Investigation of flow characteristics and the condensation mechanism of ternary mixture in a supersonic nozzle

The supersonic condensation process of methane-vapor-nonane mixture was investigated in a supersonic nozzle. First, the physical model of the ternary mixture of the supersonic condensation process in a nozzle was established. Second, the mathematical model of the ternary mixture of the supersonic condensation process in a nozzle was determined based on the simulation results from a binary mixture supersonic condensation process. This work developed the flow characteristics and condensation mechanism of the ternary mixture in supersonic flows. The results indicate that when spontaneous condensation occurs, the release of latent heat causes the pressure, temperature and the Mach number to change abruptly. Condensation is still an expansion process, and after the condensation shock, water vapor began to condense spontaneously at x = 4.0 mm. The water vapor droplets served as the external nuclei of the nonane, which decreased the energy barrier of the nonane vapor, allowing it to condense at a lower super-cooling (38.3 K) and super-saturation temperature (37.4 K). It was observed that the existence of water vapor accelerated the condensation of the nonane vapor.