A method of conversion of a single-phase stream into a supersonic homogenous two phase medium includes flowing the stream into an inlet section of a nozzle at an initial pressure, boiling a portion of the liquid medium by accelerating a velocity of the stream through a multistage draw-down of an inner diameter of the inlet of the nozzle to form a mixture of liquid and boiled fluid; and accelerating the mixture to a second velocity by flowing the mixture through an outlet section that diverges along the flow direction. The outlet section includes a concave portion, a convex portion, and a transition between the concave portion and the convex portion in which the concave profile smoothly transitions to the convex profile. A velocity of the stream is equal to a velocity of sound in the stream at a critical section located in the outlet section.