Optimization of the Laser Cutting Process in Relation to Maximum Cutting Speed Using Numerical Modeling
K. Kheloufi, E.H. Amara and A. Benzaoui
In the present study the maximum achievable cutting speed in relation to laser power for 1.0 mm thickness steel sheet is investigated using numerical simulation. For this purpose, a three-dimensional (3-D) transient finite volume method (FVM) model has been constructed using Fluent computational fluid dynamics (CFD) software, based on the Navier- Stokes equations and energy conservation equation for the description of momentum and heat transport phenomena, and the volume of fluid (VOF) method for free surface tracking. The Fresnel absorption model is used to handle the absorption of the incident wave by the surface of the liquid metal and the enthalpy-porosity technique is employed to account for the latent heat during melting and solidification of the material. The maximum cutting speed is defined as the speed for which the calculated cutting profile is just deep enough to cut through the workpiece thickness. It was observed that when the cutting speed is increased high enough for a given laser power level, a maximum cutting speed is reached beyond which the laser power is insufficient to produce complete cutting. The results show that maximum cutting speed increases by rising the laser power and assist gas velocity. The results indicate an intense influence of the laser power on the maximum cutting speed.
Keywords: Laser cutting, numerical simulation, computational fluid dynamics (CFD), finite volume method (FVM), maximum cutting speed, groove formation, process optimization, Navier-Stokes equations, volume of fluid (VOF) method