By employing Fluent as described in section Two-way coupling algorithm to simulate the transient state of the CFD domain as it is affected by the solid phase, the two-way coupling overcomes the limitations of the one-way coupling mentioned in section 1-way coupling limitations at the expense of being more computationally demanding.
The following limitations apply to the current version of the two-way DEM-CFD coupling module between Ansys Fluent and Rocky:
Note: Unless otherwise specified, these limitations apply to both multiphase and single phase coupling approaches.
Only 3D, unsteady and double precision Fluent cases are supported.
Fixed-time steps must be used (no time step adaptation).
Meshes with polyhedral cells around shadow boundaries are not supported.
Fluent is not allowed to use GPUs.
Eulerian Wall Film model is not supported.
Dense Discrete Phase Model (DDPM) is not supported.
Boiling model is not supported.
Evaporation/Condensation model is not supported.
Multi-Fluid VOF model is not supported.
(Single phase only) Porous zones as participating domains are not supported.
(Multiphase only) Both the Volume Fraction and Backflow Volume Fraction of the dispersed phase handling the particulate phase must be set to 0 at all boundaries.
(Multiphase only) Pressure-Velocity Coupling Scheme must be set to Phase Coupled SIMPLE.
Fixed values in variables for cell zones are not supported.
All Rocky particle sets are be combined to form a single equivalent Eulerian phase in Fluent.
Turbulence dispersion model is only valid for k-epsilon, k-omega and RSM viscous models.
Remeshing is not compatible with sub-stepping method.
Fluent beta features are not allowed.