An investigation of interior ballistics ignition phase

Abstract

Abstract. An axisymmetric viscous two-phase model is presented which describes the transient combustion of granular propellants during the ignition phase of a ballistic charge. Details of the model are presented along with computational results for a low-pressure ballistic simulator. Predicted pressure time evolutions are compared with experimental data of a real test-firing in which an unexpected pressure excursion occurred. Gun propellant breakup effects, due to bed compaction, are taken into consideration to explain the discrepancies between the numerical and experimental results. Finally, a discussion is presented of the mechanisms by which the behavior of pressure waves can be strongly intluenced and thus controlled by the manner in which the propelling charge is ignited.

A multiphase model for compressible granular–gaseous flows: formulation and initial tests

“…High-speed, compressible, dense granular multiphase flows occur in a wide range of scenarios, including dust explosions in coal mines (Sapko et al 2000;Zheng et al 2009), grain elevators, food processing and storage facilities, volcanic eruptions (Wilson 1980), dust layers lifted by shocks (Zydak & Klemens 2007;Chuanjie et al 2012;Wayne et al 2013), dust in natural gas explosions (Liu et al 2013) and interior ballistics (Koo & Kuo 1977;Markatos & Kirkcaldy 1983;Markatos 1986;Porterie & Loraud 1994;Nussbaum et al 2006). Although these are extremely important problems, much less work has been done to formulate models that consistently cover the range from dilute to dense particle packing in the presence of high-speed gas flows and shock waves.…”

“…When the volume fraction of particles is very high, it becomes necessary to use other types of models, such as the Baer-Nunziato (BN) equations (Baer & Nunziato 1986), the Nigmatulin equations (Nigmatulin 1990) or Eulerian interior ballistic models (Koo & Kuo 1977;Markatos & Kirkcaldy 1983;Markatos 1986;Porterie & Loraud 1994;Nussbaum et al 2006). The BN equations were developed to describe high-pressure combustion processes, such as detonation of high-explosive charges, where particle compression and distortion are significant.…”

“…Interior gun ballistic models (Koo & Kuo 1977;Markatos & Kirkcaldy 1983;Markatos 1986;Porterie & Loraud 1994;Nussbaum et al 2006) involve high particle loadings, high pressures (of the order of 1000 atm or more) and high-speed flow. Particle compression and deformation can be significant under these conditions.…”

A Technique for Computing Dense Granular Compressible Flows with Shock Waves

“…Despite emphasis on low-speed flows, dense granular multiphase flows are also important when the flows are highspeed and compressible, such as those that occur in explosions [13] in coal mines, sawmills, and flour mills, volcanic eruptions [14], shock-induced lifting of dust layers [15][16][17], explosion suppression [18], and interior ballistics of guns [19][20][21][22][23]. Relatively little has been done to solve kinetic theory-based granular multiphase models suitable for the wide range of particle volume fractions and flow velocities that occur in compressible flows [15,24], which is in stark contrast to the plethora of methods for solving these equations for low-speed flows [25].…”

“…Other multiphase models for particulate flows applicable to high volume fractions include the Baer-Nunziato (BN) equations [32], the Nigmatulin equations [33], and many Eulerian interior gun ballistic models [19][20][21][22][23]. The BN equations were developed for modeling high-pressure combustion processes, such as detonation of high-explosive charges, where particle compression and distortion is significant.…”