Cold ion flux-driven turbulence model


Simulations
===========

blob2d  - Single blob in square domain.
          No parallel dynamics
          All inputs in BOUT.inp

   $ ./gbs -d blob2d


slab2d  - Constant source flux-driven
          simulation in 2D (no parallel dynamics)
          All inputs in BOUT.inp

   $ ./gbs -d slab2d

circle2d - Axisymmetric simulation of large
           aspect-ratio circular cross-section
           tokamak. No parallel dynamics.

   $ python
   >>> import circle
   >>> circle.generate(68,1)

   $ ./gbs -d circle2d

   This generates a file circle.nc with one y point
   which for this geometry means only one point in toroidal angle.
   
   Y is parallel 
   Z is in the poloidal direction, rather than toroidal.
   
circle  - 3D turbulence simulation in large
          aspect-ratio circular cross-section
          tokamak.

   $ python
   >>> import circle
   >>> circle.generate(68,16)

   $ mpirun -np 4 ./gbs -d circle

   Output "circle.nc" has 16 points in toroidal angle
   (parallel direction).

MMS Tests
=========

