Research paper, 23-rd international symposium on ballistics, Tarragona, Spain 16-20 April 2007, - 8 p.
The objective of this work is theoretical modeling and numerical simulation of early phase interior ballistic processes in various parts of 120-uim mortar system by developing a 3-D mortar interior ballistic (3DMIB) code. Due to the complexity of the overall interior ballistic processes in the mortar propulsion system, it is advantageous to solve the problem in a modular fashion, i.e. simulating each component of this propulsion system separately and interfacing these modules with appropriate boundary conditions. For the tail-boom section, method of characteristics (MOC) code was developed and validated by experimental test results. For combustion processes inside the tail-boom section are compared, using two different types of pyrotechnic materials (Black powder and MRBPS) in the flash tube. The combustion event starts earlier with MRBPS pellets and shows more rapid pressurization rate. In both cases, pressure traces showed significant axial pressure wave phenomena, which were simulated reasonably close to the measured pressure-time traces. The predicted pressure in the igniter end matched very well with the experimental data that was obtained later, thus affirming the reliability of the numerical code. For the mortar tube section, the finite element method (FEM) was utilized to develop a numerical code and the calculated results are partially validated by available experimental data. For the mortar tube section, the calculated results also exhibit similar pressure wave phenomena, observed in an instrumented high-pressure combustor simulator (IHPC'S) with stationary projectile and controlled peak pressure.
Content:
Introduction.
Ignition cartridge combustion submodel and computed results.
Mortar tube combustion submodel & computed results.
Conclusions.