# What's New

View new features for AcuSolve 2022.3.

## Altair AcuSolve 2022.3 Release Notes

### Highlights

- Equivalent Circuit Modeling
- AcuSolve Topology Optimization Smoothing

### New Features

- Equivalent Circuit Modeling
- AcuSolve’s support of battery modeling takes a huge leap forward allowing you to model charge conservation coupled with the energy equation in two different ways for cylindrical-, prismatic-, and pouch-type cells. The battery Joule heating and multi-scale multi-dimensional (MSMD) approaches fundamentally use equivalent circuit modeling (ECM) to characterize the behavior of the electric circuit even in complex electrical systems. Both approaches support first order ECM modeling for maximum simulation speed and efficiency and second order ECM modeling to capture dynamics of the electrical system behavior more accurately. In the battery Joule heating approach, the thermal impact of the electrical system is accounted for in the energy equation and boundary conditions based on current and voltage where the ECM calculates the current and voltage drop through the homogenous cell. With the MSMD approach, a multi-scale modeling of cell and electrochemical scales is used. Thermal effects of the electrical system result from both Joule heating and from the contribution of electrochemical reactions from the ECM sub-model. With either approach you can model charging, discharging, and drive cycle scenarios. The initial states of charge can be set globally or vary locally. Module inputs of power, voltage, current and c-rate may be specified. Electrical inputs can be constant or a function of time or state of charge. Additionally, two standard charging profiles are available; Constant Current/Constant Voltage (CC-CV) where the charging occurs under a specified current load and switches to a constant voltage once full charge has been achieved and Constant Power/Constant Voltage (CP-CV) where the charging occurs under a specified power load and switches to a constant voltage once full charge has been achieved.

### Enhancements

- AcuSolve Topology Optimization Smoothing
- Topology optimization produces smoother shapes than ever before. You may specify a length scale for the smoothing process.
- Inflow on Arbitrarily Surface
- Mass flow inlet conditions are no longer limited to planar surfaces. Cylindrically curved or arbitrarily shaped surfaces can now be used to define inlet mass flow conditions. The flow direction is relative to the local surface normal allowing for inlets on circumferential surfaces.
- Level Set Explicit Re-distancing
- A more direct approach to calculating the fluid interface in immiscible multiphase simulations is now available with the explicit type of levelset re-distancing. Improvements in speed of up to 20% or more are possible on medium complexity models.
- Model Dimensions to Log File
- In addition to the minimum and maximum extents of the model simulated, the Log file now includes the overall dimensions of the resulting bounding box for easy assessment and confirmation of model size.
- Multiplier Function for Distributed Heat Source
- Multiplier functions were previously only available for fixed heat loads, modifying a single value per element set. In this version, the multiplier function is extended to distributed heat sources, allowing you to define spatially varying heat loads that are also optionally time or time step dependent.
- New SimLab-based Tutorial
- One (1) new tutorial is available in the SimLab CFD user interface. The
new tutorial is:
- ACU-T: 3510/SL 2171: Battery Equivalent Circuit Model

- Updated SimLab-based Tutorials
- Two (2) tutorials have been updated for the SimLab CFD user interface.
The tutorials are:
- ACU-T: 3500/SL 2170: Electric Potential – Automotive Fuse
- ACU-T: 7201/SL 2501: Topology Optimization with Flow Distribution

- New SimLab-based Validation Case
- One (1) new validation case is available in the SimLab CFD user
interface. The new validation case is:
- Viscous Heating Inside a Rotating Annulus

### Resolved Issues

- Error strings written to the Log file due to issues with licensing have been enhanced.
- An issue with conjugate heat transfer and Joule heating has been corrected.
- An error related to mass flux inlets with AcuSolve/EDEM bi-directionally coupled simulations has been corrected.
- A condition preventing torque models to be used with AcuSolve/EDEM bi-directional coupling has been addressed and corrected.
- The setup for leveraging EFA on AWS has been corrected.
- The tutorial input file download links for ACU-T:2100 has been fixed.
- The tutorial input file download links for ACU-T:6104, ACU-T:6105, and ACU-T:6106 have been updated.
- Droplet size notation in ACU-T: 4003 tutorial has been corrected.
- Plots and instructions in the Asymmetric Diffuser and Backward-Facing Step validation cases have been corrected.
- Corrections were made to the viscosity model section of the Command Reference Manual regarding the ramping of viscosity with a multiplier function. Typos in the Command Reference Manual for the udfGetMmoRgdData() user function and convergence check parameters were corrected.
- A brace was removed in the multiplier function example for the multiplier function command.
- A colon was replaced by a semicolon in the user-defined function example for the mesh motion command.
- Corrections were made to the surface tension model of the field interaction model in the Command Reference Manual.

