Altair AcuSolve 2022.1 Release Notes


  • Gas Kinetics Model

New Features

Gas Kinetics Model
The mixture of component gases is the latest enhancement in AcuSolve’s long list of multiphase simulation capabilities. The Gas Kinetics model accounts for molecular configuration and weight, intermolecular energies, collision, and other parameters to predict the proper advection, diffusion, and blending of the various gasses. Both binary and self-diffusion are supported.


Eulerian-Eulerian Surface Tension
Fluid behavior on hydrophilic or hydrophobic surfaces can now be simulated more precisely in the Eulerian-Eulerian multiphase model with the addition of surface tension support in conjunction with contact angle model definition.
Porous Medium Effectiveness Type
The effectiveness of the resistance within a porous region may now be controlled by the local temperature of the flow within that porous region. In addition to constant values for effectiveness, piecewise_linear, cubic_spline, and user_function definitions of temperature variation may be defined.
AcuTherm Updates
AcuTherm output has been improved to support the surface point cloud output format for TAITherm via the -to csv option. The default value for thermal_layer_edge_y_plus is now 100 and AcuTherm now outputs data for laminar and solid-only simulations when film_coefficient_type is set to direct or user_ref_temp.
Topology Optimization Automatic Darcy Coefficient
The Darcy coefficient, which is utilized by the topology optimizer to identify the fluid region within the design space, can now be set to automatically adjust and update based on the simulation state. This workflow improvement removes the burden of setting this important parameter, provides faster convergence of the optimizer, and improves the final topological shape.
New HyperWorks CFD-based Tutorials
One (1) new tutorial is available in the HyperWorks CFD user interface. The new tutorial is:
  • ACU-T: 3600: Melting of Diesel Exhaust Additive within an Enclosed Tank
New SimLab-based Tutorials
Five (5) new SimLab-based tutorials are available on the SimLab Learning Center ( The new tutorials are:
  • ACU-T:3401/SL 2411 Electric Motor Analysis using AcuSolve-Flux One-Way Coupling
  • ACU-T:3600/SL 2175 Melting of Diesel Exhaust Additive within an Enclosed Tank
  • ACU-T:4300/SL 2240 Species Transport Modeling
  • ACU-T:4400/SL 2270 Y-Junction Mixing Flow using the Gas Kinetics Model
  • ACU-T:5002/SL 2302 Blower - Hybrid Motion (Rotating Frame + Sliding Mesh)
New SimLab-based Validation Cases
Five (5) new validation cases are available in the SimLab user interface. The new validation cases are:
  • Flow Inside a Rotating Cavity
  • Turbulent Flow Through a Wavy Channel
  • Laminar Flow Through a Pipe with Imposed Heat Flux
  • Laminar Poiseuille Flow Through a Pipe
  • Laminar Flow Through a Pipe with Constant Wall Temperature
Accessing Tutorial Model Files
For HyperMesh and HyperWorks CFD-based tutorials, you can now click a link, within a tutorial, to download the required model file(s) for that tutorial.
Important: This download option is only available if you (or any user) are connected to the internet. Users attempting to download a model file will be prompted with further directions on how to access the model file online. A zipped package of the model files can be downloaded from the Altair One Marketplace and extracted to a local machine or directory on your company’s local server.

Resolved Issues

  • An error which caused AcuSolve-EDEM unidirectional coupling to crash in v2022 has been fixed.
  • In AcuSflux, the solar direction definition has been corrected.
  • When AcuSolve is installed on a network drive, user functions can now be compiled on Windows platforms with AcuMakeDLL.
  • An issue where zero mass flux was reported with porous media physical velocity has been corrected.
  • Nodal output for extremely long running transients could shift the time step of output due to a precision error. This has been resolved.
  • A correction was made regarding mesh motion and multiphase flow with large density differences between fluids.
  • A description of element output statistics has been added to the Programs Reference Manual.
  • In the Command Reference Manual, the default values under REFERENCE_FRAME for centrifugal, Coriolis, and angular_acceleration are all now correctly shown to be on.
  • In HyperWorks CFD tutorials 2D plotting in AcuProbe has been replaced with the new plotting tool in the integrated post-processing workflow.
  • A minor setup change to ACU-T: 5201 has been made to define externally coupled surfaces as unconstrained.
  • A link to AcuSolve tutorials from the main help page under CFDSolversHelp has been corrected.