Advanced Grid Generation System
The 3DMAGGS code is an elliptic volume grid generator, used to generate
computational domains for Computational Fluid Dynamics (CFD) analyses of
aerodynamic vehicles. It was designed to replace the GRIDGEN3D code of the
GRIDGEN system software, reducing excessive use of supercomputer resources and
provide adequate flexibility in grid point clustering controls.
The 3DMAGGS code has been derived from the 3DGRAPE code written
by Dr. Reese L. Sorenson of NASA Ames, but has a whole host of added and
enhanced features. These include:
The code develops volume grids typically based on six defining sides of a
computational domain or block.
It is up to the user to specify the types of controls the solver is to use
or enforce for both grid line and grid point placement inside the volume grid.
As explained above, the solver has many different options and capabilities.
See Effects of 3DMAGGS Controls
or the associated
for more detail.
Thomas & Middlecoff Source Terms
- including options to use only these controls in the 3D elliptic
solver, use these source terms to initially guess the Sorenson
orthogonality source-terms, or to use them in conjuction with Sorenson
orthogonality (GRIDGEN's hybrid controls).
Optimum Grid Point Movements
based on the Ad Hoc Method presented by Dr. Ehrlich. Adapted
for fortran, this increases the rate of convergence of the 3DMAGGS
solver significantly by forcing the grid points to move as fast as
possible without inducing solver divergence.
Variable Cell Heights
specification which offers more flexibility in the specification of
the poisson solver source term for controlling grid line orthogonality
incidence with a surface.
Trans-Finite Volume Grid Initialization utilizing Dr. Bharat
Soni's blending coefficients. For multiple block decompositions, this
initialization may produce suitable volume grids that do not require
Truncation Error Limiting
for low precision (32-bit) machines, preventing the solver from diverging
due to inaccuracies in update factors to the poisson solver source terms.
This can lead to better resolved volume grids based on initial boundary
Link to GRIDGEN
enabling 3DMAGGS to be used as an alternate volume grid generator and
creating a more robust set of tools for volume grid generation.
The 3DMAGGS code is available to any citizen of the United
States of America, and the requesting organization or individual must
reside within the borders of the United States of America. To request
a Free copy of the 3DMAGGS code, contact James Godsey The
3DMAGGS code is Restricted software according to the Arms Export
Control Act (Title 22, U.S.C., Sec 2751, et seq.) and The Export
Administration Act of 1979, as amended, Title 50, U.S.C., App. 2401,
et seq. Violations of these export laws are subject to severe criminal
When you send the Usage Agreement form, please notify
Stephen J. Alter so the request may be tracked. Please address
technical questions to Mr. Alter as well.
NASA Official Responsible for Content --
Stephen J. Alter
Last Updated September 17, 2008
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