## Altair AcuSolve 2022.2 Release Notes

### Highlights

- AcuSolve/EDEM 3-phase
- AcuTrace ribbon in HyperWorks CFD

### New Features

- AcuSolve/EDEM 3-Phase
- Three phases may now be simulated when coupling AcuSolve with EDEM. Particles are modeled in one phase, a liquid could be modeled in the second phase, and a gas can be modeled as the third phase, for example. As many manufacturing or process-related design simulations require including both a liquid and air along with particles, this new capability widens the range of application for this unique coupling. Surface tension input should be defined and the behavior due to the contact angle definition will be respected for all three phases.

### Enhancements

- AcuTrace
- The particle tracking tool, AcuTrace, previously only available from the AcuConsole interface, has been introduced as a ribbon in the HyperWorks CFD interface. This implementation supports sequential simulations of massless particles or particles with mass, static and dynamic flow fields, and mesh motion. The static mixer tutorial has been updated for the HyperWorks CFD workflow as well.
- Topology Optimization Updates
- Additional constraints can be set on outlet boundaries during a topology optimization simulation allowing you to specify the desired mass flow out of each. Flow can be balanced across all outlets or based on your needs. A strength parameter is now available which impacts how the optimizer determines the minimum volume needed to deliver the fluid.
- Binary Results File Conversion Utility
- You are now able to convert your existing AcuFieldView binary format (.fv) results files to HyperWorks binary (.h3d) results file format with the acuFv2H3D script. The H3D format is readable by all Altair post-processing tools.
- Log File Updates
- You may not be aware that surfaces selected for symmetry conditions are non-planar. A message is now written to the Log file suggesting that you inspect the geometry if the surface is expected to be planar or to consider setting a slip condition instead.
- New HyperWorks CFD-based Tutorials
- Three (3) new tutorials are available in the HyperWorks CFD user
interface. The new tutorials are:
- ACU-T: 2100: Turbulent Flow Over an Airfoil Using the SST Turbulence Model
- ACU-T: 5100: Modeling of a Fan Component Using the Fan Component – Coefficient Method
- ACU-T: 6000: Static Mixer Simulation – AcuTrace

- Updated HyperWorks CFD-based Tutorials
- Three (3) tutorials have been updated for the HyperWorks CFD user
interface. The tutorials are:
- ACU-T: 3600: Melting of Diesel Exhaust Additive within an Enclosed Tank
- ACU-T: 6106: AcuSolve - EDEM Bidirectional Coupling with Mass Transfer
- ACU-T: 6500: Flow Through Porous Medium

- New SimLab-based Tutorials
- Two (2) new tutorials are available in the SimLab user interface. The
new tutorials are:
- ACU-T: 6107 / SL 2450: AcuSolve EDEM Bidirectional 3-Phase Coupling
- ACU-T: 7201 / SL 2501: Topology Optimization with Flow Distribution

- Updated SimLab-based Tutorials
- Five (5) tutorials have been updated for the SimLab user interface. The
tutorials are:
- ACU-T: 3500 / SL 2170: Electric Potential – Automotive Fuse
- ACU-T: 6101 / SL 2431: Particle Separation in a Windshifter using AcuSolve-EDEM Unidirectional Coupling
- ACU-T: 6102 / SL 2432: Particle Separation in a Windshifter using AcuSolve-EDEM Bidirectional Coupling
- ACU-T: 6103 / SL 2433: AcuSolve – EDEM Bidirectional Coupling with Heat Transfer
- ACU-T: 6104 / SL 2440: AcuSolve – EDEM Bidirectional Coupling with Non-Spherical Particles

- New HyperWorks CFD-based Validation Cases
- One (1) new validation case is available in the SimLab user interface.
The new validation case is:
- Ideal Gas Compression in an Actuating Piston

