Abstract: In order to obtain the launch dynamics of a new type of forest fire extinguisher for drones, the simulation software ANSYS-Workbench was used to build a forest fire-fighting bomb model for drones, and the modal change of the first six orders was discussed and analyzed. In order to ensure the safety of the projectile when it is launched, the transient dynamics of the projectile when it is launched out of the chamber was analyzed, to provide a basis for the optimal design of drone forest fire extinguishing projectile.The results showed that the tail fin of the projectile is most susceptible to deformation when the firearm is launched, and the projectile rises to the maximum equivalent stress of 94MPa at 0.62 ms during the exiting process, which is less than the allowable stress of the ABS engineering plastic. The fire extinguisher meets the emission intensity requirements under the maximum stress.

Key words: drone forest fire extinguishing projectile, launch dynamics, modal analysis, transient dynamics