fire extinguishing bag, flight, fire-fighting aircraft, landing distribution characteristics, Engineering (General). Civil engineering (General), TA1-2040, Chemical engineering, TP155-156, Naval architecture. Shipbuilding. Marine engineering, VM1-989

In order to optimize the design of high-altitude sprinkling system of fire-fighting aircraft, it is necessary to establish a model reflecting the high-altitude spraying and distribution mechanism of mass fire extinguishing bags during the flight. Based on the discrete element method and the computational fluid dynamics method, a high-altitude spraying and distributing model of aircraft mass fire extinguishing bags is established, and the spraying characteristics and landing area distribution at different flight speeds and altitudes are obtained. The model is verified by experiments. The deviations between simulated landing distribution and experimental data are less than 20.0%. The research results provide a theoretical model for the development of aircraft high altitude fire extinguishing system, so as to significantly improve the fire extinguishing performance of aircraft spraying system.