Transcritical Phase Change in High-Pressure Spray Combustion*

The requirement of high power outputs and high efficiencies of combustion engines such as rocket engines, diesel engines and gas turbines has resulted in the increment of the system pressure close to or beyond the critical point and hence often leads to the fluids becoming supercritical in state. This has led to increased interest in both the high-pressure multicomponent phase change phenomena as well as their chemical reactions. Most existing multiphase research is concentrated on either a single- or two-component system, hence less relevant to the multicomponent phase change and reactions occurring in real engines. This work will employ our previously developed thermodynamic model based on vapor-liquid equilibrium (VLE) theory, which can predict the high-pressure phase separation near mixture critical points. This model is coupled with a reacting flow solver developed in OpenFOAM to simulate and study the effects of high-pressure phase change on transcritical combustion. An ECN Spray A type configuration is chosen to study the high-pressure phase change and combustion of fuel/oxidizer mixtures as well as differences due to different thermodynamic conditions (i.e., subcritical and supercritical).