- variableThe name of the variable that this boundary condition applies to
C++ Type:NonlinearVariableName

Description:The name of the variable that this boundary condition applies to

- boundaryThe list of boundary IDs from the mesh where this boundary condition applies
C++ Type:std::vector

Description:The list of boundary IDs from the mesh where this boundary condition applies

# ChemicalOutFlowBC

Chemical flux boundary condition

Integrated boundary condition to specify on the boundary, which arises from integation by parts on the diffusion term (1) where is porosity and is the diffusivity.

## Input Parameters

- displacementsThe displacements
C++ Type:std::vector

Options:

Description:The displacements

### Optional Parameters

- enableTrueSet the enabled status of the MooseObject.
Default:True

C++ Type:bool

Options:

Description:Set the enabled status of the MooseObject.

- save_inThe name of auxiliary variables to save this BC's residual contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)
C++ Type:std::vector

Options:

Description:The name of auxiliary variables to save this BC's residual contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

- use_displaced_meshFalseWhether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.
Default:False

C++ Type:bool

Options:

Description:Whether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

- control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector

Options:

Description:Adds user-defined labels for accessing object parameters via control logic.

- seed0The seed for the master random number generator
Default:0

C++ Type:unsigned int

Options:

Description:The seed for the master random number generator

- diag_save_inThe name of auxiliary variables to save this BC's diagonal jacobian contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)
C++ Type:std::vector

Options:

Description:The name of auxiliary variables to save this BC's diagonal jacobian contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

- implicitTrueDetermines whether this object is calculated using an implicit or explicit form
Default:True

C++ Type:bool

Options:

Description:Determines whether this object is calculated using an implicit or explicit form

### Advanced Parameters

- vector_tagsnontimeThe tag for the vectors this Kernel should fill
Default:nontime

C++ Type:MultiMooseEnum

Options:nontime time

Description:The tag for the vectors this Kernel should fill

- extra_vector_tagsThe extra tags for the vectors this Kernel should fill
C++ Type:std::vector

Options:

Description:The extra tags for the vectors this Kernel should fill

- matrix_tagssystemThe tag for the matrices this Kernel should fill
Default:system

C++ Type:MultiMooseEnum

Options:nontime system

Description:The tag for the matrices this Kernel should fill

- extra_matrix_tagsThe extra tags for the matrices this Kernel should fill
C++ Type:std::vector

Options:

Description:The extra tags for the matrices this Kernel should fill

### Tagging Parameters

## Input Files

- modules/chemical_reactions/test/tests/parser/equilibrium_without_action.i
- modules/chemical_reactions/examples/calcium_bicarbonate/calcium_bicarbonate.i
- modules/chemical_reactions/test/tests/aqueous_equilibrium/1species_without_action.i
- modules/chemical_reactions/test/tests/aqueous_equilibrium/1species.i
- modules/chemical_reactions/test/tests/parser/equilibrium_action.i
- modules/chemical_reactions/test/tests/aqueous_equilibrium/2species_without_action.i
- modules/chemical_reactions/test/tests/aqueous_equilibrium/2species_with_density.i
- modules/chemical_reactions/test/tests/aqueous_equilibrium/2species_eqaux.i
- modules/chemical_reactions/test/tests/aqueous_equilibrium/2species.i

