Changes between Version 1 and Version 2 of SelfGravity


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Timestamp:
02/22/17 12:31:24 (8 years ago)
Author:
Jonathan
Comment:

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  • SelfGravity

    v1 v2  
    1 See [wiki:"SelfGravityDevel"].
     1==== Self-Gravity ====
     2
     3AstroBEAR uses the [https://computation.llnl.gov/casc/hypre/software.html hypre] library to solve the self-gravity equations.  To use self-gravity:
     4
     51.  Look for the {{{HYPREFLAG}}} variable in {{{Makefile.inc}}} and make sure that it is set to {{{1}}}.
     62.  Set the {{{lSelfGravity}}} flag in your {{{physics.data}}} file and set it to {{{T}}}.
     7
     8Hypre will automatically initialize the potential field using the density.  The only caveat is that the initial density cannot be uniform.  When the density is uniform, hypre produces a [http://mathworld.wolfram.com/SingularMatrix.html singular matrix] that it can't solve.  Fortunately, a small density perturbation takes care of this problem without substantially affecting the dynamics of the domain.  AstroBEAR comes with a Perturbation object type that can be used for this.
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     10For more information see [wiki:"SelfGravityDevel"].