Study of Liquid Breakup Mechanism for Application of Solid Rocket Propulsion

Aluminum-based solid fuel is widely used in solid rocket propulsion system. During combustion, the solid fuel transforms into liquid status oxidant and agglomerate into droplets which impinge to the inner wall of solid rocket motor (SRM) nozzle and result in erosion problem. When a droplet breaks up into smaller size droplet results in less inertia which has a higher chance to following the exhaust gas stream instead of impinging to the inner wall of the nozzle. In this study, the liquid breakup is achieved by changing the fluid property of surface tension. The result of a liquid breakup is obtained using computational fluid dynamics (CFD) simulation of large eddy simulations (LES) and compared with experiment. The result presents the reduction of droplet size by changing the liquid surface tension. The mechanism of droplet breakup is discussed which is found to be due to the lower Laplace pressure or droplet bounding pressure lead to the lower surface tension of the liquid.