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Paper: |
Adaptive, Lagrangian, Meshless Magnetohydrodynamics with Phurbas |
Volume: |
474, Numerical Modeling of Space Plasma Flows (ASTRONUM2012) |
Page: |
265 |
Authors: |
McNally, C. P.; Maron, J. L.; Mac Low, M.-M. |
Abstract: |
Phurbas implements an a meshless algorithm for magnetohydrodynamics with
features that are particularly useful for disks. The fields are represented
on an unstructured set of sample particles. Local, third order, least squares,
polynomial interpolations are calculated form the values of neighbouring
particles to obtain spatial derivatives of fields. Particle values and
positions are advanced in time with a second order predictor corrector scheme.
As the particles are not connected by a mesh and simply trace field values at a
point, new particles can be added and redundant ones deleted as needed to
maintain a given spatial resolution. This allows full adaptivity in the sense
that the target spatial resolution can be a function of time and space. The
scheme is stabilised with a set of dynamics artificial viscosity fields. The
particles move in a Lagrangian manner (with the fluid) so that the time step is
not limited by the bulk motion of the fluid, and each particle evolves on an
individually determined time step. We present the Phurbas algorithm and
a demonstration of a global magnetorotational instability driven turbulent disk
model, which includes the use of zoom-in high resolution regions comoving with
the flow. |
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