A three-dimensional numerical method for modelling weakly ionized plasmas
A three-dimensional numerical method for modelling weakly ionized plasmas
复制标题
弱电离等离子体建模的三维数值方法
DOI：
10.1111/j.1365-2966.2007.11429.x
复制
发表时间：
2006
影响因子：
4.8
通讯作者：
Turlough P. Downes
中科院分区：
文献类型：
--
作者：
Stephen O'Sullivan;Turlough P. Downes
Astrophysical fluids under the influence of magnetic fields are often subjected to single- or twofluid approximations. In the case of weakly ionized plasmas, however, this can be inappropriate due to distinct responses from the multiple constituent species to both collisional and noncollisional forces. As a result, in dense molecular clouds and protostellar accretion discs, for instance, the conductivity of the plasma may be highly anisotropic leading to phenomena such as Hall and ambipolar diffusion strongly influencing the dynamics. Diffusive processes are known to restrict the stability of conventional numerical schemes which are not implicit in nature. Furthermore, recent work establishes that a large Hall term can impose an additional severe stability limit on standard explicit schemes. Following a previous paper, which presented the one-dimensional case, we describe a fully three-dimensional method which relaxes the normal restrictions on explicit schemes for multifluid processes. This is achieved by applying the little-known Super TimeStepping technique to the symmetric (ambipolar) component of the evolution operator for the magnetic field in the local plasma rest frame, and the new Hall Diffusion Scheme to the skew-symmetric (Hall) component.
