What's New
View new features for ultraFluidX 2025.1.
Altair ultraFluidX 2025.1 Release Notes
New Features
- Thermal solver
- ultraFluidX 2025.1 introduces thermal solution capabilities, featuring two thermal models: scalar transport and Boussinesq, which can be used alongside overset mesh. This release also includes three heat exchanger models—constant fluid temperature, constant coolant temperature, and constant heat release—along with a thermal wall model for facilitating heat exchange between surfaces and airflow. The thermal model enables the simulation of powertrain cooling scenarios involving multiple heat exchangers, utilizing fan-driven airflow over hot components.
Enhancements
- Coarsening of outputs
- The previous release, ultraFluidX 2025, introduced a feature that allows you to write output at a mesh resolution that is one refinement level coarser than the mesh used during the simulation, that is, combining 8 voxels into one. This feature is now extended such that data from two consecutive refinement levels can be included in the output coarsening. Writing volume data on a mesh coarsened by two refinement levels, that is, combining 4x4x4 voxels into one, can help to significantly reduce the output data size.
- Enhanced probe specification
- ultraFluidX allows you to specify probe points via coordinates for tracking data on individual points on surfaces inside the simulation domain. In order to avoid probing on unintended parts, this feature is enhanced in ultraFluidX 2025.1 to allow you to specify target parts that the probe location should ‘snap’ to. This is especially useful in complex geometries with small distances between parts, where it is difficult to identify a precise location for a surface probe.
- Overset mesh memory distribution
- Cases using overset meshes can suffer from a memory imbalance. This can be avoided by using a new feature for the area where moving and static mesh overlap, which distributes the data required in this area equally across all GPUs used in the simulation, alleviating the memory requirement which is otherwise placed on one single GPU. Note that results based on this feature may not be bitwise identical to previous results.
Resolved Issues
- Part names containing the special characters \ / : * ? “ < > | can create issues when used in a file name, in particular on a Windows system. In ultraFluidX, part names are used in output file names when coefficients or forces and moments are requested to be written individually for all parts in a simulation. This issue is resolved in ultraFluidX 2025.1 by replacing the characters mentioned above by an underscore _ when creating the respective output files for the concerned parts of the geometry.
Altair ultraFluidX 2025 Release Notes
New Features
- Introduction of additional output variables
- ultraFluidX 2025 directly outputs the standard deviation (STD) and variance of pressure enabling advanced and fast analysis of flow statistics. Additionally, you now have the option to output velocity magnitude instead of, or in addition to, the velocity components. Velocity magnitude output in place of the velocity components lead to a reduction of disk space by approximately 66 percent.
- Coarsening of outputs
- Prior to this release, displaying volumetric quantities such as 3D streamlines and iso-surfaces required large amount of disk space and significant time to post-process, particularly for transient and production level datasets. To address this, ultraFluidX 2025 allows output to be written at a coarser resolution than that used during simulation. This approach preserves the accurately of the computations while reducing output file sizes by aggregating multiple voxel values into a single, coarser voxel. Using a refinement-based strategy, one level of coarsening is available, 2x2x2. Assuming a region space discretized with a single resolution, a 2x2x2 coarsening would lead to a reduction of the output data size by approximatively 8x.
Enhancements
- Output bounding boxes
- ultraFluidX 2025 enhances output versatility by introducing bounding boxes for full output and/or selected surfaces. This feature, building on the existing functionality for partial volumes, enables you to define specific regions of interest within the flow field for more targeted data export. You can now write one or multiple subsets of volume and surface data, concentrating on the most critical areas of analysis, which improves both data relevance and storage efficiency.
- Reducing export time and memory requirements for writing H3D files
- ultraFluidX 2025 introduces an improved H3D output files algorithm resulting in significantly shorter export times. Additionally, memory usage on the calculation node for merging data across all ranks into a single file has been substantially reduced, enhancing data export performance and efficiency. These improvements are particularly beneficial for Computational Aeroacoustics (CAA) solutions, where managing large datasets is essential for accurately capturing transient and acoustic phenomena.
- Extension of the virtual fan model
- In ultraFluidX 2025, the virtual fan model, used to simulate fan effects on the flow field via a source region, has been enhanced to include the pressure loss (resistance) induced by the fan. Additionally, a new method has been introduced for modeling the tangential velocity. Alongside the existing Hough-Ordway method, you now have the option to employ a linear relation, linking circumferential speed to rotational speed and position within the fan plane. These updates provide greater flexibility and precision for modeling fan-driven airflow dynamics in complex simulations.