Error: no cartesian grid boundary condition specified

MFiX
#1

Hi,

I am trying to use the DEM method to analyse granular avalanches on a sand pile. I want to model a basic set up of a rectangular box with an inlet at the top, and a outlet on the right hand side.
I have created this geometry, but when I run the simulation I get the following error:

ERROR cartesian_grid/get_stl_data.f:674
ERROR: NO CARTESIAN GRID BOUNDARY CONDITION SPECIFIED.
AT LEAST ONE BC_TYPE MUST START WITH CG (FOR EXAMPLE CG_NSW)
RUN ABORTED

I have seen this question be asked previously on here, but I could not follow the solution. Any help is greatly appreciated.

BOX1_FACETS_IGNORED.stl (25 Bytes) Box1.mfx (9.2 KB) geometry.stl (1.5 KB)

#2

You should not use an STL file if the geometry is rectangular. All Boundary Conditions can be defined along the MFiX domain boundaries. Please see attached. I fixed a couple more issues:

  1. When defining a region, its extents must go from the lowest to highest values (Outlet y extent going from y=-0.4 to y=-0.5 is invalid)
  2. The inlet BC at the top must have a negative y-velocity (i.e. go down).

Box1.mfx (17.8 KB)

#3

Hi, thank you for your help, I have looked through your attachment and understand what you have done to correct this now.