Performance enhancement of ammonium dinitramide (ADN)-based thruster using coaxial dielectric barrier discharge

To enhance the performance of conventional ADN-based catalytic ignition thrusters, a plasma-assisted thruster was developed employing coaxial cylinder electrodes within a 1N-class thruster configuration. Steady-state ignition tests conducted on the experimental bench, demonstrated high repeatability in an atmospheric environment. High-speed imaging and proper orthogonal decomposition (POD) analysis revealed that plasma reduced the pulsation energy of the first mode from 84.96% to 75.21%, improving flame stability and concentrating the flame in the upstream part of the combustion chamber, without propagating toward the nozzle. Experimental evolution spectra of H2O, NH3, and CO2 were obtained through near-infrared (NIR) and midinfrared (MIR) spectrometers to probe chemical dynamics. The peak radiation intensity of H2O and NH3 in the 1.6-2.4 mu m range was observed to precede by about one second with plasma compared to the catalyst-only case. An increased radiation intensity ratio of H2O/NH3 in the presence of plasma indicated plasma's promotion of H2O production and NH3 consumption. Furthermore, the radiation intensity of CO2 increased by approximately 100-fold in the plasma-assisted case, indicating accelerated chemical reactions and more complete combustion. These findings highlight the potential of plasma-assisted technologies to improve the efficiency of ionic liquid-based thrusters and provide a foundation for future advancements in plasma-assisted propulsion systems.