Investigation of the Specifics of Steady Liquid Flow through a Submillimeter Hole under Vacuum Conditions

This paper examines the steady-state outflow of ethanol microjets in a metastable superheated state into a highly rarefied medium, accompanied by physical phenomena absent in dense gaseous environments. The formation of microjets in the form of curved, temporally and spatially unstable flows that disintegrate into droplets is reported. Flow bifurcation and explosive boiling of ethanol jets at the outlet, resulting in vapor–droplet streams, have been observed. Droplet formation on the surface of the flow source and the motion of these droplets along the surface in a direction opposite to the jet flow have also been detected, regardless of the orientation of the source in space. A mechanism explaining this reverse droplet motion is proposed.