arXiv subjects

Ronghui Quan

Publications and source records attributed to Ronghui Quan.

6 recordsLinked to original sources

arXiv2026

Influence of Magnetospheric Plasma Environment on Surface Charging of the Lunar South Pole

The lunar south pole is a key candidate region for future lunar exploration and base construction, but its charging characteristics under real topographic conditions and dynamic plasma environments remain insufficiently understood. A high-fidelity terrain model of the lunar south pole spanning 86{\deg}S-90{\deg}S was constructed from optimized LRO/LOLA elevation data. Surface charging evolution over half a lunar orbital cycle was then simulated with a finite element-BP neural network scheme, using lunar-phase-dependent plasma inputs encompassing plasma parameters of solar wind and diverse Earth magnetospheric zones. The results show that south polar topography strongly regulates surface charging. Higher potentials appear on windward terrains, whereas lower potentials occur in shielded leeward regions, leading to enhanced local electric fields at the tops of uplands and crater floor-wall boundaries. Significant potential differences between the crests and the middle of the downstream walls of various craters indicate that these regions are highly terrain-sensitive. When the Moon passes through Earth's magnetosphere, surface potential and electric field are roughly symmetric around 0{\deg} lunar phase. From the solar wind to the plasma sheet, surface potential generally decreases while electric field magnitude rises. Only in the narrow magnetotail lobe adjacent to the plasma sheet does the potential temporarily increase and the electric field weaken. In the plasma sheet, the surface potential can decrease to approximately -1000 V, and the domain's peak electric field reaches about 5 V/m. These findings provide references for landing site selection, rover path planning, and electrostatic protection of lunar surface equipment.

physics.space-ph↗

arXiv2026

Mechanical Analysis of Parachute Suspension Line Deployment with Binding Tapes Using PINN

Parachutes are widely utilized in aviation, aerospace and lifesaving missions. As the initial stage of parachute deployment, suspension line extraction and straightening directly determines the smooth implementation of subsequent inflation procedures. This ultra-short process involves intricate dynamic load variations. Most existing studies adopt numerical integration of ordinary differential equations to calculate line tension, yet this method fails to rapidly acquire tension values at arbitrary positions along suspension lines. This paper develops a physics-informed neural network (PINN) algorithm for tension prediction during line extraction and straightening, which outperforms traditional integration methods in both computational efficiency and numerical accuracy. Furthermore, the regulatory law of binding tape parameters on line dynamic tension is investigated. Comparative validations against flight test data and conventional numerical results verify the reliability and effectiveness of the proposed PINN framework.

cs.LG↗

arXiv2024

Three-dimensional Simulation of Surface Charging in Meteorite Craters on Rotating Asteroids

Meteorite craters on the asteroid surface obstruct the horizontal flow of solar wind, forming a plasma wake that modulates the particle fluxes and the electrostatic environment far downstream. In this study, surface charging properties of asteroids with nontrivial terrain are simulated based on neural network and the finite element method. Key factors such as the location, size and depth-to-width ratio of craters are all considered. Under normal conditions, as the latitude of the crater increases, the potential variation at its floor during a rotation gradually becomes smoother, finally stabilizing around -3V with minor fluctuations as the crater approaches the poles. For craters with a depth-to-width ratio greater than 0.5, because of the diverging motions of electrons and the less deflected trajectories of ions, completely different charging results are observed under parallel and perpendicular solar wind incidence, the potential around the crater floor decreases and increases with the rising depth-to-width ratio, respectively. While the surface potential appears indifferent to changes in crater size, only during solar storms, the floor of large-scale craters, such as those with a diameter of 800m, perform a 9.13V decrease in potential compared to small craters of 50m. Both studies of localized plasma flow field and the surface charging phenomenon of asteroids have substantial influence on the future safe landing and exploration missions.

astro-ph.EP↗

arXiv2024

The Effect of Work Function on Dust Charging and Dynamics on the Airless Celestial Body

The charged dust on the surface of airless celestial bodies, such as the moon and asteroids, is a threat to space missions. Further research on the charged dust will contribute to the success of space missions. In this paper, we study the charging and dynamics of dust particles with different work functions. By integrating the photoelectron energy distribution function over four illuminated areas with different work functions, we evaluated the photoelectron concentration in these four areas. At each area, using the photoelectron concentration, we solve the dust charging and dynamics equations with two different gravitational acceleration values. The results reveal that the dust with a larger work function can reach higher equilibrium states. These states include dominant photoelectron-related charging currents, charge numbers, and levitation heights. We suggest that the equilibrium states all hold a clear inverse relationship with the work functions of dust particles when the solar zenith angle varies from 0 to 90 degrees, displaying consistent trends under different gravitational accelerations. We also find that dust particles seem unable to stably levitate at a critical solar zenith angle. The value of this critical SZA follows the same rule subjected to the work function.

astro-ph.EP↗

arXiv2024

Dynamic Three-dimensional Simulation of Surface Charging on Rotating Asteroids

Surface charging phenomenon of asteroids, mainly resulting from solar wind plasma and solar radiation, has been studied extensively. However, the influence of asteroid's rotation on surface charging has yet to be fully understood. Here neural network is established to replace numerical integration, improving the efficiency of dynamic three-dimensional simulation. We implement simulation of rotating asteroids and surrounding plasma environment under different conditions, including quiet solar wind and solar storms, various minerals on asteroid's surface also be considered. For asteroids with rotation periods comparable to orbital period, effect of orbital motion and obliquity also be studied. Results show that under typical solar wind, the maximum and minimum potential of asteroids will gradually decrease with their increasing periods, especially when solar wind is obliquely incident. For asteroid has period longer than one week, this decreasing trend will become extremely slow. During solar storm passing, solar wind plasma changes sharply, the susceptibility of asteroid's surface potential to rotation is greatly pronounced. Minerals on surface also count, plagioclase is the most sensitive mineral among those we explored, while ilmenite seems indifferent to changes in rotation periods. Understanding the surface charging of asteroid under various rotation periods or angles, is crucial for further research into solar wind plasma and asteroid's surface dust motion, providing a reference for safe landing exploration of asteroids.

astro-ph.EP↗

arXiv2023

Numerical simulation of a rotating magnetic sail for space applications

The Magnetic Sail is a space propulsion system that utilizes the interaction between solar wind particles and an artificial dipole magnetic field generated by a spacecraft's coil to produce thrust without the need for additional plasma or propellant. To reduce the size of the sail while improving the efficiency of capturing solar wind, a new type of rotating magnetic sail with an initial rotation speed is proposed. This study evaluates the thrust characteristics, attitude, and size design factors of a rotating magnetic sail using a 3-D single-component particle numerical simulation. The results show that an increase in rotational speed significantly increases the thrust of the rotating magnetic sail. The thrust is most significant when the magnetic moment of the sail is parallel to the direction of particle velocity. The study also found that the potential for the application of the rotating magnetic sail is greatest in orbits with high-density and low-speed space plasma environments. It suggests that a rotating magnetic sail with a magnetic moment (Mm) of 10^3-10^4 Am^2 operating at an altitude of 400 km in Low Earth Orbit (LEO) can achieve a similar thrust level to that of a rotating magnetic sail operating at 1 AU (astronomical unit) of 10^7-10^8 Am^2.

physics.app-ph↗