Investigation on the steam plume shapes for sonic steam jet condensation in a vertical pipe flow

A series of experiments on sonic saturated steam injected into moving water in a vertical circular pipe were carried out. The inlet steam flow rate and the subcooled water temperature were in the range of 376~773 kg·m^-2·s^-1 and 10~55°C, respectively. Four different steam plume shapes (contraction, expansion-contraction, double expansion-contraction, and unstable jet) were typically observed. The results indicated that the steam plume shapes were significantly influenced by the Reynolds number. The maximum expansion ratio and the steam plume length increased with the decrease of Reynolds number and the condensation driving potential, and the values were lower than that of sonic steam jet condensation in stagnant water. Empirical correlation for the dimensionless steam plume length was established, and most of the measured data lay within the range of +10% and -8% of the correlation.