Dynamic simulation on laser-metal interaction in laser ablation propulsion considering moving interface, finite thermal wave transfer, and phase explosion.

Despite extensive investigations on the mechanism of laser-irradiated solid propellants, formulating an accurate model that characterizes more details of laser-target interactions remains a challenging task. In this paper, a thermal model for nanosecond pulsed laser ablation of aluminum was developed using the finite volume method which considers the instant recession on the propellant surface and the non-Fourier effect during heat conduction. The robust coupling iteration scheme adopted in the model tracks the dynamic boundary condition due to instant propellant removal. In particular, the pre-qualified threshold is used as discriminator for phase explosion and the thermal relaxation time is introduced to quantify the non-Fourier effect on heat conduction. In addition, the temperature-dependent physical and optical parameters of the propellant were also regarded in the proposed model. The numerical implementations for Gaussian laser ablation of aluminum were performed at different laser fluences and thermal relaxation times. The theoretical computation of the ablation depth coincides well with the experimental results to validate the feasibility of the model. • The thermal interaction of an ultra-short pulsed laser with metal was investigated. • The material moving front during heat transfer was modeled using finite volume method. • A modified critical threshold was used as a discriminator for metal phase explosion. • The thermal relaxation time was introduced to quantify the non-Fourier effect. [ABSTRACT FROM AUTHOR]