 degrees = 0.707
60 degrees = 0.500

For glacis specifically, the RHAe estimates for the protection they provide already takes the angle into account.

Edited by pfcem, 24 May 2006 - 1523 PM.

  • 0

#203 jwduquette1

jwduquette1

    Member

  • Members
  • PipPip
  • 3,018 posts
  • Gender:Male
  • Location:USA

Posted 24 May 2006 - 2045 PM

Well there you go. The numbers are now redone for D=25mm.
  • 0

#204 Przezdzieblo

Przezdzieblo

    Member

  • Members
  • PipPip
  • 1,887 posts
  • Gender:Male
  • Location:Warsaw

Posted 13 June 2006 - 1200 PM

Just one question, based on short note in Polish "RAPORT WTO" 12/2004 (my translation, not the best but I hope you`ll catch the idea):

"At Annual AUSA Meeting 2004 there was presented the newest projectile by ATK Alliant Techsystem - new long rod 120 mm round. For better penetration at the end of rod there was installed small rocket engine, which increase projectiles muzzle velocity to 1555 m/s, what result also in increased range, flatter trajectory and faster hit. Round are already high-scale produced for US Army"

There was also small photo of round just after leaving the muzzle, with sabot discarding and `jet` flash at the end of long rod.



And now...
1555 m/s is MV of M829A3. Possible mistake of author of article who confused M829A3 w/tracer with new long rod w/rocket?
At ATK site I found no information about new tank round (MRM-KE is another round, and still tested). I remember no thread about such round with "afterburner" (or something similar to Base Bleed).
One more round in US tanks?
What do you think?
  • 0

#205 Guest_pfcem_*

Guest_pfcem_*
  • Guests

Posted 13 June 2006 - 1235 PM

Either the author is confusing the tracer for a booster rocket (more likely) or it is new APFSDS (likely based on the M829A3) that does have a rocket booster.

The US had tested rocket-assisted rounds for the A-10 GAU-8 decades ago so it is not beyong the ralm of possibility that it coulb be applied to an APFSDS.

The question is, would the added terminal velocity from such a comparatively small rocket make up for the mass lost from replacing that amount of penetrator material (DU or Tungsten). I would tend to think not.

Could you post the photo?
  • 0

#206 TRYTRY

TRYTRY

    Crew

  • Members
  • PipPip
  • 238 posts
  • Location:China

Posted 18 July 2006 - 0834 AM

What the Penetrator Material of DM53 is, WHA or other more advanced tungsten alloy?
  • 0

#207 Ssnake

Ssnake

    Virtual Shiva Beast

  • Members
  • PipPip
  • 5,157 posts
  • Gender:Male
  • Location:Hannover, Germany
  • Interests:Contemporary armor - tactics and technology

Posted 18 July 2006 - 0938 AM

Rheinmetall dubbed it "WHA IV" with the ability of adiabatic shearing.
  • 0

#208 Harkonnen

Harkonnen

    Andrei

  • Members
  • PipPip
  • 3,348 posts
  • Gender:Male
  • Location:Planet Arakkis, Dune
  • Interests:Tanks, Art, history

Posted 19 July 2006 - 1745 PM

All I can say is taht all western rounds of french, german and other origin have about the same penetration. As for the 829A3 it proved to be very inaccurate during the trials in Turkey.
  • 0

#209 EchoFiveMike

EchoFiveMike

    I offer safe passage through the wasteland

  • Members
  • PipPip
  • 11,536 posts
  • Gender:Male
  • Location:FOB Chitcago
  • Interests:Killing, killing is the solution!

Posted 19 July 2006 - 1941 PM

M829A3 isn't approved for export and was not tested in Turkey. I highly doubt it's even being issued in Iraq.

Perhaps you mean KEW-A2 which IIRC is the tungsten M829A2 analog. S/F....Ken M
  • 0

#210 EasyE

EasyE

    Junior Member

  • Members
  • PipPip
  • 257 posts
  • Gender:Male
  • Location:Halifax
  • Interests:Hockey,Tanks

Posted 23 July 2006 - 1226 PM

Why would the Americans try and sell a round to the Turks that they know would be hopelessly inaccurate? That is not something that can be swept under the rug in trials.
  • 0

#211 Paul Lakowski

Paul Lakowski

    Man of the worldly means

  • Members
  • PipPip
  • 3,718 posts
  • Gender:Male
  • Interests:Armor Tech and silly humor.

