Archive for July 2008

Movement Dynamics Of Firework Shells Fired From Mortars

V. Ya. Yakovlev and S. K. Chankaev

Abstract: Experimental investigations were carried out using 125 and 310 mm firework shells. The pressures in a mortar during firing were measured. A mathematical model of the firing action concerning low pressure in the space behind the shell was developed. Here it is supposed that non-simultaneous processes of ignition and combustion of black powder particles as well as outflow of combustion materials through the gap between the shell and mortar walls limit the pressure increase. We determined the usage limit of zero-dimensional mathematical models of firing, defined kinetic characteristics for the process of flame spreading through black powder particles, analyzed the results and carried out a comparison between the calculated and experimental results of shots for firework shells of 125 and 310 mm. The calculation results were used to design 2А85 self-propelled mountings for launching shells with integral lifting charge and for the improvement of 2A30 self-propelled mountings for launching shells with integral lifting charge.

Keywords: Mathematical model, firework, ignition, combustion, flame, powder, muzzle velocity, self-propelled launcher, shell, self-propelled mounting


Ref: JPyro, Issue 27, 2008, pp23-29
(J27_23)


Download/Purchase Options :

You must be logged in to purchase or download articles.

Comparison of 6-DOF Trajectory Model with Modified Linear Theory for Bullets

Dimitrios N. Gkritzapis, Elias E. Panagiotopoulos, Dionissios P. Margaris and Dimitrios Papanikas

Abstract: A modified linear model is proposed for fast and accurate prediction of short and long-range trajectories of spin-stabilized bullets via atmospheric flight to a final impact point. This model is compared with a full 6-DOF trajectory model. The computational flight analysis takes into consideration the Mach number and total angle of attack effects by means of the variable aerodynamic coefficients.

Keywords: Low and high pitch angles, projectile trajectory, variable aerodynamic coefficients


Ref: JPyro, Issue 27, 2008, pp30-37
(J27_30)


Download/Purchase Options :

You must be logged in to purchase or download articles.