Distribution of liquid between flow core and a film in annular dispersed flow regime in a tube

The results of experimental investigation into the liquid flow rate in a film in the region of the dispersed annular regime of low of freon-12 are presented The liquid film has been sampled with the aid of a slot chamber. The experiments have been carried out on tubes with an inside diameter of 14.6 and 8 mm with uniform heat release along the length at pressures of 10.8-15.8 atm. abs. The mass rate being varied form 260 to 1500 kg/m2s. It is shown that the liquid flow rate in the film reduces as the vapour content increases and practically approaches zero at the place of beginning of the exchange crisis. A strong influence of the thermal flow on the distribution of the liquid between the flow kernel and the near-wall liquid film is revealed