Altair ultraFluidX 2019 Release Notes

New Features

Mesh import
You can now reuse an existing discretization from a previous ultraFluidX simulation to skip the meshing step and save computational time.
Increased performance
Simulation performance has increased due to internal code restructuring and a new data structure for the wall modeling.

Enhancements

Velocity information on rotating and moving surfaces
Velocity information is now displayed on rotating and moving no-slip walls in the surface data to be able to visualize the correct setting of rotating and moving boundary conditions.
Sectional force coefficients in y- and z-direction
Force coefficient output has been enhanced with full sectional coefficients in y- and z-direction, according to a user-specified number of sections. This supersedes the previously available z-split of the force coefficient output.
Averaged mass flow included in the summary
Averaged mass flow files are now created, and report the averaged mass flow per porous medium in the simulation summary file.
Improved surface mapping at the transition of refinement levels
The method used for evaluating macroscopic data at the transition of refinement levels for the surface mapping has been improved. This yields a better representation of surface data in areas where the grid is refined near the surface of the obstacle.
Possibility to specify start iterations for all output categories
You can now specify when to start the output for each of the available output categories. This feature can be used to generate high-frequency output for a specific part of the domain or the full volume data once the initial transient phase is completed.
Selection of output variables
You can now select the field variables that should be included in the output.
Monochromatic acoustic point source
A monochromatic acoustic wave with prescribed amplitude and frequency can now be injected into the simulation.
Probe output in sub-iterations
Probe output now also is enabled in sub-time steps instead of the coarsest iteration only. This can be used to extract high-resolution results for acoustic analyses. In the same breadth, buffers in probe output and drag/lift files now are flushed in every iteration.
Improved temporal and spatial averaging in the wall modeling
Temporal and spatial averaging has been improved for the coupling of the wall model to the transient LES bulk scheme.
Write void triangles to a separate output file
Void triangles that are detected during the meshing are now stored separately in the uFX_meshData folder.
Reorganization of the output data
Altair ultraFluidX 2019 results are now stored in separate output folders for surface data, volume data, full data, and so on.
Output of memory consumption during meshing and simulation
Information on the maximum memory consumption during meshing and simulation (CPU+GPU) is now included in the Altair ultraFluidX simulation summary.
Treatment of periodic domain boundaries
Object surfaces that are intersecting with periodic domain boundary conditions are now supported.

Resolved Issues

  • The aerodynamic forces were not correctly considered on the inverted side of baffle parts.
  • If the bounding box for a section cut was not given in the input solver deck, it was initialized with (0.0, 0.0, 0.0) instead of the size of the domain bounding box.
  • The extent of turbulence regions was accidentally taken into account for the coordinates of the sectional force coefficients.
  • The averaging time scale in the wall model was scaled incorrectly.
  • The calculated projected front surface depended on the mesh setup for some cases.
  • Ramp-up failed for cases with large time steps.
  • <saved_states> parameter was ignored.