Download or read book Impact Velocity and Surface Temperature Effects on the Collision of a Molten Tin Droplet on a Solid Surface written by Shiraz Dean Aziz and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation was performed on the splashing and freezing of molten tin droplets on a stainless steel surface. The diameter of the droplets was 2.7 mm, and the impact velocity ranged from 1.0 m/s to 4.0 m/s. The substrate temperature was varied from 25$\sp\circ$C to 240$\sp\circ$C. Droplet impact was photographed using a 35 mm camera; both the splat diameter and liquid-solid contact angle were measured from these photographs. The substrate temperature under the impacting droplet was measured using a fast response thermocouple. The heat transfer coefficient during the first 0.5 ms of impact was obtained by matching measured surface temperature variation with an analytical solution. A simple energy conservation model was used to predict the maximum spreading of the droplet during impact. The predictions agreed well with experimental values. Instabilities were observed on the periphery of the droplet, which led to the formation of a finger pattern at velocities above 1.0 m/s. A model based on the Rayleigh-Taylor instability was used to predict the number of fingers around the periphery of the droplet.