Аннотация:A gas dynamic model of supersonic expansion of a real (supercritical) gas flow in nozzle based on the Redlich-Kwong equation of state has been developed. The proposed model can serve as a basis for describing the expansion of the main gas (carrier gas), against which processes of interest (formation of clusters, microcapsules, condensation) occur. Specific calculations were performed for clustering in Ar and Kr flow. Experimental verification of results of the model calculations of the sizes and densities of Ar and Kr clusters using the Rayleighscattering method was performed. The proposed model for describing cluster jets has been tested in the experiments aimed at creating X-ray sources and accelerated electron beams in the process of relativistic laser action on a krypton cluster jet.