R. Meyer J. Köhler A. Homburg Explosives

Azides
Azides
Azide; azotures
Azides are salts of hydrazoic acid (N3H). Alkali metal azides are the
most important intermediates in the production of W Lead Azide.
Sodium azide is formed by the reaction between sodium amide
(NaNH2) and nitrous oxide (N2O). Sodium amide is prepared by introducing
gaseous ammonia into molten sodium.
Ballistic Bomb
closed vessel; ballistische Bombe; bombe pour essais ballistiques
(W Burning Rate)
The ballistic bomb (pressure bomb, manometric bomb) is used to
study the burning behavior of a W Gunpowder or W Propellant charge
powder. It consists of a pressure-resistant (dynamic loading up to
about 1000 MPa (10000 bar) hollow steel body that can be bolted
together and has a hole to adapt a piezoelectric pressure transducer.
The pressure p in the bomb is measured as a function of time t.
As a rule, studies of powder in the pressure bomb are carried out in
comparison with a powder of known ballistic performance. They are
very useful both in the development of powders and in production
monitoring.
If the dynamic liveliness L (= 1/pmax * dlnp/dt) is determined as a
function of p/pmax from the primary measured signal, then for a defined
powder geometry the parameters characterising its burn-up, the linear
burning rate ˙e (W Burning Rate) and the pressure exponent a can be
determined. Pressure bomb shots of the same powder at different
charge densities d (= mass mc of powder/volume VB of the pressure
vessel) enable the specific covolume h of the combustion gases from
the powder and the force f (powder force) of the powder to be
determined in addition. From these, if the W Heat of Explosion QEx of
the powder is known, the value of the average adiabatic coefficient æ
(= 1 + f/QEx) of the combustion gases, which is of interest for the
ballistic performance, can be derived.
Since the combustion gases of powders satisfy Abel’s equation of
state to a good approximation, it is possible by using the auxiliary
parameters (rc) density of the powder)
D : = mc/(VB * rc) ‘normalised charge density’ (1)
x : = (1 – hrc) * D/(1 – D) ‘real gas correction term’ (2)
F : = frcD/(1 – D) ‘characteristic pressure’ (3)
to write the relationship between the pressure p in the manometric
bomb and the burnt volume proportion z of the powder as
Explosives. Sixth Edition. Rudolf Meyer, Josef Köhler, Axel Homburg
Copyright © 2007 Wiley-VCH & Co. KGaA, Weinheim
ISBN: 978-3-527-31656-4
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