Comparisons of CFD Calculations and Measurements for a Sonic Methane Plasma Jet in a Supersonic Crossflow

Extensive testing with a plasma torch operating on methane in a supersonic crossflow sparked an interest in modeling the torch using CFD to determine if methane plasma jets can be accurately modeled, and if so, to ascertain the usefulness of such results. The comparison presented here is of a methane plasma jet produced by a normally oriented plasma torch in a Mach 2.4 crossflow and the corresponding CFD model. Total temperature probing and computational calculations for a plane at 49.6 diameters downstream of the torch were the basis for comparison. In addition, shadowgraphs were compared to calculated density variations near the torch exit. CFD plots of several major species are presented as well to provide an understanding of where combustion is expected to occur in the flowfield. CFD calculations were made using GASP® (General Aerodynamic Simulation Program). Analysis of the probing and calculations shows that the CFD predicts the penetration height and shape of the centerline profile well; although there are noted areas of needed improvement to make the CFD calculations match the experimental results more closely. In addition, the CFD produced a shock profile with a bow shock angle only 2° higher than the 30° angle observed in experiments.