Numerical modeling of spacecraft electric propulsion thrusters

There is a clear current trend towards the replacement of small chemical thrusters used for spacecraft control by electric propulsion thrusters. These thrusters use a variety of mechanisms to convert electrical power into thrust and, in general, provide superior specific impulse in comparison to chemical systems. Electric propulsion has been under development for the last 40 yr, and almost all thrusters are designed based on experience and experimentation. The present article considers the progress made in numerical simulation of electric propulsion thrusters. Due to the wide range of such devices, attention is restricted to electric propulsion thruster types that are presently in use by orbiting spacecraft. The physical regimes created in these thrusters indicate that a variety of numerical methods is required for accurate numerical simulation ranging from continuum formulations to kinetic approaches. Successes of numerical simulation models are demonstrated through specific examples. It is concluded that numerical simulations can be expected to play a more prominent role in the design and evolution of future electric propulsion thrusters.