The highest deposition of power and temperature is always near the cusp of the ATON-type Hall thruster.This shows that when there are electrons gathering at the cusp,the distribution of heat load will be uniform,which...The highest deposition of power and temperature is always near the cusp of the ATON-type Hall thruster.This shows that when there are electrons gathering at the cusp,the distribution of heat load will be uniform,which will potentially damage the reliability.Therefore,we optimize the magnetic field near the anode.We changed the magnetic field characteristics in the near-anode region with an additional magnetic screen,and performed numerical simulation with particle-incell simulation.The simulation results show that the magnetic field of the thruster with the additional magnetic screen can alleviate the over-concentration of power deposition on the anode and reduce the power deposition in the anode by 20%,while ensuring that the overall magnetic field characteristics do not change significantly.展开更多
In this paper, we summarize the research development of low-frequency oscillations in the last few decades. The findings of physical mechanism, characteristics and stabilizing methods of low-frequency oscillations are...In this paper, we summarize the research development of low-frequency oscillations in the last few decades. The findings of physical mechanism, characteristics and stabilizing methods of low-frequency oscillations are discussed. It shows that it is unreasonable and incomplete to model an ionization region separately to analyze the physical mechanism of low-frequency oscillations. Electro-dynamics as well as the formation conditions of ionization distribution play an important role in characteristics and stabilizing of low-frequency oscillations. Understanding the physical mechanism and characteristics of low- frequency oscillations thoroughly and developing a feasible method stabilizing this instability are still important research subjects.展开更多
In this study,the neutral gas distribution and steady-state discharge under different discharge channel lengths were studied via numerical simulations.The results show that the channel with a length of 22 mm has the a...In this study,the neutral gas distribution and steady-state discharge under different discharge channel lengths were studied via numerical simulations.The results show that the channel with a length of 22 mm has the advantage of comprehensive discharge performance.At this time,the magnetic field intensity at the anode surface is 10%of the peak magnetic field intensity.Further analysis shows that the high-gas-density zone moves outward due to the shortening of the channel length,which optimizes the matching between the gas flow field and the magnetic field,and thus increases the ionization rate.The outward movement of the main ionization zone also reduces the ion loss on the wall surface.Thus,the propellant utilization efficiency can reach a maximum of 96.8%.Moreover,the plasma potential in the main ionization zone will decrease with the shortening of the channel.The excessively short-channel will greatly reduce the voltage utilization efficiency.The thrust is reduced to a minimum of 46.1 m N.Meanwhile,because the anode surface is excessively close to the main ionization zone,the discharge reliability is also difficult to guarantee.It was proved that the performance of Hall thrusters can be optimized by shortening the discharge channel appropriately,and the specific design scheme of short-channel of HEP-1350 PM was defined,which serves as a reference for the optimization design of Hall thruster with large height–radius ratio.The shortchannel design also helps to reduce the thruster axial dimension,further consolidating the advantages of lightweight and large thrust-to-weight ratio of the Hall thruster with large height–radius ratio.展开更多
基金the financial support from National Natural Science Foundation of China (Nos. 51777045, 51736003)supply of the Hunan Science and Technology Innovation Project (No. 2019RS1102)supply of the Shenzhen Technology Projects (No. JCYJ20170307151117299)。
文摘The highest deposition of power and temperature is always near the cusp of the ATON-type Hall thruster.This shows that when there are electrons gathering at the cusp,the distribution of heat load will be uniform,which will potentially damage the reliability.Therefore,we optimize the magnetic field near the anode.We changed the magnetic field characteristics in the near-anode region with an additional magnetic screen,and performed numerical simulation with particle-incell simulation.The simulation results show that the magnetic field of the thruster with the additional magnetic screen can alleviate the over-concentration of power deposition on the anode and reduce the power deposition in the anode by 20%,while ensuring that the overall magnetic field characteristics do not change significantly.
基金supported by the National Natural Science Foundation of China(Grant No.51477035)the Fundamental Research Funds for the Central Universities,China(Grant No.HIT.NSRIF 2015064)the Open Research Fund Program of State Key Laboratory of Cryogenic Vacuum Technology and Physics,China(Grant No.ZDK201304)
文摘In this paper, we summarize the research development of low-frequency oscillations in the last few decades. The findings of physical mechanism, characteristics and stabilizing methods of low-frequency oscillations are discussed. It shows that it is unreasonable and incomplete to model an ionization region separately to analyze the physical mechanism of low-frequency oscillations. Electro-dynamics as well as the formation conditions of ionization distribution play an important role in characteristics and stabilizing of low-frequency oscillations. Understanding the physical mechanism and characteristics of low- frequency oscillations thoroughly and developing a feasible method stabilizing this instability are still important research subjects.
基金This work is funded by the Defense Industrial Technology Development Program(No.JCKY2019603B005)National Natural Science Foundation of China(Nos.52076054,51777045)the Hunan Science and Technology Innovation Project(No.2019RS1102).
文摘In this study,the neutral gas distribution and steady-state discharge under different discharge channel lengths were studied via numerical simulations.The results show that the channel with a length of 22 mm has the advantage of comprehensive discharge performance.At this time,the magnetic field intensity at the anode surface is 10%of the peak magnetic field intensity.Further analysis shows that the high-gas-density zone moves outward due to the shortening of the channel length,which optimizes the matching between the gas flow field and the magnetic field,and thus increases the ionization rate.The outward movement of the main ionization zone also reduces the ion loss on the wall surface.Thus,the propellant utilization efficiency can reach a maximum of 96.8%.Moreover,the plasma potential in the main ionization zone will decrease with the shortening of the channel.The excessively short-channel will greatly reduce the voltage utilization efficiency.The thrust is reduced to a minimum of 46.1 m N.Meanwhile,because the anode surface is excessively close to the main ionization zone,the discharge reliability is also difficult to guarantee.It was proved that the performance of Hall thrusters can be optimized by shortening the discharge channel appropriately,and the specific design scheme of short-channel of HEP-1350 PM was defined,which serves as a reference for the optimization design of Hall thruster with large height–radius ratio.The shortchannel design also helps to reduce the thruster axial dimension,further consolidating the advantages of lightweight and large thrust-to-weight ratio of the Hall thruster with large height–radius ratio.
