Numerical treatment of a magnetized electron fluid model in a 3D simulator of plasma thruster plumes Articles uri icon

publication date

  • October 2023

start page

  • 1

end page

  • 13

volume

  • 11, 1286345

International Standard Serial Number (ISSN)

  • 2296-424X

abstract

  • Simulations of energetic plumes from plasma thrusters are of great interest for
    estimating performances and interactions with the spacecraft. Both in fully fluid
    and hybrid (particle/fluid) models, the electron population is described by a set of
    fluid equations whose resolution by different numerical schemes can be strongly
    affected by convergence and accuracy issues. The case of magnetized plumes is
    more critical. Here, the numerical discretization of the electron fluid model of a 3D
    hybrid simulator of plasma plumes was upgraded from a finite-differences (FD)
    formulation in a collocated grid to a finite-volumes (FV) approach in a staggered
    grid. Both approaches make use of structured meshes of different resolutions and
    are compared in two scenarios of interest: 1) an unmagnetized plasma plume
    around a spacecraft and 2) a magnetized plume expansion in free space. In both
    physical scenarios, the FD scheme exhibits a global continuity error related to
    truncation errors that can be reduced only by refining the mesh. The origin of this
    error is further investigated and explained here. The FV scheme instead can save
    much computational time using coarser meshes since it is unaffected by these
    errors due to the conservativeness of its formulation. The physical advantage of
    the FV scheme over the FD approach is more evident for magnetized plumes with
    high Hall parameters since it allows us to reach higher anisotropy conditions, here
    assessed in order to gain insights into the plume magnetization effects, finding that
    the already foreseen saturation of circulating electric current occurs for Hall
    parameters of several hundreds.

subjects

  • Aeronautics
  • Mechanical Engineering
  • Physics

keywords

  • magnetized electron fluid; hybrid pic-fluid simulations; plasma plumes; finite volumes; finite differences