Altair nanoFluidX 2026 Release Notes

New Features

ARM platform support: nanoFluidX now supports ARM platforms, making it ready to run on NVIDIA’s Grace Superchip products.
Inlet region flow spread: Inlet regions can now create conical or triangular jet spread patterns when a spread angle and/or spread direction is specified. The spreading pattern applies to each cluster in a stencil individually. Compared to straight jets, this would facilitate a more realistic flow behavior downstream of nozzles and sprays.
Prestacking motions: Some motions now support multiple stages in a single definition. While it was possible to stack motions with individual definitions before, the process will be more seamless and less error prone when specifying all required stages in one definition.
Preview feature activation: nanoFluidX now includes a Preview Feature activation keyword for future features. This makes it easier for users to test features which are in early preview and provide feedback. Note that preview features are subject to change prior to their official release.

ParaView 6.0.x support: Python state files generated by nanoFluidX and nFX[c] now support ParaView releases between 5.9.1 and 6.0.
Improved Restart/Continue process: Certain setups were affected by restart/continue process, showing sudden change in particle movement patterns. The behavior is now improved. Restart/continue from last saved file now follows the data in restart.txt file. Contents of restart.txt file are now guaranteed to point to valid snapshots.
Inlet region fluid particle indexing and counting: Inlet region section in log now includes a table with the number of particles generated by each inlet region during the simulation time, regardless of the request for indexing the fluid particles generated by that inlet region. Inlet regions inquiring from a probe are excluded from the table and marked as “inq.”.

Definitions of polynomial temperature dependent viscosity with non-zero coefficients of second power and/or higher would lead to unexpected behavior in fluid particles. The issue has now been resolved.
The output file size had a 2GB hard limit on Windows due to implementation specifics. This limit no longer applies and files larger than 2GB can be written to disk.
Open MPI is now updated to version 5.0.8. Note that this version requires “mpiprocs” to be defined in resource requests to PBS when scheduling a nanoFluidX simulation.