Dynamics and microexplosion of high energy fuels injected into a combustor

The effects of microexploding fuel droplets injected into the shear layer in 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, the low frequency quarter wave acoustic mode of the inlet is amplified, resulting in the formation of a large vortex structure near the combustor step. Periodic energy release associated with this large vortex structure sustains the low frequency oscillations even though droplets are injected continuously 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 microexplosion of the fuel droplets.