Dynamics and microexplosion of high energy fuels injected into a combustor

The effects of microexploding fuel droplets injected into the shear layer i n an axisymmetric dump combustor are studied numerically. The fuel droplets considered are multicomponent consisting of a solid high-energy fuel core surrounded by a liquid carrier. When droplets microexplode, pressure waves are generated that reverberate through the system and in some cases couple with the characteristic frequencies of the system. In a particular case, th e low frequency quarter wave acoustic mode of the inlet is amplified, resul ting in the formation of a large vortex structure near the combustor step. Periodic energy release associated with this large vortex structure sustain s the low frequency oscillations even though droplets are injected continuo usly at a constant rate. By phase;coupling droplet injection to an external acoustic forcing frequency, it is demonstrated that pressure fluctuations at the forced frequency may be amplified or attenuated by the microexplosio n of the fuel droplets.