Dynamics of a superheated surface rewetting with a falling liquid film

The results of investigating the rewetting of a surface of an overheated vertical copper heater with a falling nitrogen film are presented. The influence of the Reynolds number of the film and the initial temperature of the wall overheating on the rewetting rate and the threshold temperature is shown experimentally. The experimental data that were previously obtained by the authors showed that the rewetting front propagating on a thin-walled foil is not plane and is characterized by a cellular structure with regular boiling jets and interjet zones, where the heat transfer in the wetted zone occurs in the evaporation regime. On the basis of comparison of the experimental data, it is shown that a significant increase in the thickness of the cooled wall leads to a degeneracy of the cellular structure and the rewetting-front leveling. The experimental data are compared to the results of a numerical simulation of the rewetting process.