Abstract
This paper presents the study of a novel microwave electrothermal thruster with a dielectric resonator based approach for the plasma localization and propellant gas heating. The study is purely computational in a two-dimensional planar geometry and establishes the concept and demonstrates feasibility as an electric propulsion device. The resonant structure consists of a two cylindrical high dielectric constant (ɛr = 172.5) resonator enclosed within a plasma chamber that terminates at a convergent-divergent nozzle. The plasma chamber is irradiated by an incoming microwave that experiences a large wave electric field amplification of about 25 000 at a resonant frequency of 18.5 GHz. The field amplification results in breakdown and establishment of a steady plasma in a helium propellant in close vicinity to the nozzle. With a microwave power input of 40 W mm−1 (depth) at 1 atm. discharge pressure, the peak gas temperature is about 1300 K, with an electron number density of approximately 1020 m−3, resulting in a peak specific impulse of 245 s. The corresponding cold gas specific impulse is 150. The high specific impulse is attributed to the plasma hot zone being located in close vicinity of the nozzle, which effectively increases thrust. However, the thrust increase is accompanied by significant heat conduction losses, particularly as the dielectric gap size increases, underscoring the importance of thermal management in the system.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have