Liquid-Propellant Droplet Dynamics and Combustion in Supercritical Forced-Convective Environments

Abstract : A focused research has been conducted to investigate the dynamic behavior of liquid propellant droplets in supercritical forced convective environments. The purpose is to establish a solid theoretical basis for enhancing the understanding of liquid propellant droplet vaporization, combustion, and dynamics at supercritical conditions, with emphasis placed on the effect of forced convection. A variety of liquid propellants and propellant simulants, including hydrocarbon and cryogenic fluids, at both steady and oscillatory conditions were treated systematically. The formulation is based on the full conservation equations for both gas and liquid phases, and accommodates variable properties and finite rate chemical kinetics. Full account is taken of thermodynamic non-idealities and transport anomalies at high pressures, as well as liquid vapor phase equilibria for multi-component mixtures. Because the model allows for solutions from first principles, a systematic examination of droplet behavior over wide ranges of temperature and pressure is made possible. Results have not only enhanced the basic understanding of the problem, but also served as a basis for establishing droplet vaporization and combustion correlations for the study of liquid rocket engine combustion, performance, and stability.