A phase density based enthalpy model for laser assisted phase change process

摘要

Diffusion dominated laser assisted phase change process in a pure metal is numerically investigated using the enthalpy based fixed-grid approach. The single equation based on the total enthalpy (sensible and latent heat) is used in the whole domain (solid, liquid and vapor) to describe the transport processes in individual phases. To simulate in line with the experiment for laser drilled cavity in a cylinder, density variation due to change of phase has been taken into account in the proposed axisymmetric model. The proposed model also includes temperature dependent thermal properties. An iterative enthalpy update equation is developed to capture the evolution of the complicated melt as well as vapor front. To resemble a true laser beam, a Gaussian laser pulse is irradiated on the substrate surface. The drilled cavity depth predicted using the proposed model is compared with the available experimental results and a good agreement is found.