On the similarity of traditional and cluster jets during supersonic gas outflow into flooded space

Annotation. The visualization of gas flows expanding from supersonic nozzles into flooded space under the cluster formation conditions is considered. The technique of exciting the supersonic flow by a well-focused high-voltage electron beam is applied in conjunction with the scanning equipment for the gas objects. The reasons for the secondary cluster jet formation in a flow of easily condensing gases are discussed. A comparison is made between the formation of a traditional spindle-shaped jet and a secondary cluster one. The measurement results of the diameters of the traditional and cluster jets in maximum sections, obtained by the photometry method, are presented. It is shown that for the characteristic sizes of cluster jets of condensing gases, the dependence on parameters proposed by Sherman and Ashkenas is applicable in the entire range of the studied stagnation and background pressures. The similarity of the formation processes of traditional monomeric jets and secondary cluster jets under the conditions of developed condensation of the initial supersonic flow is supposed.