#### modules/chemical_reactions/test/tests/parser/equilibrium_without_action.i

```
# Test AqueousEquilibriumReactions parser
[Mesh]
type = GeneratedMesh
dim = 2
[]
[Variables]
[./a]
[../]
[./b]
[../]
[]
[AuxVariables]
[./pressure]
[../]
[./pa2]
[../]
[./pab]
[../]
[]
[AuxKernels]
[./pa2]
type = AqueousEquilibriumRxnAux
variable = pa2
v = a
log_k = 2
sto_v = 2
[../]
[./pab]
type = AqueousEquilibriumRxnAux
variable = pab
v = 'a b'
log_k = -2
sto_v = '1 1'
[../]
[]
[ICs]
[./a]
type = BoundingBoxIC
variable = a
x1 = 0.0
y1 = 0.0
x2 = 1.0e-10
y2 = 1
inside = 1.0e-2
outside = 1.0e-10
[../]
[./b]
type = BoundingBoxIC
variable = b
x1 = 0.0
y1 = 0.0
x2 = 1.0e-10
y2 = 1
inside = 1.0e-2
outside = 1.0e-10
[../]
[./pressure]
type = FunctionIC
variable = pressure
function = 2-x
[../]
[]
[Kernels]
[./a_ie]
type = PrimaryTimeDerivative
variable = a
[../]
[./a_diff]
type = PrimaryDiffusion
variable = a
[../]
[./a_conv]
type = PrimaryConvection
variable = a
p = pressure
[../]
[./b_ie]
type = PrimaryTimeDerivative
variable = b
[../]
[./b_diff]
type = PrimaryDiffusion
variable = b
[../]
[./b_conv]
type = PrimaryConvection
variable = b
p = pressure
[../]
[./a1_eq]
type = CoupledBEEquilibriumSub
variable = a
log_k = 2
weight = 2
sto_u = 2
[../]
[./a1_diff]
type = CoupledDiffusionReactionSub
variable = a
log_k = 2
weight = 2
sto_u = 2
[../]
[./a1_conv]
type = CoupledConvectionReactionSub
variable = a
log_k = 2
weight = 2
sto_u = 2
p = pressure
[../]
[./a2_eq]
type = CoupledBEEquilibriumSub
variable = a
v = b
log_k = -2
weight = 1
sto_v = 1
sto_u = 1
[../]
[./a2_diff]
type = CoupledDiffusionReactionSub
variable = a
v = b
log_k = -2
weight = 1
sto_v = 1
sto_u = 1
[../]
[./a2_conv]
type = CoupledConvectionReactionSub
variable = a
v = b
log_k = -2
weight = 1
sto_v = 1
sto_u = 1
p = pressure
[../]
[./b2_eq]
type = CoupledBEEquilibriumSub
variable = b
v = a
log_k = -2
weight = 1
sto_v = 1
sto_u = 1
[../]
[./b2_diff]
type = CoupledDiffusionReactionSub
variable = b
v = a
log_k = -2
weight = 1
sto_v = 1
sto_u = 1
[../]
[./b2_conv]
type = CoupledConvectionReactionSub
variable = b
v = a
log_k = -2
weight = 1
sto_v = 1
sto_u = 1
p = pressure
[../]
[]
[BCs]
[./a_left]
type = DirichletBC
variable = a
boundary = left
value = 1.0e-2
[../]
[./a_right]
type = ChemicalOutFlowBC
variable = a
boundary = right
[../]
[./b_left]
type = DirichletBC
variable = b
boundary = left
value = 1.0e-2
[../]
[./b_right]
type = ChemicalOutFlowBC
variable = b
boundary = right
[../]
[]
[Materials]
[./porous]
type = GenericConstantMaterial
prop_names = 'diffusivity conductivity porosity'
prop_values = '1e-4 1e-4 0.2'
[../]
[]
[Executioner]
type = Transient
solve_type = PJFNK
nl_abs_tol = 1e-12
end_time = 10
dt = 10
[]
[Outputs]
file_base = equilibrium_out
exodus = true
perf_graph = true
print_linear_residuals = true
[]
[Preconditioning]
[./smp]
type = SMP
full = true
[../]
[]
```

