A Generic Algorithm for Modelling Thermal Dynamics with a Moving Boundary Using COMSOL Multiphysics

J. Mi, and P. Grant
University of Oxford

Droplets spray deposition is an important materials process in which materials in the form of particulates or droplets (a mixture of liquid, semisolid and solid) are projected onto an arbitrary collecting surface and consolidate to build up a thin-layer coating or a bulk preform. Droplets depositing at the collecting surface adds new materials and inputs new thermal energy continuously onto the already consolidated materials (named preform thereafter). Tracking the evolution of the sprayed surface (the free surface) of the preform and modelling the heat flow inside the preform is a great challenge. Fundamentally, this is a problem of tracking a moving boundary coupled with a thermal dynamics simulation.

A multiphysics numerical model that captures all the important process physics of the spray forming process has been developed to simulate the spray forming process, including a submodel of shape dynamics developed, and a submodel of thermal dynamics developed using COMSOL Multiphysics to simulate the preform shape evolution and the internal heat flow.