Simulation of cooling of liquid Al–33 wt.% Cu droplet impinging on a metallic substrate and its experimental validation

In the present work a model for heat transfer during collision of a falling liquid Al–33 wt.% Cu droplet on a 304 stainless steel substrate has been developed on a FLUENT 6.3.16 platform. The model simultaneously takes into account the fluid flow and heat transfer in the liquid droplet and the surrounding gas, and the heat transfer in the substrate. The liquid–gas interface was tracked using the volume of fluid method and the contact resistance between Al–33 wt.% Cu and the substrate was taken into account. The comprehensive model correctly predicted the total spread in the droplet. As per the predicted transient thermal field, the solidification front speed oscillated along the radius of the spread droplet. Based on the estimated front speeds at these locations and Jackson–Hunt plot for Al–33 wt.% Cu, the variation of interlamellar spacing along the radial direction was found. It matched well with the variation of the experimentally measured interlamellar spacing at different locations along the radius.