Altair AcuSolve 2021 Release Notes

New Features

Compressible Flow
AcuSolve now delivers the ability for users to simulate subsonic, transonic, and supersonic flows. Speeds of up to Mach 1.5, including shocks and expansions, are solved with minimal Courant-Friedrichs-Lewy (CFL) constraints using the compressible Navier-Stokes equations option. Compressible flow is compatible with all currently available single-phase features including turbulence models and mesh motion. The Sutherland viscosity and conductivity material models have been added as well. Nodal output data for compressible flow include density and Mach number. Total pressure and total temperature are added to Derived Quantity output.
EDEM 2-way Coupling
AcuSolve multiphysics capabilities are extended with the addition of bi-directional coupling with EDEM. Currently, users can couple EDEM and AcuSolve through sequential steady, sequential transient, and now full two-way transient coupling. Additionally, particles much larger than the mesh size are permitted. Heat transfer is now supported for particle-particle, fluid-particle, and solid-particle interactions and all mesh motion functionality can be used in EDEM-coupled runs.
Multiphase Improvements
Contact angle calculations now provide additional accuracy of liquid free surfaces in immiscible multiphase calculations and the behavior of liquid droplets on hydrophilic or hydrophobic solid surfaces can be modeled as well.
GPU Acceleration
The temperature_flow equation is now supported on GPU.
Altair Compute Console
The Altair Compute Console (ACC) is the easiest way to launch an AcuSolve simulation. It includes an interactive GUI for selecting input files, defining run options, submitting multiple solver runs using a queue, scheduling a delay, stopping a job, and has all the environment variables needed to run AcuSolve predefined. ACC help can be launched from within the software as well.


Evaporation mass flux
Quantify the condensation and evaporation of water vapor on a surface when using the humid air model. The integrated value of field_flux for Humid Air provides the rate of mass transfer to or from a surface in units of mass/time. A positive value indicates condensation and a negative value indicates evaporation.
Carreau-Yasuda viscosity model
The temperature-dependent Carreau-Yasuda viscosity model is now available.
Total temperature
Total temperature is now available for the OSI, OEI, OSS, and OES output types.
Radiation output
Two new variables, radiative_heat_flux (OSF) and surface_radiative_heat_flux (OSI), have been added for the discrete ordinate radiation model. These variables allow the user to quantify the contribution of radiation heat transfer on a surface.
Backflow reported
Reversed flow at inlets and outlets is now quantified and reported to the user in the Log file at runtime.
Utility programs
The AcuLiftDrag and AcuGetCpCf utilities now accept wild cards when specifying surface names. The AcuInterp and AcuPlotData utilities are now available on the Windows platform.
Tutorial Additions
New SimLab tutorials have been added for the Heat Exchanger Component (ACU3300/SL2150) and the Rigid Body Check Valve (ACU5200/SL2330).
New HyperWorks CFD tutorials have been added for Supersonic Converging-Diverging Nozzle (ACU2400), Sequential Transient Coupling with EDEM (ACU6101), Bi-Directional Coupling with EDEM (ACU6102), and Contact Angle (ACU4003).
Existing tutorials for Porous Media (ACU6010), Humidity (ACU4200), Condensation/Evaporation (ACU4201), DO (ACU3203) and P1 (ACU3202) Radiation, and Sliding Mesh (ACU5001) have also been added for the HyperWorks CFD interface.
Validation Additions
A new validation case of the Sajben diffuser has been added for compressible flow.
Documentation Additions
In the Command Reference Manual documentation of two forms of definition under Specific Heat have been added, namely, piecewise_bilinear_enthalpy and piecewise_polynomial_enthalpy. The Sutherland viscosity and conductivity models and Carreau-Yasuda viscosity model have been added as well. In the Program Reference Manual documentation has been added for the Altair Compute Console, Element Statistics Output, AcuGetCpCf, AcuInterp and AcuPlotData.

Known Issues

The following known issues will be addressed in a future release as we continuously improve performance of the software:
  • Legacy support for AcuConsole GUI is not supported on Linux versions of RHEL/CentOS higher than 7.5 and SLES versions higher than 15.
  • On Windows platforms, inputs to AcuInterp and AcuPlotData should be given in double quotes, not single quotes.
  • On Windows platforms, solid lines do not display correctly when plotted to .png format from AcuPlotData. Note that when writing to .pdf format solid lines display correctly.

Resolved Issues

  • A conflict with AcuTrace particles and auto_wall surfaces has been resolved.
  • Memory management on AMD platforms has been improved.
  • The incident_radiation variable reference was missing in the AcuTrans documentation.
  • Various typos were corrected in the ACU-T3110 and ACU-T3311 tutorials.
  • In the Programs Reference Manual odgen was corrected to ogden.