DETCHEM Plug Driver

This document describes the configuration directives that are available for use with the DETCHEM Batch driver.

The plug code simulates the behavior of plug flow chemical reactors. The code is designed for the non-dispersive one dimensional flow of chemically reacting ideal gas mixture.

SI units are used exclusively throughout the program. Be sure to convert all values before importing data into CaRMeN. When referring to chemical species, use the correct capitalization, i.e. Ar instead of AR. Not doing so will lead to simulation errors since the species names will not be recognized.

Driver Name

This driver is available under the name detchem_plug.

Output Resources

This driver outputs a single tabular data resource. The primary key is the axial position z of the reactor.

• mole_fractions - The species mole fractions as function of reactor position.

Parameters

The following parameters are available.

# The pressure in the reactor (in this example: 0.5bar)
pressure: 0.5e5       # Pa      

# An object that defines the conditions of the gas flow entering the reactor,
# i.e. initial conditions
inlet:
  temperature: 429    # K
  gas_velocity: 0.47  # m/s
  # The composition of the gas entering the channel
  mole_fractions:
    CH4: 0.173
    O2: 0.19
    # An asterisk can be used to denote the remainder to unity.  It must be enclosed in quotes!
    N2: "*"           

# A list of "section objects". Each section describes the geometrical parameters of the cylinder
# along with a wall temperature.
# The typical case is a list with only one entry as shown here.
sections:
  -
    length: 0.3         # m
    radius: 0.02        # m
    wall_temperature: 500 # K

# The ratio of catalytically active surface area and geometrical surface area.
f_cat_geo: 94.5       # dimensionless

# A complex object type describing the chemical model.
# Use the chemical-model loader to produce a resource with the correct structure,
# then access is using the $resource macro as shown here.
chemical_model:
  $resource: ./chemical_model


#
# Optional parameters follow below.
# The given values are the default values used when the parameter is omitted.
#

# An object describing the properties of the washcoat. Currently, only the effectiveness model
# is supported. Please file a feature request at https://gitlab.com/carmenjs/carmen/issues
# if you also need detailed washcoat models. The default is not to consider a washcoat model.
# Although the washcoat key itself is optional, the properties within the washcoat are not.
washcoat:
  thickness: 4e-5     # m  
  pore_diameter: 1e-8 # m
  tortuosity: 3       # dimensionless
  porosity: 0.6       # dimensionless
  # A list of diffusion limiting species used in the effectiveness factor model.
  diffusion_limiting_species:
    - CH4

# Settings pertaining to the numerical solution.
solver:
  absolute_tolerance: 1e-16
  relative_tolerance: 1e-6
  initial_integration_step_size: 1e-10
  max_integration_step_size: 1

# Settings for the solution of chemical source terms of surface reactions
chem_surf:
  initial_integration_step_size: 1e-10
  integration_time: 10.0
  max_integration_step_size: 1.0
  absolute_tolerance: 1e-20
  relative_tolerance: 1e-6