A theoretical study of a cutting air plasma torch

A theoretical three-dimensional axisymmetric model of the complex flow and plasma properties of cutting plasma torches have been developed. For cutting metallic plates, plasma torches must produce a narrow supersonic plasma jet with enough energy and momentum densities to melt, vaporize, and remove the metal from the impingement region. Our model allows us to study the details of the flow and to make predictions on arc voltage, heat transfer to the workpiece, force, and pressure exerted by the plasma jet on the material at the cutting zone. A good agreement is found between the model results and the available experimental data