Study On Muzzle Flow Field In Simulated Low Pressure Environment

Environment changes a lot with the altitude and the speed when fighter flies. Aircraft gun fires in an environment of variable pressure, temperature and high speed flow. Due to the limitation of experimental conditions, previous researches of muzzle flow field mainly aimed at the ground environment. So we have insufficient understandings on the characteristics of muzzle flow field and control mechanism in high altitude environment. But aircraft gun produces great harm to the launch platform, and higher requirements are put forward in muzzle flow field control of new battle plane’s interior-type weapon. So the study on muzzle flow field in simulated high altitude environment has important significance.The experimental visualization and pressure measurement of muzzle flow field is conducted by firing a7.62-mm caliber rifle in a low pressure environment, which is simulated by a cabin. The muzzle pressure and temperature of23-mm aircraft gun is measured in atmospheric environment. The muzzle flow field of running fire is also studied through numerical simulation. It is shown that, in low pressure environment, blast wave of propellent gas flow is still the major damage source and there is power function relation between shock wave intensity and distance. With the decrease of the ambient pressure, intensity of shock wave decreases linearly and its propagation velocity increases logarithmically. Positive pressure impulse also decreases with the pressure. The muzzle flow field is more complicated under running fire. The understanding of muzzle flow field in high altitude environment is enhanced through the study, which lays the foundation for the research on muzzle flow field and its control technology of aircraft gun in real high altitude environment.