Reactive Armor

[TTK Ciar]

This topic is intended as a catch-all for discussion of reactive armors (ERA, NERA, and bulging-plate).

[TTK Ciar]

In Defence Science Journal vol5 no3, Yadav, Vohra, Joshi, Sundaram, and Kamat published "Study on Basic Mechanism of Reactive Armor":

 

http://ciar.org/ttk/mbt/armor/ads.x.era.paper.defence_science_journal.study_on_basic_mechanism_of_reactive_armor.yadav_bohra_joshi_sundaram_kamat.1995.pdf

 

On page 209, a formula is presented for the velocity of undeforming metal plates driven by a thin explosive interlayer, and all of its terms are described except for gamma. Does anyone know what gamma is supposed to describe, here? In order to get the results depicted in figure 8, it needs to be a value between 1.037 (for a 10km/s detonation velocity) and 1.033 (for a 8km/s detonation velocity).

[Guest Jason L]

Nothing detonates at 10 km/s without being super-compressed. Gamma is generally the ratio of specific heats = Cp/Cv in most gasdynamic/explosives literature.

 

Gamma is evidently variable during detonation, but the value that closest approximates detonation gasdynamics is generally a gamma of 3, convention almost always holds at 3 for anything of note I've ever seen. If you do indeed need a value of ~1.0 to make the numbers match, I'm not sure what it is then,maybe some bogus fitting parameter? His formula gives zero value added to explosive metal interactions anyway, you're far better using Gurney's symmetric sandwich expression, which requires a fit to a single well known parameter: Gurney Energy and gives excellent results which you can see from both that paper and oodles of other literature.

Edited March 31, 2012 by Jason L

[TTK Ciar]

Does anyone know where the Enigma armor modules sold to Iraq were manufactured? Uralvagonzavod? Obukhov? One of the Almaz-Antey holdings?

[bojan]

Who says they did not make them themself?