Abstract: Lattice Boltzmann model with double distribution function is used to study fast phase-change heat transfer in single-pulse laser metal drilling process. Flow and heat transfer of the melted metal material is considered and an immersion moving boundary scheme was used to track solid-liquid interface in the process. Pure heat conduction model and heat transfer model considering convection are used to simulate the process and the results are compared with experimental data. It shows that flow of the melted material has a great impact on phase change heat transfer during laser drilling and results with model that considers flow heat transfer are closer to experimental data. Melting rate, melting depth and temperature field distribution were analyzed, and effects of laser parameters on phase transition process were discussed. It shows that at the end of a pulse, the larger the pulse width of laser, the smaller hole depth, the larger aperture, and the lower temperature of shorter pulse laser are found.

Key words: ultrashort laser, lattic Boltzmann method, solid-liquid phase change, numerical simulation