The Propellant Feed System (PFS) is a crucial component of Electric Propulsion System (EPS) which is widely used in satellites for its high reliability and specific impulse. The Switching and Proportional Hybrid-controlled Xenon Feed System (SPHXFS) is a novel type of PFS with high flow regulation precision. This study develops a system-level simulation model with 75 components for the SPHXFS. The accuracy of the model is validated through the comparison with test data, showing an error of less than 3% during the startup phase and less than 0.1% after stabilization. The study analyzes the startup process and finds that the two-stage pressure reduction system avoids two-phase flow interference downstream, achieving a regulation accuracy of ±0.1%. A long-term operation simulation of the system is conducted, revealing that pressure fluctuations occur upstream at 4767 s due to Bang-Bang control. However, with proportional control adjustments, these fluctuations do not affect the flow supply. Further research examines the impact of synchronous and asynchronous control modes of the Bang-Bang Valve (TPBBV) under the tank pressures of 6–10 MPa on the system’s dynamic characteristics. It is found that the asynchronous control scheme results in a flow supply settling time that is 7.2–10 s longer than the synchronous control scheme, with an overshoot increase of 4.1%–4.9%. These insights provide valuable reference and guidance for system optimization design and the formulation of operational strategies.

The rapidly developing microsatellites have put forward new requirements of small volume and low power for propulsion systems. The Wall-Less Hall Thruster (WLHT) is proposed as a promising method to help the Hall thruster overcome the issues of wall loss and erosion when applied in microsatellites. However, the in-orbit application of WLHTs is hindered by two key issues: large beam divergence and discharge oscillations, which require further research on effective control. In this paper, a novel electromagnetic-controlled wall-less Hall thruster was developed and tested to regulate the propulsion performance including beam divergence angle, and anode oscillations. Experiments show that adjusting the coil current makes it possible to achieve high thrust performance with low anode current oscillations. According to thermalized potential theory, the performance is improved mainly due to changes in the magnetic field near the anode. At the anode voltage of 300 V and volume flow rate of 6 sccm (standard cubic centimeters per minute) using xenon gas as propellant, the electromagnetic control can increase the thrust by 10.4% (5.79 mN vs 6.39 mN) and the anode efficiency by 2.6 percentage points (19.1% vs 21.7%), and reduce the 90% plume half-angle by 14.3% (76.1° to 65.2°). In addition, the production of magnetic field via current-carrying coil can suppress the amplitude of anode current oscillations almost without reducing the thrust performance. The breathing oscillation amplitude of the anode current decreases from 37.2% to 2.6% by adjusting the coil current from +3 A to +4 A, while the thrust only decreases by 0.7% (6.39 mN vs 6.35 mN). This is mainly caused by a sudden change in the direction of the magnetic field near the cathode outlet. The performance of the proposed thruster at the anode power of 200 W is comparable to the state-of-the-art low-power wall-less Hall thrusters.

A common form of sophisticated electric propulsion technology in spacecraft is the Hall thruster. The traditional annular closed-loop Hall thrusters are unable to carry out the 2D distribution diagnosis of plasma inside the discharge channel due to structural limitations. In order to address this issue, an unclosed-loop linear channel E×B Hall thruster with optical diagnostic windows was constructed, the magnetic and flow fields inside the thruster were simulated and evaluated, and magnetic field design principles were suggested. Further, this paper verified the effective plasma confinement and electromagnetic field acceleration by the linear discharge channel configuration through steady-state discharge parameter monitoring, transient discharge oscillation analysis, plasma parameter diagnosis in the beam region, and plasma distribution structure imaging in the ionized region inside the discharge channel. The discharge mode regulation based on the discharge voltage was realized, and the evolutionary tendency of the discharge mode with the propellant flow rate was identified. Finally, this paper successfully obtained the 2D distribution fine structure of plasma inside the discharge channel on the magnetic field configuration profile. In summary, this paper realized the stable discharge and mode regulation of the plasma in the E×B field of a Hall-like thruster under a simple device, combined with the optical diagnosis of the distribution structure of the plasma in the two-dimensional plane, and put forward a new idea for the further microscopic manifestation of the typical discharge oscillation process of a Hall thruster.

This paper reports the numerical research on PPRM (pasty propellant rocket motor) through computational fluid dynamics simulation along with pipeline design comparison based on simulation results. The structure of PPRM includes feed pipelines, and the propellant is distributed in a cone shape when burnt steadily in the combustion chamber. As a result, the internal flow field presents strong 3-dimensional characteristics, which may lead to the flow instability. To accurately understand the combustion flow field and flow instability in the PPRM, a numerical simulation of the combustion chamber considering propellant pyrolysis and chemical reaction, coupled with the feed system module, is employed in the research. The effect of pipeline distribution, including the pipeline location and the nonuniformity of pipeline diameter on the internal combustion flow characteristics as well as the motor thrust, was investigated. The results show that the vortex caused by the special conical shape of the burning surface leads to pressure oscillations. By adjusting the pipeline location and the nonuniformity of pipeline diameter, the distribution of vortex varies dramatically, which leads to different oscillation frequencies and amplitude. Under some pipeline distribution schemes, there is almost no large vortex in the rocket motor, which greatly eliminates the flow acoustic coupling oscillation of the motor. The oscillation amplitude decreases from about 5.7% to less than 0.1%. The results will help guide the design of the high-performance feed system and combustion chamber of PPRM.