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

Abstract

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 mid-infrared (MIR) spectrometers to probe chemical dynamics. The peak radiation intensity of H₂O and NH₃ in the 1.6-2.4 μm 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.