General Solver Issues

Error: EXN-Aero cvc version( 1.380) and input CGNS file cvc version( 1.370) are incompatible!”

CGNS files contain both mesh information and custom nodes created by the EXN/Aero XML structures files. This error occurs when attempting to run EXN/Aero on a CGNS file with custom nodes created by an out-of-date version of the XML Structures.

Current XML structure file templates are included in the EXN/Aero install directory and are referenced by EXN/View.

To fix:

Import the outdated mesh file and xml structures in EXN/View, and run ‘update CGNS file’ from the File Menu. This updates the old XML structures to the latest version and overwrites outdated custom nodes in the CGNS file.


“Device real memory exceeded…/coef/mip0 185018483 > 183187236”

Memory in this context can be either host system RAM or GPU RAM;  type can be real (unpinned or pinned), double precision (unpined or pinned), integer and character.

Default memory allocation is multiplied by a user-defined factor.

To Fix:

In EXN/View, navigate the tree to the following location and increase memory allocation to a number greater than 1.0

Solver_Control >> Simulation >> Resources >> Memory_Size

“Error in creation of element neighbour list … 16005, 15000”

The CGNS format is a standard, but not all pre-processing tools export in the exact same way.  EXN/Aero is currently compatible with CGNS files exported from Pointwise, ICEM and GridPRO.

Technial support at Envenio can provide assistance with CGNS import in some circumstances. Please reach out


“Insufficient host memory. 18321465 bytes requested, 1655200 bytes free. ‘”

The simulation that the user is attempting to launch requires more memory than the system has available.

To fix:

Reduce the mesh size or deactivate models, install additional memory, or install additional GPU devices. Envenio technical support can assist in selecting appropriate hardware.


“Cannot have different quadrature levels in a multifluid DQMOM simulation….”

“Cannot have mixed buoyant flow cells in simulation….” 

“Cannot have mixed compressible/incompressible flow cells in simulation….”

“Cannot have mixed turbulent/laminar cells in simulation….”

“Cannot have mixed non-isothermal/isothermal cells in simulation….”

Some models in EXN/Aero must be activated in all fluid blocks in order to function. As noted in the error message, these include: DQMOM, Buoyant flow, compressibility, turbulence and energy transport.

To Fix:

Review all fluid blocks in the tree viewer to ensure that model settings are consistent throughout the domain


 “Stop, ill posed fine mesh size”

EXNAero caps structured mesh blocks at 1024 points in any ijk direction.

To Fix:

Subdivide mesh blocks that exceed this limit into two or more smaller blocks.


“Not found for cell coordinate in calc_database_bc…”

EXN/Aero has the ability to interpolate from user-defined field values within fluid blocks and on boundaries instead of using constant values. User-defined databases are lists of coordinates and associated field values.

This error means that some elements in the boundary or fluid block cannot find the closest point in the user-defined database.

To Fix:

Check that the coordinates in the database have a range equal to the extent of the fluid block or boundary to which the database is being applied.

In some situations it might be preferable to iincrease the search range of mesh elements. This is done by modifying the Bounding Box Extension variable in the Database branch of the tree viewer. Details on this procedure are found in the XXXXXXXXx file.


 

in Common Issues Tags: Common IssuesTroubleshooting