Investigation of the effects of alumina particle phase transition on internal flow field and engine performance in solid rocket motors.

This article focuses on developing and applying a comprehensive phase change dynamics model to analyze the effects of alumina particle phase transitions on the flow field and performance of solid rocket motor (SRM) nozzles. The model integrates stages of undercooling, nucleation, solidification, and crystal phase transformation, alongside advanced drag coefficient and heat transfer models, to simulate two-phase flow involving condensed alumina particles in nozzles with high expansion ratios. Numerical simulations reveal that particle phase changes create localized high-temperature regions, increase gas phase temperature and pressure, and enhance specific impulse, with the most significant improvement (~0.53%) occurring at a De Brouckere mean diameter (d43) of 2.63 μm and 20% particle loading. The study concludes that for high-altitude SRMs with large nozzle expansion ratios, accounting for particle phase changes is essential for accurate engine performance evaluation.