more re-org, edits

Getting Started

===============

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=====================

MFiX-Exa is a new massively parallel code for computing multiphase

flow in which solid particles interact with the gas surrounding them.

It is built on top of AMReX, a publicly available software framework designed for building

massively parallel block-structured adaptive mesh refinement (AMR)

flow in which solid particles interact with the gas surrounding them. It is

built on top of `AMReX`_, a publicly available software framework designed for

building massively parallel block-structured adaptive mesh refinement (AMR)

applications.

MFiX-Exa relies on the same fundamental physics as in MFIX but the spatial and

MFiX-Exa relies on the same fundamental physics as in MFiX but the spatial and

time discretizations differ.  Specifically,

-  Fluid velocity is defined at cell centers; pressure is defined at nodes.

-  The advection algorithm includes an intermediate MAC projection for face-centered advection velocities

-  Incompressibility of the fluid is imposed through the use of a projection at the

   end of the time step 

-  The representation of the complex geometry includes mesh refinement around the 

   fluid-solid interface, which is represented used the embedded boundary, or

-  The advection algorithm includes an intermediate MAC projection for

   face-centered advection velocities

-  Incompressibility of the fluid is imposed through the use of a projection at

   the end of the time step

-  The representation of the complex geometry includes mesh refinement around

   the fluid-solid interface, which is represented used the embedded boundary, or

   cut-cell approach

-  Parallelization via flat MPI, OpenMP, hybrid MPI/OpenMP, or MPI/MPI.

-  Porting of MFiX-Exa to GPUs is in progress.

-  Parallel I/O using AMReX native I/O or HDF5.

-  Plotfile format supported by AmrVis, VisIt, ParaView, and yt.

MFiX-Exa is being developed at NETL and LBNL as part of the U.S. Department of Energy's

Exascale Computing Project (ECP).

MFiX-Exa heavily leverages AMReX (see https://amrex-codes.github.io/) which is also supported by 

ECP as part of the AMReX Co-Design Center.

MFiX-Exa is being developed at NETL and LBNL as part of the U.S. Department of

Energy's `Exascale Computing Project (ECP) <https://www.exascaleproject.org/>`_

MFiX-Exa heavily leverages `AMReX`_ which is also supported by ECP as part of

the AMReX Co-Design Center.

.. _AMReX: https://amrex-codes.github.io/

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   GridCreation

   DualGrid

   LoadBalancing

   grid/GridCreation

   grid/DualGrid

   grid/LoadBalancing