Review of Research on Scenarios of Diffusion Combustion of Hydrogen Microjets During Their Interaction with Each Other

Abstract

   This review article presents the results of the analysis of the features of the process of diffusion combustion of hydrogen during its outflow into the air space. The article considers works devoted to the experimental study of the features of diffusion combustion of a single hydrogen microjet depending on the outflow velocity and the ignition method. The results are systematized and expressed in dimensionless Reynolds numbers. The process of diffusion combustion of hydrogen during its outflow from nozzle devices providing independent coaxial air supply is also considered. Experimentally discovered scenarios of diffusion combustion of a hydrogen microjet surrounded by an air flow are considered, and the possibility of stabilizing the process of diffusion combustion of a hydrogen microjet by a coaxial air flow flowing out of a coaxially located annular gap is shown for the first time. The discovered useful effect, which allows maintaining hydrogen combustion under the influence of a water vapor flow, is also considered. The effect of “locking” the combustion process in a narrow cone-shaped region near the nozzle exit is considered during the interaction of hydrogen flowing out of an annular nozzle with a supersonic air jet flowing out of a coaxially located micronozzle. The established conditions and features of the interaction of two single hydrogen microjets are discussed.