Posted 23 July 2006 - 1256 PM

Why would the Americans try and sell a round to the Turks that they know would be hopelessly inaccurate? That is not something that can be swept under the rug in trials.

View Post



Don't take such comments too seriously. Until we actually see test results that we can all reference too its just more useless rumor mill material. Even commentary is irrelevant.

Now knowing that the DM-53 uses '"WHA IV" with the ability of adiabatic shearing', is useful . But we don't know how much better such alloy does than the WHA alloy they use. We could tentatively give it the same performance bounce as DU alloy does. However thats a tentative assumption for now.
  • 0

#212 Djuice

Djuice

    Crew

  • Members
  • PipPip
  • 791 posts

Posted 18 August 2006 - 1105 AM

So how about some estimates on Modern 125mm APFSDS?

eg: Tapna, Pronit, Mango, Svinet.. ...
  • 0

#213 Przezdzieblo

Przezdzieblo

    Member

  • Members
  • PipPip
  • 1,887 posts
  • Gender:Male
  • Location:Warsaw

Posted 18 August 2006 - 1130 AM

So how about some estimates on Modern 125mm APFSDS?

eg: Tapna, Pronit, Mango, Svinet.. ...

View Post



Czech 125/EPpSv-97
(by 05 Explosia Pardubice-Semtima, penetrators probably by IMI)
500 mm RHAe/2000 m
Posted Image - this one??
http://www.army.cz/s...ail.php?id=6539

Polish 125 mm APFSDS
(Developed by WITU, made by ZPS Pionki (former Pronit) with cooperation FPS Bolechowo)
500 mm RHAe/2000 m
Posted Image
http://www.bumar.com...nk_Gun_2A46.pdf


I guess 500 mm RHAe/2000 m is certified penetration.

Edited by Przezdzieblo, 18 August 2006 - 1131 AM.

  • 0

#214 Guest_pfcem_*

Guest_pfcem_*
  • Guests

Posted 30 August 2006 - 2300 PM

Another thought on the possible penetrator length of the M829A3 penetrator.

The M829A1 projectile is 780mm long & the penetrator is 684mm long. If the M829A3 penetrator is the same 96mm shorter then it would be 828mm (924-96) long! Without going back through the posts, I believe someone had indicated that it could be as much as 830mm long.

A 828mm x 25mm penetrator would calculate to [email protected] RHAe penetration (vs 750mm for a 800mm long penetrator).
  • 0

#215 TRYTRY

TRYTRY

    Crew

  • Members
  • PipPip
  • 238 posts
  • Location:China

Posted 31 August 2006 - 2255 PM

LOSAT pic from Army S&T Overview .... Objective Force Munitions (NDIA 2001 Munitions Executive Summit, 13 February 2001) by Dr. A. Michael Andrews, Deputy Assistant Secretary of the Army, Research and Technology / Chief Scientist.
I estimate the Penetrator Length is 950-1000mm, the Penetrator Diameter is 30-35mm, so Penetration is 40-44inch.

Attached Files


  • 0

#216 TTK Ciar

TTK Ciar

    Member

  • Members
  • PipPip
  • 1,742 posts
  • Gender:Male
  • Location:Sebastopol, CA, USA
  • Interests:material engineering, composite armor, GPC, battletank technology

Posted 09 January 2018 - 1733 PM

Please pardon the topic necromancy :-)

I had reason to revisit the part of this thread where folks were helping me sort out the implementation of Anderson's penetration formula, and it occurred to me that it might interest some to review the collection of ballistic formula implementations (including Anderson) I submitted to CPAN last year:

https://metacpan.org...ics::Ballistics

Some of these are definitely works in progress and leave something to be desired.

Edited by TTK Ciar, 09 January 2018 - 1734 PM.

  • 0




1 user(s) are reading this topic

0 members, 1 guests, 0 anonymous users