EFFECT OF TWO-PHASE FLOW ON THE FUEL GRAIN IGNITION AND ITS DEPARTURE FROM THE CARTRIDGE CASE

False heat targets play an important role in the safety of aircraft and helicopters. The main task is to ensure stable ignition of the fuel grain before leaving the cartridge case. In order to optimize this process, it is important to study the influence of various parameters, such as the size of the gap between the cartridge case and the cylindrical surface of fuel grain, as well as the size of the particles coming from the initiator and fuel grain. This article offers a physical and mathematical model of the ignition and departure process of the grain, and studies the influence of the specified parameters on the ignition time. The ignition times of the grain end surface for different particle sizes equals r = 1 μm and r = 25 μm have been estimated, the gap between the cartridge case and the cylindrical surface of grain ranged from 0.5 mm to 2 mm. The output velocities of the grain from the cartridge case are obtained for particles equal to 1 μm and 25 μmand different gap between the cartridge case and the cylindrical surface of fuel grain.