Plasma cutting is a process of metal cutting at atmospheric pressure by an arc plasma jet,
where a transferred arc is generated between a cathode and a work-piece (the metal to be
cut) acting as the anode . Small nozzle bore, extremely high
enthalpy and operation at relatively low arc current (≈ 10 ÷ 200) A are a few of the primary
features of these torches. The physics involved in such
arcs is very complicated. The conversion of electric energy into heat within small volumes
causes high temperatures and steep gradients. Dissociation, ionization, large heat
transfer rates (including losses by radiation), fluid turbulence and electromagnetic phenomena
are involved. In addition, wide variations of physical properties, such as density,
thermal conductivity, electric conductivity and viscosity have to be taken into account.
