Altair ultraFluidX 2024 Release Notes

New Features

Momentum Source: ultraFluidX 2024 introduces a momentum source that allows to define a volume region from which a flow with a defined velocity or mass flow originates. You can define the source region by a closed surface and a velocity or mass flow vector.
Far-Field Noise Predictions: For certain aeroacoustics applications, such as fan noise, HVAC noise and train community noise, you need to evaluate flow-induced noise levels at microphones located far-away from the turbulent regions simulated in ultraFluidX. To support this requirement, sufficient resolution must be added between the source regions and the microphones to accurately propagate acoustic waves with a minimum of dissipation. In some cases, this additional resolution leads to a significant increase of the simulation size and associated computational time. To overcome this limitation, ultraFluidX 2024 introduces a far-field noise solution based on the resolution of the Ffowcs Williams - Hawkings (FW-H) analogy. The solution consists in reconstructing the far-field noise levels at any distance from the source regions by processing transient flow information recorded in the source regions. The current capability uses input data recorded on non-rotating physical surfaces (partial surface output) or fictitious surfaces (monitoring surface output) to support the solid and porous FW-H formulations, respectively. The tool is submitted as a post-processing step after the ultraFluidX simulation. An initial implementation of this feature was released as a beta version in ultraFluidX 2023.1 and is now generally available.

Enhancements

New options for geometry input (compressed STL files and H3D format): ultraFluidX 2024 introduces two new options for geometry input. To reduce the size of the geometry input files in STL format, ultraFluidX 2024 allows to read compressed STL files directly. Supported compression formats are *.zip, *.gz, *.tgz and *.tar.gz. Moreover, ultraFluidX 2024 offers the possibility of using the H3D format for geometry input files. Reading a combined set of STL, compressed STL, and H3D files for the same calculation is also supported. To convert existing STL files into the more compact H3D format, ultraFluidX 2024 offers a command-line based conversion tool.
Greenhouse Noise (GHN) parameter presets: A default set of GHN parameters can be activated with GHN parameter presets.
New post-processing options for Overset Mesh simulations: rotating monitoring surfaces and consistent sectional coefficient output: ultraFluidX 2024 introduces two new post-processing options for overset mesh simulations: monitoring surfaces rotating with overset grid regions and consistent sectional force and moment output in overset mesh zones.; If a monitoring surface extends into an overset region, ultraFluidX 2024 will rotate the surface elements inside the overset region together with the volume mesh and write a set of outputs for this rotating monitoring surface part. Output will be supported in EnSight and H3d formats. Note that the output size can be considerably larger than for static monitoring regions, as the geometry information of the rotating monitoring surface is updated for each output step.; The second new feature is related to the ultraFluidX sectional output of aerodynamic coefficients: ultraFluidX provides the option to generate output of forces and moments per section in x, y, z of the domain, giving an overview of the contribution of each slice of the geometry to the total forces and moments. With ultraFluidX 2024, the surfaces contributing to each section are dynamically assigned, depending on the rotation of the OSM zone. Surface elements now consistently contribute to the section that they are currently located in, which renders the use of sectional coefficient output for overset mesh simulations possible.
Output of force and torque by local axis of rotation: For rotating objects, ultraFluidX 2024 introduces force and moment coefficient output relative to the axis of rotation of each corresponding instance. This is an additional default output in the folders that contain coefficient data. The feature is active for overset grid regions and for objects with a rotating boundary condition. In case that outputs for forces and moments (in SI units) or for coefficients per part are requested, the local force and torque contributions will also be exported in SI units or per part, respectively.

Resolved Issues

If a turbulence generator instance was set to using zero eddies to make it inactive, this did lead to an error in the computation. This issue has been fixed in ultraFluidX 2024.