SPLAT-QUENCH SOLIDIFICATION - ESTIMATING THE MAXIMUM SPREADING OF A DROPLET IMPACTING A SOLID-SURFACE

This study investigates the mechanisms that contribute to determining the maximum spreading of a liquid droplet impacting a solid surface in connection with splat-quench solidification. This paper defines two domains, the viscous dissipation domain and the surface tension domain, which are characterized by the Weber and the Reynolds numbers, and that are discriminated by the principal mechanism responsible for arresting the splat spreading. This paper illustrates the importance of correctly determining the equilibrium contact angle (a surface tension characteristic that quantifies the wetting of the substrate) for predicting the maximum spreading of the splat. Conditions under which solidification of the splat would or would not be expected to contribute to terminating the spreading of the splat are considered. However, our a priori assumption is that the effect of solidification on the spreading of a droplet, superheated at impact, is secondary compared to the effects of viscous dissipation and surface tension.