Review of investigations for various modes formation of extremely expanding cryogenic liquids jets

The review considers of investigations related to the experimental and theoretical study of formation an extremely expanding jets of cryogenic liquids when sprayed from a thin cylindrical channel into a vacuum chamber, caused by explosive boiling and pressure increase due to the avalanche growth of vapor microbubbles with the formation of fine droplets with a large opening jet angle. The relevance of such research follows from the importance of environmental protection for the safety of space exploration and is aimed at achieving reliable operation, efficiency and cost reduction of spacecraft engines using safe fuel cells such as a combination of liquid oxygen and hydrogen or methane. The importance of analyzing the distribution of fluid phases in a vacuum chamber, the diameter, concentration, and temperature of microdroplets is to determine the optimal modes that lead to successful ignition in order to intensify the rocket engine’s thrust. The scientific newness lies in the originality of the proposed approaches in the theoretical and numerical study of the designated problem based on the development of spatial models of a multiphase gas-vapor-liquid medium based on the laws of conservation of mass, momentum and energy of each phase in accordance with one- or two speeds and with two-temperature approach in a three-dimensional formulation, taking into account interfacial resistance, contact heat exchange and energy and mass exchange processes of evaporation and condensation. To describe the thermodynamic properties of the cryogenic liquid under study, it is important to construct wide-range equations of state of liquid and vapor in an analytical form. Numerical studies of the evolution of the shape and structure of an emerging vapor-liquid boiling cryogenicjet are aimed at obtaining detailed information on the problem under study and can be used as recommendations for the development of small rocket engines and devices powered by reactive thrust in a vacuum atmosphere and cryogenic temperatures.