- New SimLab-based Validation Cases
- Four (4) new validation cases are available in the SimLab user
interface. The new validation cases are:
- Turbulent Flow Through a Heated Periodic Channel
- Turbulent Flow Past a Wall-Mounted Hump
- Turbulent Flow Over an Oscillating Rigid Body Assembly
- Laminar Couette Flow with Imposed Pressure Gradient and Heated Walls

### Resolved Issues

- An issue with IMPI runs not using InfiniBand interconnect has been corrected.
- Improvements to SSI search on large number of procs.
- A correction has been made to properly include the rotational motion of a fluid region when calculating a time-averaged flow field for the time_average_velocity_regular variable.
- AcuRun on Linux now handles parentheses in directory names.
- An issue where unphysical temperatures were observed in AcuSolve/EDEM bi-directionally coupled runs with mass transfer has been corrected.
- Multiple volume sets are now accepted in the specification of the design space volume for topology optimization.
- Corrections have been made to the electric potential tutorial in SimLab, ACU-T: 3500 / SL 2170.

## Altair AcuSolve 2022.1 Release Notes

### Highlights

- 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.

### Enhancements

- 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:
- New SimLab-based Tutorials
- Five (5) new SimLab-based tutorials are available on the SimLab Learning Center (web.altair.com/altair-for-simlab-learning-center-trls). The new tutorials are:
- New SimLab-based Validation Cases
- Five (5) new validation cases are available in the SimLab user interface. The new validation cases are:
- 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.

### 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.

## Altair AcuSolve 2022 Release Notes

### Highlights

- Euler-Euler Multiphase
- Granular Multiphase
- Electric Potential Solver

### New Features

- Euler-Euler Multiphase
- AcuSolve’s multiphase capabilities expand yet again in version 2022 with the introduction of Eulerian-Eulerian multiphase. With this feature you can include the exchange of momentum between multiphase fields. As with the Algebraic Eulerian mixture multiphase model the dispersed fields can be of any material type, liquid, solid, or gas. In addition, inflow conditions of each phase may be defined separately via any of the following phasic inflow types: cartesian, cylindrical, or spherical velocity, normal velocity, mass flux, or volumetric flow rate.
- Granular Flow Multiphase
- With the addition of Eulerian-Eulerian multiphase you also have the option to include solid pressure and solid viscosity effects when modeling dispersed solid phases. When simulating granular flows, the granular temperature, a representation of the random oscillations of particles, the particle restitution, which defines the fraction of a particle’s momentum after collision, and the angle of internal friction, a measure of the ability of a unit of rock or soil to withstand a shear stress, may all be specified by you.
- Electric Potential Solver
- Solve for the thermal effects of a voltage drop or prescribed current or current density by activating Joule heating under the electric potential solver in AcuSolve 2022. This electrostatic solution to charge conservation allows you to vary the available electric boundary conditions through multiplier function control so that accurate duty cycles can be simulated.
- AcuSolve Help delivered in separate package
- A new package, hwCFDSolversHelp, including reference manual, training manual, and validation manual documentation is now available for download and install from Altair One. This package can be installed whether hwCFDSolvers is installed or not. Model files for tutorials and validations are available online from a link in the Help documentation as well as from Altair One.

### Enhancements

- AcuSolve/EDEM Drag and Lift model user-defined functions
- Custom definitions of drag and lift models for use with AcuSolve/EDEM coupling simulations can now be specified via the user_function value for drag_model and lift_model under the FIELD_INTERACTION_MODEL definition. You are encouraged to test their functions for range and validity prior to simulation as no bound or specific error checking is performed in AcuSolve/EDEM coupled simulations. See the AcuSolve User-Defined Functions Manual for information about creating and referencing user-defined functions.
- Improvements to Topology Optimization
- Improvements have been made to AcuSolve’s integrated topology optimization that increase the speed of convergence and improve the overall robustness. Porous zones are now supported, lower viscosity fluids are now handled more precisely, and you are notified when unsupported physics are selected, or no design space volume is found.
- Ogden ALE Mesh Motion
- You can now easily switch between different Arbitrary Lagrangian-Eulerian (ALE) mesh motion techniques directly in the input deck. A new ALE mesh equation option, previously available through the aletech cnf parameter, named ale_ogden, activates Ogden mesh motion. Mesh motion based on mesh quality metrics is activated by using the previously available ale mesh equation.
- New HyperWorks CFD-based Tutorials
- Two (2) new tutorials are available in the HyperWorks CFD user
interface. The new tutorials are:
- ACU-T: 4101: Eulerian-Eulerian Multiphase
- ACU-T: 4102: Granular Flow

