Simulation of simultaneous tablet–emitter surface ignition by a flow of two-phase combustion products and tablet–emitter ejection from a cartridge case
Abstract:
This article presents the results of mathematical modeling of the ignition and ejection of a tablet-emitter from a cartridge case. Heat exchange between the tablet-emitter surface and combustion products is a result of the thermal conductivity of the particles, gas convection, and radiation. When the tablet surface temperature reaches the ignition temperature, the combustion products begin to move from the tablet-emitter into the free volume of the cartridge case. When the burst pressure is reached, the membrane opens and the combustion products flow out of the cartridge case. Affected by the pressure of the ejected combustion products, the tablet comes into motion and leaves the cartridge case. Time dependences of the average volume pressure in the cartridge case are obtained for two particle radii (1 and 25 $\mu$m). The ignition time for the end surface of the tablet-emitter is estimated. The gap size between the cylindrical surfaces of the tablet and the cartridge case varies from 0.5 to 2 mm. The velocity of the tablet-emitter discharge from the cartridge case is obtained. It is revealed that gap size has a significant impact on the ignition process.
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