Altair ultraFluidX 2022 Release Notes


  • Improved triangle splitting based on relative edge length; includes optional settings per part
  • Automatic Overset Mesh refinement corrections

New Features

Improved triangle splitting
Surface triangles of the input geometry are now split based on a maximum edge length relative to the local voxel size. The old default (splitting based on a global reference length) can be reactivated via the input deck. If necessary, the settings for the triangle splitting can also be modified on a per-part basis.
Automatic Overset Mesh refinement corrections
Multiple refinement levels inside overset mesh (OSM) regions are supported. The interface that connects the OSM to the static background mesh must be uniformly refined.
Automatic OSM refinement corrections are now available to help ensure a uniform OSM interface and, if necessary, automatically refine the mesh. The highest refinement level in the OSM interface region is used as a reference. Alternatively, the target refinement level of the interface can be manually specified. You can use this feature to automatically refine the interface, but a manual refinement is recommended to reduce the meshing time.


Improved seeding feature
The seeding functionality in ultraFluidX 2022 now has the option to read pressure fields for the seeding in addition to the velocity fields. Moreover, a non-zero fallback pressure can be specified in case that no source information is found in the input data set. The ramp-up behavior for seeded runs is also improved and further improves the convergence behavior.
Improved probe output
The default output format for probes is now scientific notation with eight significant digits. For surface probes, the output of pressure is now a default, in addition to the non-dimensional cp value.
Improved sectional aero coefficients
The sectional aero coefficient output is revised. A new file (uFX_coefficientsPerSection <X/Y/Z>_location.txt) includes the global x/y/z positions of the sections in the global reference frame. The section index is also added to the mesh preview.
Efficient alternative to mesh preview
The mesh data, written into the separate ultraFluidX mesh preview files upon request, is now also available per rank in the ultraFluidX full data files by default.
Library updates (CUDA, Open MPI, UCX)
ultraFluidX 2022 utilizes more recent versions of CUDA (version 11.4.3), Open MPI (version 4.1.2), and the Unified Communication X (UCX) framework (version 1.12.0). This does not affect the minimum required CUDA driver version (450.80.02 or higher is required).

Resolved Issues

  • Report on GPU memory consumption was based on the total amount of allocated memory on the device. Now the reported values are associated only with the current compute process.
  • Precision issues in the computation of the OSM interface location that might lead to local artifacts in the flow field are now resolved.
  • The Moment Reference System is now normalized upon solver deck reading.