SimModeler

SimModeler is a model creation program from Simmetrix. It takes the mesh and geometric model and creates the input files for PHASTA.

Running

To run SimModeler, first connect via VNC, then use vglconnect to connect to one of the compute machines:

vglconnect -s viz001

Add the desired version of SimModeler to your environment (the below example will get the "default" version):

soft add +simmodeler

and lunch the GUI:

vglrun simmodeler

Converting old files

This is a guide for converting old files (parasolid and .spj) to the new format (.smd).

After connecting to one of the compute machines, add the suite of tools for SimModeler to your environment:

soft add +simmodsuite

From your case, make a new directory and copy your parasolid (.x_t or .xmt_txt), and .spj file into it. Rename the parasolid file to geom.xmt_txt and the .spj file to geom.spj, if they aren't already named that way. Then from the directory just created (now holds geom.xmt_txt and geom.spj) run:

/users/matthb2/simmodelerconvert/testConvert 

Your directory now contains two new files: model.smd and model.x_t

Creating new files

Loading in geometry is about as intuitive as is possibly can be. Go to File -> Import Geometry, browse to the appropriate model, and select Open. Once open, it is possible to both mesh the model and to create boundary conditions for it. Because BLMesher is presently the primary meshing tool, it is only necessary to use SimModeler to create boundary conditions. Go to Analysis -> Select Solver, and select phasta. After selecting phasta, the Analysis Attributes option under Analysis becomes valid. Clicking it brings up the corresponding window. From this new window, it is possible to apply boundary conditions and initial conditions by clicking the small button next to the drop down menu [add picture]. Note you must also double click on "problem definition" which will allow you to name the case. Later post processing expects the name "geom" so always name it so.

Boundary conditions

Commonly boundary conditions include:

• comp3 - Specifies a 3D velocity vector
• comp1 - Specifies a 3D vector in which the velocity is constrained. Velocity normal to this vector is not directly affected. This is useful for creating slip walls and mimicking free stream regions.
• temperature - Sets the temperature of the wall. This is only needed for compressible cases.
• scalar_1 - Sets the scalar_1 / eddy viscosity to apply at a wall. For the Spalart Allmaras models, scalar_1 should be zero at physical walls where a boundary layer develops and 3 to 5 times the molecular viscosity at free stream boundaries (http://turbmodels.larc.nasa.gov/spalart.html)
• surf ID - Associates a number with one or more faces. This can then be read by Phasta and used to apply more complicated boundary conditions in software.
• natural pressure - Apply a mean pressure over a surface. The pressure at any particular point is still allowed to vary (someone verify).
• traction vector - ??. The zero vector is typically applied at outlet.
• heat flux - Specifies the rate at which heat is injected / removed (not sure which one) into / from the fluid domain. The value is almost always set to zero to create a perfectly insulated boundary.
• scalar_1 flux - set the flux of scalar_1 / eddy viscosity into / out of the domain (not sure which one). This is typically only used at outlets where high values of eddy viscosity have been convected downstream of turbulent walls. The value is almost always set to zero.
• turbulence wall - Indicates that a surface is to be included in the calculation of d2wall files (verify) which are then used by the Spalart Allmaras turbulence model to generate more physical turbulent kinetic energy production / dissipation budgets.

Incompressible

Common BCs used for an incompressible case with the S-A turbulence model

• Initial conditions
  • initial velocity (nonzero, typically small)
  • initial scalar_1 (3-5 times free-stream molecular viscosity)
• Inflow
  • Comp 3
  • scalar_1 (also 3-5 times free-stream molecular viscosity)
• Outflow
  • natural pressure (zero)
  • scalar_1 flux (zero)
  • traction vector (zero vector)
• Solid physical walls
  • Comp 3 (zero vector)
  • scalar_1 (zero)
  • turbulence wall (value unimportant; use zero)
• Impermeable slip walls
  • Comp 1 (zero in wall-normal direction)
  • scalar_1 flux (zero)
  • traction vector (zero vector)