Numerical study on propulsion performance of solar wind magnetic sail

The three-dimensional numerical simulation of the solar wind magnetic sail was established with the magnetohydrodynamic (MHD) model considering the interplanetary magnetic field. The verification of the calculation method was accomplished by comparison with experimental data. In addition, the observation and confirmation of the magnetic reconnection were achieved at the tail of the coil. The propulsion performance of the magnetic sail was studied in terms of the incoming velocity, the plasma ion number density and the attack angle of of the solar wind. The solar wind with different velocities and different ion number densities mainly influenced the Lorentz force by affecting the current in the z direction, which further affected the propulsion performance of the magnetic sail. As incoming velocity increased from 30 km/s to 75 km/s of solar wind with fixed ion number density, the maximum current in z direction increased from 4205 A/m² to 14709 A/m², and the thrust of magnetic sail increased from 3.39 N to 13.40 N. As the ion number density increased from 1.8×10¹⁹ m⁻³ to 4.5×10¹⁹ m⁻³ of solar wind with fixed incoming velocity, the maximum current in z direction increased from 6039 A/m² to 10585 A/m², and the thrust increased from 6.62 N to 12.27 N. The variation of the attack angle affected the propulsion performance of magnetic sail by influencing the configuration of magnetic field. With the attack angle of 0° and 90°, the radius of the magnetic cavity was 0.14 m and 0.18 m, respectively. Correspondingly, the thrust of the magnetic sail was 6.62 N and 11.03 N, respectively. It was inferred that larger thrust can be obtained by keeping the axis of the coil parallel to the direction of the solar wind in practical application. The influence of relevant factors on the propulsion performance of magnetic sail was studied systematically, which can provide a reference and support for the research of thrust regulation of the sail, and has important reference value for the further study of magnetic sail.