Molecular gas performance of a disk generator with swirl

Initial molecular gas performance results in a disk generator with inlet swirl are presented. Plasma properties are analyzed and compared with a chemical kinetics model of the channel flow for test conditions: stagnation temperature = 3400 K, stagnation pressure = 6.6 atm at B = 3.0 tesla for a mixture of 80% N2-20% CO2. The channel flow is characterized by chemical nonequilibrium and low interaction. The measured electron density is consistent with the results of the model, and nearly a factor of seven lower than would be predicted by assuming chemical equilibrium of the carrier gas. Nonuniformities associated with electrothermal plasma turbulence and the presence of wakes lead to a lower Hall coefficient than predicted in the rear portion of the generator. The performance results are encouraging; a peak power density of 20 MW/cu m was achieved for a radial interaction length of only 7.5 cm. Open-circuit values of E-field and Hall coefficient as high as 22 kV/m and 4, respectively, were determined.