Initial conditions ================== The following inputs are defined using the prefix ``ic``: +-----------------------+------------------------------------------------------------------------+-------------+-----------+ | | Description | Type | Default | +=======================+========================================================================+=============+===========+ | regions | Regions used to define initial conditions. Supported region shapes | Strings | None | | | include a ``box``, ``cylinder``, and ``sphere``. | | | +-----------------------+------------------------------------------------------------------------+-------------+-----------+ | allow_regions_overlap | If enabled, particles will be generated/initialized more than once | Int | 1 | | | on areas where the IC regions intersect. This only applied to particle | | | | | initializations. Fluid initial conditions are applied in the order | | | | | defined in the inputs file, with later regions overwriting earlier | | | | | ones. | | | +-----------------------+------------------------------------------------------------------------+-------------+-----------+ Fluid settings ~~~~~~~~~~~~~~ For each initial condition region, the fluid inputs are defined using the compound prefix ``ic.[region_name].[fluid_name]``: +------------------------+------------------------------------------------------------------------+-------------+-----------+ | | Description | Type | Default | +========================+========================================================================+=============+===========+ | volfrac | Volume fraction [required] | Real | 0 | +------------------------+------------------------------------------------------------------------+-------------+-----------+ | density | Fluid density | Real | 0 | +------------------------+------------------------------------------------------------------------+-------------+-----------+ | velocity | Velocity components | Reals<3> | 0 0 0 | +------------------------+------------------------------------------------------------------------+-------------+-----------+ | pressure | Fluid pressure | Real | 0 | +------------------------+------------------------------------------------------------------------+-------------+-----------+ | temperature | Fluid temperature | Real | 0 | +------------------------+------------------------------------------------------------------------+-------------+-----------+ | species.[species_name] | Mass fraction of ``species_name``. Species must be a fluid species. | Real | 0 | +------------------------+------------------------------------------------------------------------+-------------+-----------+ .. _InputsICSolids: Solids settings ~~~~~~~~~~~~~~~ For each initial condition region, general solids inputs are defined using the compound prefix ``ic.[region_name]``: +----------------------+------------------------------------------------------------------+-------------+-----------+ | | Description | Type | Default | +======================+==================================================================+=============+===========+ | solids | Name of solid type in IC region. Only one solid is allowed in | String | None | | | an IC region. | | | +----------------------+------------------------------------------------------------------+-------------+-----------+ | packing | Specifies how auto-generated particles are placed in the IC | String | None | | | region: | | | | | | | | | | Options: | | | | | | | | | | * ``hcp`` - hex-centered packing | | | | | * ``pseudo_random`` -- random packing using a fixed random seed | | | | | * ``random`` -- random packing (not repeatable) | | | | | * ``oneper`` -- one particle per cell | | | | | * ``eightper`` -- eight particles per cell | | | | | * ``n-cube`` -- n^3 particles per cell where n is an integer | | | | | | | | | | (NOTE: ``oneper`` is equivalent to ``1-cube`` and ``eightper`` | | | | | to ``2-cube``) | | | +----------------------+------------------------------------------------------------------+-------------+-----------+ For each initial condition region, the solid inputs are defined using the compound prefix ``ic.[region_name].[solid_name]``: +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | | Description | Type | Default | +========================+=======================================================================+=============+===========+ | volfrac | Volume fraction | Real | 0 | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | temperature | Temperature | Real | 0 | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | species.[species_name] | Mass fraction of `species_name`. Must be a solid species. | Real | 0 | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | velocity | Velocity components | Reals<3> | 0 0 0 | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ For automatically generated particles, diameter and density distributions can be specified. The following inputs control the diameter distribution and are defined with the prefix ``ic.[region_name].[solid_name].diameter``: Note that diameter distributions must define a weighting type, please refer to :ref:`ReferenceParticleDistributions `. +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | | Description | Type | Default | +========================+=======================================================================+=============+===========+ | distribution | Type of distribution for particle diameter in the IC region. This is | String | None | | | only used for auto-generated particles. | | | | | | | | | | Options: | | | | | | | | | | * ``constant`` - specified constant | | | | | * ``uniform`` - uniform distribution | | | | | * ``normal`` - normal distribution | | | | | * ``log-normal`` - log-noremal distribution | | | | | * ``custom`` - user-defined distribution | | | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | weighting | Weighting for diameter distribution. | String | N/A | | | | | | | | Options: | | | | | | | | | | * ``number-weighted`` | | | | | * ``volume-weighted`` | | | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | bins | Number of bins used when discretizing the diameter distribution to | Int | 64 | | | approximate the number of particles within an initial