Altair nanoFluidX 2023.1 Release Notes

• 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.

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).

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.

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.

• 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.