The following lists the current known limitations inside Fluent Icing.
UDF support in Fluent Icing has the following limitations:
UDFs cannot access DROP3D and ICE3D solver variables and therefore cannot influence the models contained in these modules.
Fluent workspace UDFs can still control the Fluent flow solver in Fluent Icing as long as they are inside a simulation folder.
UDFs need to be compiled by opening the Fluent workspace.
UDF source files need to be present in the simulation directory.
Linux: Fluent now uses Intel MPI 2021 by default, enabling compatibility with newer platforms. However, this newer MPI library might cause issues on older clusters (related to the UCX library version bundled by the system). On some machines, this will cause the Particles solver to suspend execution in the solver step.
Two workarounds are possible for this issue:
Use the environment variable FLUENT_INTEL_MPI_VERSION=2018 to switch to the same MPI library as used in 2022 R1. This should work on all platforms compatible with Intel MPI 2018.
Use the environment variable FI_PROVIDER=verbs to revert Intel MPI 2021 to an alternate, more compatible, communication mechanism.
Note: The FI_PROVIDER option is only applicable to clusters and cannot be used on a single machine without InfiniBand. The environment variable can either be set globally in the user account or specified in the Environment tab of the Fluent Launcher.
In some cases, Fluent might reorder the nodes inside its case file. For instance, this can happen when a case file, that contains mapped interfaces, is loaded using a different set of CPUs. Fluent Icing will now detect this change in node order and indicate to you that nodes have been reordered and that prior icing solutions are no longer compatible with the case file. If this occurs, load the case with the same number of CPUs that it was saved with.
Fluent Icing does not support the following mesh types:
Mesh with polyhedral cells, mesh with adapted (hanging nodes) cells.
Domains with a subset of cell zones disabled.
Non-matching interfaces..
Shell elements.
On Windows, network changes or power saving events might affect the connection between the Icing client and the Fluent solver. In the case of a disconnection, the session can be relaunched and the settings/results of the latest run can be loaded to restore its previous state.
The Fluent / k-omega model and Multi-shot / Settings will display (Beta) options even when beta mode is not enabled in Fluent Icing. The WJ-BSL-EARSM model is a 2 equations hybrid RSM that allows the capture of secondary flow motion driven by turbulence anisotropies or to better represent flows with strong swirl or streamline curvature. This requires prior enabling of the beta options in the Fluent Solution workspace.
Post-Analysis is a beta feature that currently includes some important limitations to be aware of:
Using Post-Analysis with Fluent solution files (.dat.h5) will display some surface variables as unavailable, and large solutions may have a long loading time.
If a calculation is paused, due to a temporary disconnection of the license server, the calculation will not automatically resume when the license server reconnects. In the case of multi-shot computations, they can be manually restarted using the Set Restart Shot option. (539807)
Multi-shot
Fluent report files are not supported when running multishot remeshing simulations. Disable these report files from your .cas[.h5] files using a Fluent Solution workspace.
Refer to the Known Limitations in Ansys Fluent 2024 R2 in the Fluent User's Guide for other issues that could affect your Fluent Icing simulation.