Evaluation of Grain Geometry on Droplet Entrainment in Liquefying Hybrid Fuels

The goal of this research is to numerically investigate the behavior of the liquid layer in hybrid rocket fuels for different grain designs. Converge, a commercial computational fluid dynamics (CFD) code, is used to simulate the flow in several different hybrid grains. Of particular interest is the effect of the grain variation on droplet entrainment, which enhances the mass flow rate and increases performance in hybrid rockets. Out of the configurations examined, the taper configurations provided the largest increase in entrainment. The center arc and plateau configuration exhibited the least amount of entrainment on a percentage basis while the remaining configurations showed only slight variations from the baseline case.