Research on Gas Plasma Ionization Characteristics Based on Methane/Air/K2CO3 Mixed Combustion Scheme

A high-temperature gas plasma scheme using methane/air/K2CO3 mixed combustion is proposed for the application background of hypersonic aircraft. The actual combustion temperature was calculated by ANSYS Chemkin Pro software; the various components of the combustion reaction were determined; and the function between temperature and electrical conductivity was established, revealing the variation law of ionization decomposition of K2CO3 ionized seeds with gas temperature. At 1500 K, K2CO3 ionized seeds are close to complete ionization. Increasing the mass fraction of K2CO3 ionized seeds will enhance the endothermic effect of K2CO3 seed ionization decomposition. Under the same residual gas coefficient conditions, the combustion equilibrium temperature will correspondingly decrease. The increase in initial combustion temperature results in an approximately linear increase in equilibrium temperature and conductivity. With the increase in initial pressure, the equilibrium temperature of gas shows a logarithmic growth trend, while conductivity gradually decreases and the gradient of change gradually slows down. This study provides a new method for evaluating the ionization characteristics of high-temperature gas plasma formed by potassium carbonate (K2CO3) as ionization seed, and hydrocarbon fuel (CxHy) combined with air.