Guidelines for Simulation CFD meshing flags for additional mesh control

Nov 1, 2014

Issue:

You would like more information on flag options that provide additional control over meshing.

Solution:

 

Mesher Flags  
mesh_enhance_off 0/1 0-use UI prescribed settings, 1-enhancement disabled
mesh_enhance_layers n n > 0 else ignored: Number of enhancement layers
mesh_enhance_thick n n > 0 else ignored; n in % (i.e 120% of nominal thickness).  The default size is 0.45 which would be a value of 45 for the flag.
mesh_boundarylayer_blend 0/1 0-blends disabled, 1-Enable (currently off)
mesh_anisotropic_blend 0/1 1-blending enabled, 0-use client prescribed setting (currently off)
mesh_BLSimplex 0/1 0-Disabled, 1-Enable (currently disabled)
mesh_multicore 0/1 0-Disabled, 1-Enable (currently disabled)
mesh_volume_autosize 0/1 0-Disabled, 1-Enable (currently disabled)


Notes:

  • Boundary Layer blend: Currently this value is off.  This flag should be used for model that contain 2D surface parts in 3D models.  The blending is helpful around sharp corners.  Without this flag you may find that the solver will diverge very late in the simulation.
  • Anisotropic blend: At the moment the transition from boundary elements to the core mesh is instantaneous – from highly anisotropic to isotropic. This can be a challenge for the isotropic mesher. Enabling this with the flag will introduce a transition in element size off the boundary layer though the transition rate is at present not something we can control.
  • mesh_BLSimplex: This will switch the wall elements from wedges to tets or simplex elements. The default setting is for wedges.  Impact is unknown.  If you find that using this flag aids your modeling please inform support.
  • mesh_multicore: This enables more CPU cores to aid in mesh models.  Hyper-threading is not used.  This flag has shown not to aid in all models.

See Also:

Older flags not available since Simulation CFD 2013. Use the options in the advanced meshing panel to control these settings.

Autosizing Flags  
automesh resolution_factor 0/1 0 factor 0-ignore, 1-use factor
automesh stretching_factor 0/1 0 factor 0-ignore, 1-use factor
automesh minimum_points 0/1 n 0-ignore, 1-use n as minimum number of points on smallest edge(s)
cfdesign autosize_scale_factor 0/1 0 factor 0-ignore, 1-use factor (0.10 < factor < 10.0)
 

Products:

Simulation CFD

Versions:

2010;2011;2012;2013;2014;2015

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