Vented flash tubes have often been used in the ignition train of medium and large caliber weapon systems. Despite their long history of ballistic usage, there are undesirable features associated with uneven venting of the combustion products. Pressure measurements at various locations from the flash tube have shown severe variations with time, which is associated with spatially nonuniform mass discharging rate from the vent holes. Measured pressure profiles in the flash tube show counterintuitive, nonmonotonic pressure distributions with the lowest pressure in the middle of the venting section of the flash tube. A model of the flash tube venting process was developed to explain these phenomena using modern, high-order numerical schemes. Source terms accounting for mass addition from the black powder pellets, mass loss through the vent holes, wall friction, differential area changes, and volume changes from surface regression of black powder pellets were fully coupled in the model. The numerical results of this model reproduced the severe pressure variations and nonmonotonic pressure profiles observed in experiments. In general, they are caused by gas dynamic effects from a slowly moving normal shock wave in the middle portion of the venting section of the flash tube. As the driving pressure from the burning black powder pellets changes, the location of the normal shock wave jumps from one vent hole set to another, producing pressure variations observed in experiments. The physical understanding gained from this model solution has provided guidance for achieving more uniform mass discharging rate by varying the vent hole sizes as a function of distance along the flash tube.

1.
Moore
,
J. D.
,
Ferrara
,
P. J.
, and
Kuo
,
K. K.
, 2003, “
Characterization of Combustion Processes in a Windowed Flash Tube of M1020 Ignition Cartridge for 120-mm Mortar
,”
Proceedings of the 23rd International Symposium on Ballistics
, Tarrangona, Spain.
2.
Moore
,
J. D.
,
Kuo
,
K. K.
,
Acharya
,
R.
, and
Ferrara
,
P. J.
, 2009, “
Effect of Flash-Tube Vent-Hole Patters on the Combustion Product Discharge Rate
,”
International Journal of Energetic Materials and Chemical Propulsion
,
7
, pp.
199
220
.
3.
Acharya
,
R.
, and
Kuo
,
K. K.
, 2008, “
Effect of Different Flash-Tube Vent-Hole Patterns on Interior Ballistic Processes of Ignition Cartridge of 120-mm Mortar System
,”
International Journal of Energetic Materials and Chemical Propulsion
,
7
, pp.
383
398
.
4.
Porterie
,
B.
, and
Loraud
,
J. C.
, 1994, “
An Investigation of Interior Ballistics Ignition Pulse
,”
Shock Waves
0938-1287,
4
, pp.
81
93
.
5.
Gough
,
P. S.
, 2001, “
Interior Ballistic Modeling: Extensions to XKTC Code and Analytical Studies of Pressure Gradients for Lumped Parameter Codes
,” Technical Report No. ARL-CR-460, U.S. Army Research Laboratory, Aberdeen Proving Ground, MD.
6.
Nusca
,
M. J.
, and
Gough
,
P. S.
, 2001, “
Numerical Model of Multiphase Flows Applied to Solid Propellant Combustion in Gun Systems
,” Technical Report No. ARL-TR-3215, U.S. Army Research Laboratory, Aberdeen Proving Ground, MD.
7.
Brown
,
M. E.
, and
Rugunanan
,
R. A.
, 1989, “
A Temperature-Profile Study of the Combustion of Black Powder and Its Constituent Binary Mixtures
,”
Propellants, Explos., Pyrotech.
0721-3115,
14
, pp.
69
75
.
8.
White
,
K. J.
, and
Sasse
,
R. A.
, 1982, “
Relationship of Combustion Characteristics and Physical Properties of Black Powder
,” Technical Report No. ARBRL-MR-03219, U.S. Army Ballistic Research Laboratory, Aberdeen Proving Ground, MD.
9.
Lemmon
,
E. W.
,
Huber
,
M. L.
, and
McLinden
,
M. O.
, 2007,
NIST Standard Reference Database 23: Reference Fluid Thermodynamic and Transport Properties-REFPROP, Version 8.0
,
National Institute of Standards and Technology
,
Gaithersburg, MD
.
10.
Gordon
,
S.
, and
McBride
,
B. J.
, 1994, “
Computer Program for Calculation of Complex Chemical Equilibrium Compositions and Applications I. Analysis
,”
NASA
Technical Report No. 1311.
11.
Balsara
,
D. S.
, and
Shu
,
C. -W.
, 2000, “
Monotonicity Preserving Non-Oscillatory Schemes With Increasingly High Order of Accuracy
,”
J. Comput. Phys.
0021-9991,
160
, pp.
405
452
.
12.
Roe
,
P. L.
, 1981, “
Approximate Riemann Solvers, Parameter Vectors, and Difference Schemes
,”
J. Comput. Phys.
0021-9991,
43
, pp.
357
372
.
13.
Sasse
,
R. A.
, 1983, “
Strand Burn Rates of Black Powder to One Hundred Atmospheres
,” Technical Report No. BRL-TR-02490, U.S. Army Ballistic Research Laboratory, Aberdeen Proving Ground, MD.
14.
Mukunda
,
H. S.
, and
Paul
,
P. J.
, 1997, “
Universal Behaviour in Erosive Burning of Solid Propellants
,”
Combust. Flame
0010-2180,
109
, pp.
224
236
.
15.
Spiteri
,
R. J.
, and
Ruuth
,
S. J.
, 2002, “
A New Class of Optimal High-Order Strongstability-Preserving Time Discretization Methods
,”
SIAM (Soc. Ind. Appl. Math.) J. Numer. Anal.
0036-1429,
40
, pp.
469
491
.
16.
Shapiro
,
A. H.
, 1953,
The Dynamics and Thermodynamics of Compressible Fluid Flow
,
Ronald
,
New York
, Chap. 8.
17.
Chang
,
L. -M.
, 1992, “
Interior Ballistic Simulations of 25-mm Gun Charges
,” Technical Report No. BRL-TR-3330, U.S. Army Ballistic Research Laboratory, Aberdeen Proving Ground, MD.
You do not currently have access to this content.