Numerical analysis and computation of gas flows in the field of laser-based manufacturing processes
Gases are often applied in laser material processing for different tasks such as shielding the process zone from the ambient atmosphere, blowing out the molten material in case of laser cutting or air quality control in processing stations. The corresponding gas flows generally need particular attention with respect to process stability, quality control and last but not least operational costs.
The numerical analysis and computation of gas flow usually provides very reliable results. This is caused by the fact that the state behavior of gas flows is well known and can be described by the equation of state of ideal gases or gas mixtures. In addition, appropriate turbulence models for description of high-velocity gas flows are also available. As an example, Figure 1 shows the supersonic gas flow through a cutting gas nozzle in function of experimentally visualized flow fields by means of a Schlieren analysis. The results show a very good agreement regarding the positions of the characteristic shock waves.
Corresponding simulation models can be applied as helpful tools for the design and the optimization of fluidic processes and components (nozzles, processing heads, blowers, suction removals, etc.) by means of parameter studies and sensitivity analyses. Current studies involve investigations of the gas flow characteristics in laser beam fusion cutting and the air-flow optimization in laser material processing stations.