What's New

View new features for nanoFluidX 2023.1.

Altair nanoFluidX 2023.1 Release Notes

Highlights

  • Continuous improvements of the vehicle wading and water management solutions.
  • Automatic vehicle positioning: Defining the front and rear vehicle wheels enables automatic positioning relative to the channel.

New Features

Suspension Model
Two suspension types are now supported for suspension model, Rigid (Double Roller 1 DOF Motion) and Linear Spring/ Damper (Double Roller 3 DOF Motion).

Enhancements

Simultaneous log display for nFX[c] as it runs together with the solver
Simultaneous log files both for nFX and nFX[c] are now available in a dual window when a simulation is launched.
Use double roller 1DoF motion in temporal frame
Both Moving Vehicle, Static Road (SLIDING frame) and Static Vehicle, Moving Road (TEMPORAL frame) can now use the same DOUBLE_ROLLER_1DOF motion definition by choosing the correct reference frame switch. This change only applies to the two assigned ROTATE_AXIS motions on the front and rear wheels of a Static Vehicle, Moving Road solution. A single DOUBLE_ROLLER_1DOF takes place of these two ROTATE_AXIS motions. With this change, the defining keyword between Moving Vehicle, Static Road and Static Vehicle, Moving Road for the motions related to the car are:
  • motions.motion.dr1dof_bod_reffrm true for Static Vehicle, Moving Road (TEMPORAL frame)
  • motions.motion.dr1dof_bod_reffrm false for Moving Vehicle, Static Road (SLIDING frame). Default behavior is set to false, so current export is not affected.
Use of binary input format for particle files
The benefit of using binary input format instead of ASCII type particle files is the smaller file size (half and one third binary particle file size compared to equivalent ASCII type particle file size). The format of binary particle file types is designed so that new formats as well as newer revisions of existing formats can be introduced (backward compatibility).
Updates to the check_nFX and system_check scripts
Now, check_nFX and system_check provide faster investigation of the potential problems which makes troubleshooting easier both for Windows and Linux operating systems.
Baffle integration into the single click SPH particle creation
The Baffle tool is now moved under the single-click particle generation menu.

Known Issues

The following issues will be addressed in a future release, as the software performance is continuously improved.
  • When using the adhesion coefficient for the SINGLE_PHASE surface tension model, the surface tension coefficient must be calibrated against experimental results or visually estimated. If you use the Tartakovsky model, the physical surface tension value is sufficient.

Resolved Issues

  • Probes bug fix – Particles were not created in the corners of selected face (due to the tolerance in the particle creation).
  • Solving nanoFluidX solution from script is now corrected.
  • Resolved issue with the export of the Outlet region geometric parameters.
  • Inconsistent angle and angular velocity treatment in xz plane in double roller 3DoF – angle and angular velocity were treated as if in a xy plane instead of a xz plane.

Altair nanoFluidX 2023 Release Notes

Highlights

  • Simplified suspension model
  • Pre and post-processing in SimLab - Further enhancements have been made to both the solver and SimLab packages to improve the user experience. This includes volumetric rendering for displaying the results, 2D plotting of variables, and revised water wading solution.

New Features

Simplified suspension model
With the newly developed 3-degrees-of-freedom double roller motion feature, you can model a simplified vehicle suspension model. This enhances the fidelity of the water wading simulations without the need for complex multi-body-dynamics coupling simulation.

Enhancements

Allow arbitrary vector for outlet region
You can now define an arbitrary vector for the outlet region orientation.
Increase precision for UTM time output
Enhanced behavior of motion transformation output.
Log file improvement
You can now show thermal conductivity and specific heat in log when activating htc_emp in surfext.

Known Issues

The following issues will be addressed in a future release, as the software performance is continuously improved.
  • When using the adhesion coefficient for the SINGLE_PHASE surface tension model, the surface tension coefficient must be calibrated against experimental results or visually estimated. If you use the Tartakovsky model, the physical surface tension value is sufficient.

Resolved Issues

  • Fixed load-balancing behavior when no fluid phase is present.
  • MotionFX can read updated UTM files to accommodate latest ParaView and nanoFluidX compatibility.
  • Fallback reference velocity calculation for planetary motion is corrected.