Boiling-up of a jet of superheated water discharged through a nozzle of small diameter

An experimental investigation of the boiling-up dynamics of a jet of superheated water being discharged through a short nozzle of a small diameter ($d$ = 0.2 mm) has been conducted. A change in the shape of a boiling-up jet has been traced at various degrees of superheat. A complete flow opening has been established in the temperature range of $T$ = 493–583 K. The instability of a complete breakup has been revealed. On the basis of experimental data, the dependence of variations in the jet opening angle on the saturation pressure has been plotted in dimensionless coordinates. Low-frequency pulsations with a power spectrum inversely proportional to the frequency ($1/f$-spectrum) have been found under changes of shapes of the boiling-up flow.