Homeenable_cfd_coupling command
Purpose
Command for coupling with a CFD simulation, e.g. CFDEMcoupling.
Warning
GPU support for this command has not been tested and may not work as expected.Syntax
enable_cfd_coupling keyword value
With the following keyword argument pairs:
Keywords |
Description |
|---|---|
verbose |
value setting the verbosity level. One of the following options:
default:
0 |
port_file_path |
The path where to store portOffset files.
This setting must coincide with the setting for the
twoWaySocket model on CFD side.
(default: “../DEM/”)
|
port_base |
the base port to start searching for available ports
(default:
49152) |
timeout |
wait time in seconds for start up of DEM solver and successful
socket connection
(default: 10)
|
keep_port_file |
sets if port files are kept when closing the socket.
valid values:
yes or no(default:
no, i.e. delete portFiles) |
treat_multispheres_as_spheres |
treat multisphere particles as individual spheres on CFD side.
(
yes or no)(default:
no) |
add_fluid_mass |
account for additional fluid mass during integration,
yes or no
Additional required keyword value pairs:
If using this setting, the particle mass is increased by
 .(default:
no) |
activate heat transfer between particles and fluid,
yes or no(default:
no) |
|
activate transfer of chemical species between particles and fluid,
yes or no(default:
no) |
|
liquid_transport |
activate transfer of liquid between particles and fluid,
yes or no(default:
no) |
track_spray_collisions |
activate tracking of spray-particle collisions, if
liquid_transport yes.
Also activates liquid_transport if not set by user.(default:
no) |
attrition_transport |
activate transfer of attrition between particles and fluid,
yes or no(default:
no) |
activate surface film on particles and interaction with fluid,
yes or no(default:
no) |
|
list of properties that are changed due to reactions, available properties are
mass and size(default:
{} , requires surface_film yes) |
|
photon_reflection |
(default:
no) |
Examples
enable_cfd_coupling
enable_cfd_coupling verbose 1
enable_cfd_coupling heat_transfer yes
enable_cfd_coupling species_convection yes species_name H2O species_initial_value 0.01
enable_cfd_coupling attrition_transport yes
enable_cfd_coupling liquid_transport yes track_spray_collisions yes
enable_cfd_coupling surface_film yes
enable_cfd_coupling surface_film yes variable_properties {mass,size}
Description
Adds interaction with a CFD simulation running in parallel. Calculation of drag forces is done on the CFD side and received by Aspherix.
Note
This command will attempt to open a socket connection to a running CFD simulation which must open a corresponding socket for communication. This command will try to configure the exchanged data automatically.
Setting species_convection yes will set up an internal scalar transport equation
to model particle-particle exchange of the species upon particle contacts.
The following additional keyword value pairs are read in this case:
Keywords |
Description |
|---|---|
species_name |
the species name
mandatory
|
species_initial_value |
the initial value of the species on particles
mandatory
|
Setting track_spray_collisions yes will also active liquid_transport. This is
a simplification for user convenience.
Setting heat_transfer yes will enable considering fluid-particle heat transfer.
Heat transfer is treated in the manner specified by the settings of the corresponding
LaEuScalarTemp forceModel on the CFD side.
This model must be used. For postprocessing fluid-particle heat transfer the following
properties are available:
heatFlux = conductive heatflux + (explicit/implicit) convective heatflux
convectiveHeatFlux = (explicit/implicit) convective heatflux
Therefore, independent settings, the convective heatflux, the (convective + conductive) heatflux and by subtraction the conductive heatflux can be obtained.
Surface film
Setting surface_film yes will set up models for coupling fluid-particle mass
transfer due to chemical reactions. The masstransfer of all solidSpecies
defined on the CFd side in chemistryProperties/VoidChemistryModelProps is
commuicated to the DEM. It is necessary to provide information about the composition
of each particle. This is done by defining
composition_properties and providing the composition
information to the particle_template.
By defining the variable_properties list, the user can select whether mass
and/or size of the particle should change due to masstransfer with CFD.
Note
This command should be the last command in the Aspherix input script before the output is configured. Especially it should not precede enable_gravity, enable_heat_transfer, simulation_timestep or particle_template commands if these are present in the simulation / script. Moreover, this command resets the write interval defined by write_output_timestep if an output_settings command was defined before.
Restrictions
Requires a CFDEMcoupling simulation running alongside using the twoWaySocket model (or an equivalent setup).
surface_species_names is a deprecated input for defining a list of the species names constituting the surface film. Please use the new composition_properties framework. surface_species_initial_values is a deprecated input for defining list of initial values (optional, if not given all species are initialized as 0). Please use the new composition_properties framework.
It is not allowed to use the enable_buoyancy command together with the
enable_cfd_coupling command.