Static pressure and heat flux measurements of a thermal argon plasma flow in a water-cooled tube

The momentum and energy transfer phenomena with large temperature difference were investigated experimentally and theoretically, using an argon atmospheric thermal plasma. The plasma was generated by an arc discharge, 4-6 kW, and flowed into a water-cooled copper tube for static pressure measurements and into a copper block with the same size hole (8 mm i.d.) for measuring heat fluxes using a transient method. The argon flow rate was 2.77-8.31×10^-4 kg/s. The static pressure of the plasma flow shows a different variation from that of an ordinary flow and does not decrease monotonically. The axial distributions of the numerical calculations are in fair agreement with those of the experiments, and it is concluded that the contributions of recombination and of physical properties play important roles in the behavior of the confined thermal plasma flow.