The experiments have been performed in subsonic flows of oxygen, nitrogen, air and carbon dioxide plasmas using 100 kW induction plasmatron IPG-4 at the IPM RAS.
The dependence of plasma temperature averaged over jet diameter versus the plasmatron operating parameters had been obtained by the absolute intensity method from radiation of 01, NI and CI spectral lines. The radial distribution of atomic temperatures have been measured and compared with the calculated ones. The discrepancy between observed and calculated radial profiles detected at high power regimes for oxygen and air plasmas are caused by neglecting radiation transfer processes in CFD modeling.
Computer code for determination of vibrational, rotational and electronic temperatures from C2 molecule spectrum parameters (Swan bands) has been developed. This code was
applied to CO2 plasma for the measurements of molecular temperatures averaged over jet diameter and their radial profiles at different operating parameters. The good agreement of observed and calculated molecular spectrum confirms the validity of applied threetemperature model. It was shown that at temperatures and gas pressures exceeding some values the emission of Swan system experiences self-absorption and this fact should be accounted in plasma temperature measurements over these molecular bands.