Rarefied gas electro jet (RGEJ) micro-thruster for space propulsion

Abstract

This article numerically investigates a micro-thruster for small satellites which utilizes plasma actuators to heat and accelerate the flow in a micro-channel with rarefied gas in the slip flow regime. The inlet plenum condition is considered at 1 Torr with flow discharging to near vacuum conditions (<0.05 Torr). The Knudsen numbers at the inlet and exit planes are ~0.01 and ~0.1, respectively. Although several studies have been performed in micro-hallow cathode discharges at constant pressure, to our knowledge, an integrated study of the glow discharge physics and resulting fluid flow of a plasma thruster under these low pressure and low Knudsen number conditions is yet to be reported. Numerical simulations of the charge distribution due to gas ionization processes and the resulting rarefied gas flow are performed using an in-house code. The mass flow rate, thrust, specific impulse, power consumption and the thrust effectiveness of the thruster are predicted based on these results. The ionized gas is modelled using local mean energy approximation. An electrically induced body force and a thermal heating source are calculated based on the space separated charge distribution and the ion Joule heating, respectively. The rarefied gas flow with these electric force and heating source is modelled using density-based compressible flow equations with slip flow boundary conditions. The results show that a significant improvement of specific impulse can be achieved over highly optimized cold gas thrusters using the same propellant.

Kinetic modeling of polyatomic heat and mass transfer in rectangular microchannels

“…One of the very critical factors for the design of new technological devices, as well as for the improvement of existing ones, is the study of the internal gas flows in the whole range of the gas rarefaction. Some indicative examples include the vacuum industry (vacuum pumps and gas separators [1][2][3][4]), high altitude aerodynamics (mono-and bi-propellant thrusters and resistojets [5,6]) and the Micro Electronic Mechanical Systems (MEMS) industry (microresonators, comb-drive sensors and gauges [7][8][9]). More information on rarefied gas dynamics applications may be also found in [10,11].…”

Space Electroosmotic Thrusters in Ion Partitioning Soft Nanochannels

“…In the last two decades, micro/nano-spacecrafts have attracted considerable attention owing to their inherent advantages, such as decreasing launch costs, improving accuracy and efficiency, as well as dispersing space mission risks, and so on [ 1 , 2 ]. Miniaturization of space components has promoted the development of micro/nano-thrusters in the space propulsion system, where the electrokinetic propulsion technology becomes a new solution of space-related tasks [ 3 , 4 , 5 , 6 , 7 , 8 ]. Motivated by the electrokinetic electroosmosis principle, electroosmosis actuation with an external electric field is extensively applied to micro/nano-fluidics and electric machines, such as micropump devices and small thrusters, which are associated with the electric double layer (EDL) in micro/nanochannels [ 9 , 10 , 11 ].…”