射频离子推力器等离子体特性的流体模拟研究

The characteristics of the inductively coupled plasma (ICP) in the discharge chamber of a radio frequency ion thruster were studied as crucial factors affecting the thruster’s performance. A two-dimensional axisymmetric fluid model was developed for the radio frequency ion thruster discharge chamber. The simulation utilized a fifth-order weighted essentially non-oscillatory (WENO) scheme and the finite difference time domain (FDTD) method to solve the flow and electromagnetic field equations, respectively. Plasma characteristics inside the self-designed 3 cm diameter thruster discharge chamber were calculated. The simulation results indicated that the coupling of axial and radial induced magnetic fields, tangential induced electric fields, and tangential induced electric currents contributed mainly to maintaining ICP in the discharge chamber. In the heating mechanism of sustaining ICP, both random heating and Ohmic heating could play significant roles, and with an increase in radio frequency power, the proportion of random heating power to total heating power also increased. By increasing the radio frequency power, the beam current and propellant utilization efficiency of the radio frequency ion thruster rose, but the electrical efficiency decreased. Increasing the propellant flow rate led to an increase in thruster beam current but a gradual decrease in propellant utilization efficiency.