Theoretical simulation of laser-supported absorption wave induced by millisecond multiple pulsed laser on aluminum alloy

In this paper, we established a two-dimensional spatial axisymmetric finite element model to simulate the laser-supported absorption wave(LSAW) induced millisecond multiple pulsed laser on aluminum alloy, made theoretical investigation. And the finite element analysis software, COMSOL Multiphysics, was utilized in the research. we simulated the generation and propagation procedure of LSAW based on hydrodynamic theory. All the important physical process were considered in the model which were inverse bremsstrahlung, thermal radiation, heat conduction and thermal convection. We simulated aluminum alloy irradiated by long pulse laser with 35J energy, 1ms pulse width and 1mm spot radius in the case of different pulse number, we first obtain the simulation result of velocity fields and temperature fields of LSAW, the results showed that there was a certain temperature cumulative effect near target material; Aiming at obtaining the relationship between the generation time of LSAW and laser pulse number. We keep the laser pulse width, energy density and pulse frequency unchanged, the pulse number was 3, 5, 10 respectively; the results showed that the generation time of LSAW become shorter by increasing the laser pulse number. The results of the study can be applied in the laser propulsion and laser enhancement technology, etc.