Theory on Deformation Behavior of a Liquid Droplet Impinging onto Hot Metal Surface

Abstract

Deformation behavior of a liquid droplet impinged on a hot metal surface is studied theoretically. For the thickness of the radial thin-film flow at the bottom part of a deforming droplet, an empirical expression is derived based on our previous experimental data, 6, 7) and the previous model11) is refined using a modified thickness expression instead of a purely theoretical formula of the thickness of the radial thin film flow. New expressions can evaluate the maximum extent of the radial spread and the time-integral of the heat-transmitting base area. Comparisons with the experimental data sustain the present theory on the deformation characteristics.
In general, the deformation behavior of a liquid droplet impinging onto a hot metal surface can be satisfactorily explained, even under extensive conditions, by this model. Previous observations6, 7) exhibiting relationship between the droplet behavior and the Weber number are also discussed in the frame work of the present study.