condition | | | | | region. | | | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | constant | Monodisperse (single valued) particle diameter. | Real | 0 | | | Required for ``constant`` distributions. | | | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | mean | Distribution mean. | Real | 0 | | | Required for ``normal`` and ``log-normal`` distributions. | | | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | std | Distribution standard deviation. | Real | 0 | | | Required for ``normal`` and ``log-normal`` distributions. | | | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | min | Minimum diameter to clip distribution. | Real | 0 | | | Required for ``normal``, ``log-normal``, and ``uniform`` | | | | | distributions. | | | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | max | Maximum diameter to clip distribution. | Real | 0 | | | Required for ``normal``, ``log-normal``, and ``uniform`` | | | | | distributions. | | | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | custom | File name that specifies either the cumulative or probability | String | None | | | distribution. Required for ``custom`` distributions. | | | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ The following inputs control the density distribution and are defined with the prefix ``ic.[region_name].[solid_name].density``: +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | | Description | Type | Default | +========================+=======================================================================+=============+===========+ | distribution | Type of distribution for particle density in the IC region. This is | String | None | | | only used for auto-generated particles. | | | | | | | | | | Options: | | | | | | | | | | * ``constant`` - specified constant | | | | | * ``uniform`` - uniform distribution | | | | | * ``normal`` - normal distribution | | | | | * ``log-normal`` - log-noremal distribution | | | | | * ``custom`` - user-defined distribution | | | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | constant | Monodisperse (single valued) particle diameter. | Real | 0 | | | Required for ``constant`` distributions. | | | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | mean | Distribution mean. | Real | 0 | | | Required for ``normal`` and ``log-normal`` distributions. | | | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | std | Distribution standard deviation. | Real | 0 | | | Required for ``normal`` and ``log-normal`` distributions. | | | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | min | Minimum density to clip distribution. | Real | 0 | | | Required for ``normal``, ``log-normal``, and ``uniform`` | | | | | distributions. | | | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | max | Maximum density to clip distribution. | Real | 0 | | | Required for ``normal``, ``log-normal``, and ``uniform`` | | | | | distributions. | | | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ | custom | File name that specifies either the cumulative or probability | String | None | | | distribution. Required for ``custom`` distributions. | | | +------------------------+-----------------------------------------------------------------------+-------------+-----------+ The following inputs must be preceded by the prefix ``mfix``: +----------------------+-----------------------------------------------------------------------+-------------+--------------+ | | Description | Type | Default | +======================+=======================================================================+=============+==============+ | particle_init_type | Particle initialization method. | String | ASCIIFile | | | | | | | | Options: | | | | | | | | | | * ``Auto`` - automatic particle generation | | | | | * ``ASCIIFile`` - read particle data from file ``particle_input.dat`` | | | | | | | | +----------------------+-----------------------------------------------------------------------+-------------+--------------+ The following input must be preceded by the prefix ``particles``: +--------------------+---------------------------------------------------------------------------+-------------+-----------+ | | Description | Type | Default | +====================+===========================================================================+=============+===========+ | removeOutOfRange | Remove particles at initialization that are touching a wall. | Int | 1 | +--------------------+---------------------------------------------------------------------------+-------------+-----------+ Below is an example for specifying an initial condition for a fluid (``fluid``) and one solid (``solid0``). .. code-block:: none mfix.particle_init_type = Auto particles.removeOutOfRange = 1 ic.regions = bed0 bed1 ic.bed0.fluid.volfrac = 0.725 ic.bed0.fluid.density = 1.0 ic.bed0.fluid.velocity = 0.015 0.00 0.00 ic.bed0.fluid.temperature = 383.0 ic.bed0.fluid.species.CO = 0.3 ic.bed0.fluid.species.CO2 = 0.2 ic.bed0.fluid.species.O2 = 0.5 ic.bed0.solids = my_solid0 ic.bed0.packing = pseudo_random ic.bed0.my_solid0.volfrac = 0.275 ic.bed0.my_solid0.temperature = 400.0 ic.bed0.my_solid0.species.Fe2O3 = 0.4 ic.bed0.my_solid0.species.FeO = 0.6 ic.bed0.my_solid0.velocity = 0.00 0.00 0.00 ic.bed0.my_solid0.diameter.distribution = constant ic.bed0.my_solid0.diameter.constant = 100.0e-6 ic.bed0.my_solid0.density.distribution = constant ic.bed0.my_solid0.density.constant = 1000.0 ic.bed1.fluid.volfrac = 0.925 ic.bed1.fluid.density = 1.0 ic.bed1.fluid.velocity = 0.015 0.00 0.00 ic.bed1.fluid.temperature = 383.0 ic.bed1.fluid.species.CO = 0.5 ic.bed1.fluid.species.CO2 = 0.5 ic.bed1.fluid.species.O2 = 0.0 ic.bed1.solids = solid0 ic.bed1.packing = pseudo_random ic.bed1.solid0.volfrac = 0.075 ic.bed1.solid0.temperature = 450.0 ic.bed1.solid0.species.Fe2O3 = 0.0 ic.bed1.solid0.species.FeO = 1.0 ic.bed1.solid0.velocity = 0.10 0.00 0.00 ic.bed1.solid0.diameter.distribution = uniform ic.bed1.solid0.diameter.weighting = number-weighted ic.bed1.solid0.diameter.bins = 20 ic.bed1.solid0.diameter.min = 90.0e-6 ic.bed1.solid0.diameter.max = 110.0e-6 ic.bed1.solid0.density.distribution = normal ic.bed1.solid0.density.mean = 900.0 ic.bed1.solid0.density.std = 30.0 ic.bed1.solid0.density.min = 800.0 ic.bed1.solid0.density.max = 1000.0