Developments in the modelling of horizontal annular two-phase flow. (26p.)

Several authors have considered the extension from vertically upward flow to horizontal flow of a model for annular two-phase flow which allows separate descriptions of liquid droplet deposition and entrainment. However, solutions to the equations which result have either not been obtained or have been found mathematically and physically unacceptable. In this paper it is shown how to obtain acceptable solutions. In addition, various physical mechanisms which could improve the model are assessed. Of these it is shown that a variable deposition flux could lead to significant improvement between theory and experiment. A model for the variable deposition flux is then developed and is shown to give results at least in qualitative agreement with known experimental results. The inclusion of the variable deposition rate in the governing equations leads to encouraging results for film thickness and film flowrate distributions.