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Science and Technology of Energetic Materials

Vol.72, No.3 (2011)

Research paper

Characteristics of the pressure in a mortar and the muzzle velocity of a firework shell(*in Japanese)
Dayu Ding, Masamori Higaki, Yuzo Ooki, and Tadao Yoshida
p.90-96

Abstract

Pressure produced by burned lifting charge was measured in a closed or an opened small mortar without projectile using four pressure sensors in the research. The change of pressure at the bottom of a motor, where the lifting charge is set, will instantly cause the change of pressure everywhere in the mortar because pressure propagates with speed of sound. Pressure gradient doesn't occur if the burned gas doesn't flow out, but pressure gradient occurs in the mortar otherwise. The pressure before and behind the projectile in the mortar is more complex when the burned gas flows out through the gap between projectile and mortar. Further, with measured pressure-time curve at the bottom of mortar for lifting No.3 firework shell, the pressure rise rate-time curves were calculated, and with these results the complex flow of burned gas was discussed. Finally, with measured pressure-time curves by four pressure sensors, the muzzle velocity can be calculated, and the calculation results are near the experiment results even if a lot of burned gas flows out.

> Full text (Open access*)

Keywords

firework shell, lifting charge, pressure, muzzle velocity, mortar

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