What's New in Altair AcuSolve 2022
Eulerian-Eulerian Multiphase
Eulerian-Eulerian multiphase is the most comprehensive multiphase model, conserving momentum and continuity of the carrier fluid as well as each of the active disperse phases. Altair AcuSolve v2022.0 is proud to offer this new feature as we continue to expand the depth and breadth of our multiphase capability. Whether simulating water droplets in air, bubbles in oil, or dust through a vacuum hose, the interaction between the disperse phase and the carrier fluid will be accurately captured.
2D Bubble Separator
The disperse field is modeled as an ensemble-averaged cloud so individual particles are not tracked specifically but the carrier field has no constraint on density, especially as it relates to the dispersed fields. Since the momentum field, and therefore velocity, is calculated for each phase in the simulation users can optionally specify a velocity at inlets for individual phases, known as phasic velocity, in addition to the distribution of volume fractions. This also allows for output of the velocity field for specific phases.
Users should consider the Eulerian-Eulerian model in place of the Algebraic Eulerian model when the carrier field is lighter than the dispersed fields, when phasic velocities should be specified, or when accuracy of the solution significantly outweighs the need for a quick turnaround of the simulation.
This latest addition to AcuSolve’s multiphase toolset provides users with more options for simulating multiple-fluid scenarios while providing a foundation for further multiphase features.
Granular Multiphase
The addition of Eulerian-Eulerian multiphase opens the door to many new types of multiphase features. The first of which is Granular multiphase flow. When including disperse solids in your multiphase simulation there will likely be the need to model a collection of particles exhibiting dense phase flow. When the volume fraction of solid particles reaches above 20% additional models and parameters provided by the Granular multiphase feature should be used. With this new feature come new drag models that are appropriate for dense phase flow. New models for particle kinetics, collisions, and friction ensure that even the ensemble-averaged approach to modeling particles in flow captures the correct behavior for particle-particle and particle-wall interactions. This is a multiphase continuum approach to modeling particles so there is no individual particle tracking or definition. As such, particle shapes are assumed to be isometric or nearly approximated as spherical.
Sand collected by a vacuum
Reduction of the size of the sand pile
Performance of vacuum collecting sand
Granular multiphase and AcuSolve/EDEM coupling complement each other well with only minimal overlap regarding choice of approach. First, regarding particle size, if less than 50 microns modeling particles as a continuum is recommended. If greater than 80 microns, then the coupled CFD/DEM approach could be appropriate if particle tracking becomes important. Above 1 mm in size users are recommended to use the coupled CFD/DEM approach. Tracking individual particles above a few million becomes excessive for the coupled approach so if this is needed, the continuum method is recommended. Finally, if the particle motion is highly dependent on its shape and its shape is non-isometric then the coupled method must be used.
Electric Potential Solver
Electrical inputs inevitably produce thermal effects. When the thermal effects become significant higher accuracy results can be obtained when voltages and currents are specified directly. AcuSolve’s Electric Potential solver allows users to incorporate electrical boundary conditions in their simulations by solving for the conservation of charge. This new feature further expands AcuSolve's capability in the area of electrical simulation. Duty cycles can easily be modeled using multiplier functions on voltage or current boundary conditions.
Steady Load
Transient Load
Heat generation due to electric current and ground voltage