- New SimLab-based Tutorials
- Sixteen (16) new tutorials are available in the SimLab user interface.
The new tutorials are:
- ACU-T: 2300 / SL 2060: Atmospheric Boundary Layer Problem – Flow Over Building
- ACU-T: 2400 / SL 2030: Supersonic Flow in a Converging-Diverging Nozzle
- ACU-T: 3310 / SL 2160: Single Phase Nucleate Boiling
- ACU-T: 3311 / SL 2161: Multiphase Nucleate Boiling using the Algebraic Eulerian Model
- ACU-T: 3500 / SL 2170: Electric Potential
- ACU-T: 4002 / SL 2220: Sloshing of Water in a Tank
- ACU-T: 4003 / SL 2260: Freely Falling Water Droplet
- ACU-T: 4101 / SL 2231: T-junction Flow using the Eulerian Multiphase Model
- ACU-T: 4102 / SL 2232: Fluidized Bed using Granular Multiphase Model
- ACU-T: 5403 / SL 2421: Piezoelectric Flow Energy Harvester: A Fluid-Structure Interaction
- ACU-T: 6100 / SL 2430: Particle Separation in a Windshifter using Altair EDEM
- ACU-T: 6101 / SL 2431: Particle Separation in a Windshifter using AcuSolve – EDEM Unidirectional Coupling
- ACU-T: 6102 / SL 2432: Particle Separation in a Windshifter using AcuSolve – EDEM Bidirectional Coupling
- ACU-T: 6103 / SL 2433: AcuSolve – EDEM Bidirectional Coupling with Heat Transfer
- ACU-T: 6104 / SL 2440: AcuSolve – EDEM Bidirectional Coupling with Non-Spherical Particles
- ACU-T: 7200 / SL 2500: Topology Optimization

- New SimLab-based Validation Cases
- Four (4) new validation cases are available in the SimLab user
interface. The new validation cases are:
- Turbulent Flow Through a Pipe
- Laminar Flow Through a Channel with Heated Walls
- Laminar Couette Flow with Imposed Pressure Gradient
- Laminar Flow Past a 90° T-Junction

- MicroSoft Visual Studio 2019 Support
- Support for MicroSoft Visual Studio 2019, Community, Professional, and Enterprise versions, has been added. The compiler version and location in use are also reported to you.
- Reference Frame on Interface Surfaces [Beta]
- A beta release of hybrid use of reference frame and sliding mesh is available by activating the hybridmrf configuration parameter. This feature allows you to take larger time steps when simulating sliding meshes.

### Resolved Issues

- AcuConsole and AcuFieldView have been officially retired and are no longer shipped with AcuSolve (hwCFDSolvers).
- References to AcuConsole and AcuFieldView have been removed from documentation.
- The -tlog, -lprobe, -acutail, and -acuprobe options have been removed from the AcuRun command.
- The default lift model for the Eulerian-Eulerian and Algebraic Eulerian multiphase types has been set to none.
- An issue with interior thermal shells allowing thermal conduction at shell ends has been fixed.
- EDEM particle volume fractions are now correctly handled during mesh contraction and expansion.
- AcuSolve GPU acceleration has been updated to CUDA 10.2.
- An error with PQ curve input to the FAN_COMPONENT has been corrected.
- An issue when specifying pressure inlets with the humid air model has been fixed.
- An error with initializing the eddy viscosity field when initialize_Stokes = on has been fixed.
- An issue with specifying nodal initial conditions by element set has been corrected.
- Changes were made that improve the steady state solution using the ideal gas density model.
- In the Command Reference Manual, non-spherical lift and torque model information was added under FIELD_INTERACTION_MODEL.
- In the Programs Reference Manual, information about setting the number of threads for AcuPrep under the AcuRun command has been added.
- HyperMesh-based tutorials have been updated to reference HyperGraph for 2D plotting.