#### modules/chemical_reactions/examples/calcium_bicarbonate/calcium_bicarbonate.i

```
# Example of reactive transport model with precipitation and dissolution.
# Calcium (ca2) and bicarbonate (hco3) reaction to form calcite (CaCO3).
# Models bicarbonate injection following calcium injection, so that a
# moving reaction front forms a calcite precipitation zone. As the front moves,
# the upstream side of the front continues to form calcite via precipitation,
# while at the downstream side, dissolution of the solid calcite occurs.
#
# The reaction network considered is as follows:
# Aqueous equilibrium reactions:
# a) h+ + hco3- = CO2(aq), Keq = 10^(6.341)
# b) hco3- = h+ + CO23-, Keq = 10^(-10.325)
# c) ca2+ + hco3- = h+ + CaCO3(aq), Keq = 10^(-7.009)
# d) ca2+ + hco3- = cahco3+, Keq = 10^(-0.653)
# e) ca2+ = h+ + CaOh+, Keq = 10^(-12.85)
# f) - h+ = oh-, Keq = 10^(-13.991)
#
# Kinetic reactions
# g) ca2+ + hco3- = h+ + CaCO3(s), A = 0.461 m^2/L, k = 6.456542e-2 mol/m^2 s,
# Keq = 10^(1.8487)
#
# The primary chemical species are h+, hco3- and ca2+. The pressure gradient is fixed,
# and a conservative tracer is also included.
#
# This example is taken from:
# Guo et al, A parallel, fully coupled, fully implicit solution to reactive
# transport in porous media using the preconditioned Jacobian-Free Newton-Krylov
# Method, Advances in Water Resources, 53, 101-108 (2013).
[Mesh]
type = GeneratedMesh
dim = 2
nx = 100
xmax = 1
ymax = 0.25
[]
[Variables]
[./tracer]
[../]
[./ca2+]
[../]
[./h+]
initial_condition = 1.0e-7
scaling = 1e6
[../]
[./hco3-]
[../]
[]
[AuxVariables]
[./pressure]
order = FIRST
family = LAGRANGE
[../]
[]
[ICs]
[./pressure_ic]
type = FunctionIC
variable = pressure
function = pic
[../]
[./hco3_ic]
type = BoundingBoxIC
variable = hco3-
x1 = 0.0
y1 = 0.0
x2 = 1.0e-10
y2 = 0.25
inside = 5.0e-2
outside = 1.0e-6
[../]
[./ca2_ic]
type = BoundingBoxIC
variable = ca2+
x1 = 0.0
y1 = 0.0
x2 = 1.0e-10
y2 = 0.25
inside = 1.0e-6
outside = 5.0e-2
[../]
[./tracer_ic]
type = BoundingBoxIC
variable = tracer
x1 = 0.0
y1 = 0.0
x2 = 1.0e-10
y2 = 0.25
inside = 1.0
outside = 0.0
[../]
[]
[Functions]
[./pic]
type = ParsedFunction
value = 60-50*x
[../]
[]
[ReactionNetwork]
[./AqueousEquilibriumReactions]
primary_species = 'ca2+ hco3- h+'
secondary_species = 'co2_aq co32- caco3_aq cahco3+ caoh+ oh-'
pressure = pressure
reactions = 'h+ + hco3- = co2_aq 6.341,
hco3- - h+ = co32- -10.325,
ca2+ + hco3- - h+ = caco3_aq -7.009,
ca2+ + hco3- = cahco3+ -0.653,
ca2+ - h+ = caoh+ -12.85,
- h+ = oh- -13.991'
[../]
[./SolidKineticReactions]
primary_species = 'ca2+ hco3- h+'
kin_reactions = 'ca2+ + hco3- - h+ = caco3_s'
secondary_species = caco3_s
log10_keq = 1.8487
reference_temperature = 298.15
system_temperature = 298.15
gas_constant = 8.314
specific_reactive_surface_area = 4.61e-4
kinetic_rate_constant = 6.456542e-7
activation_energy = 1.5e4
[../]
[]
[Kernels]
[./tracer_ie]
type = PrimaryTimeDerivative
variable = tracer
[../]
[./tracer_pd]
type = PrimaryDiffusion
variable = tracer
[../]
[./tracer_conv]
type = PrimaryConvection
variable = tracer
p = pressure
[../]
[./ca2+_ie]
type = PrimaryTimeDerivative
variable = ca2+
[../]
[./ca2+_pd]
type = PrimaryDiffusion
variable = ca2+
[../]
[./ca2+_conv]
type = PrimaryConvection
variable = ca2+
p = pressure
[../]
[./h+_ie]
type = PrimaryTimeDerivative
variable = h+
[../]
[./h+_pd]
type = PrimaryDiffusion
variable = h+
[../]
[./h+_conv]
type = PrimaryConvection
variable = h+
p = pressure
[../]
[./hco3-_ie]
type = PrimaryTimeDerivative
variable = hco3-
[../]
[./hco3-_pd]
type = PrimaryDiffusion
variable = hco3-
[../]
[./hco3-_conv]
type = PrimaryConvection
variable = hco3-
p = pressure
[../]
[]
[BCs]
[./tracer_left]
type = DirichletBC
variable = tracer
boundary = left
value = 1.0
[../]
[./tracer_right]
type = ChemicalOutFlowBC
variable = tracer
boundary = right
[../]
[./ca2+_left]
type = SinDirichletBC
variable = ca2+
boundary = left
initial = 5.0e-2
final = 1.0e-6
duration = 1
[../]
[./ca2+_right]
type = ChemicalOutFlowBC
variable = ca2+
boundary = right
[../]
[./hco3-_left]
type = SinDirichletBC
variable = hco3-
boundary = left
initial = 1.0e-6
final = 5.0e-2
duration = 1
[../]
[./hco3-_right]
type = ChemicalOutFlowBC
variable = hco3-
boundary = right
[../]
[./h+_left]
type = DirichletBC
variable = h+
boundary = left
value = 1.0e-7
[../]
[./h+_right]
type = ChemicalOutFlowBC
variable = h+
boundary = right
[../]
[]
[Materials]
[./porous]
type = GenericConstantMaterial
prop_names = 'diffusivity conductivity porosity'
prop_values = '1e-7 2e-4 0.2'
[../]
[]
[Executioner]
type = Transient
solve_type = PJFNK
l_max_its = 50
l_tol = 1e-5
nl_max_its = 10
nl_rel_tol = 1e-5
end_time = 10
[./TimeStepper]
type = ConstantDT
dt = 0.1
[../]
[]
[Preconditioning]
[./smp]
type = SMP
full = true
[../]
[]
[Outputs]
perf_graph = true
exodus = true
[]
```

#### modules/chemical_reactions/test/tests/aqueous_equilibrium/1species_without_action.i

```
# Simple equilibrium reaction example.
# This simulation is identical to 1species.i, but explicitly includes the AuxVariables,
# AuxKernels, and Kernels that the action in 1species.i adds
[Mesh]
type = GeneratedMesh
dim = 2
nx = 10
[]
[Variables]
[./a]
order = FIRST
family = LAGRANGE
[./InitialCondition]
type = BoundingBoxIC
x1 = 0.0
y1 = 0.0
x2 = 1e-2
y2 = 1
inside = 1.0e-2
outside = 1.0e-10
variable = a
[../]
[../]
[]
[AuxVariables]
[./pressure]
order = FIRST
family = LAGRANGE
[../]
[./pa2]
[../]
[]
[AuxKernels]
[./pa2eq]
type = AqueousEquilibriumRxnAux
variable = pa2
v = a
sto_v = 2
log_k = 1
[../]
[]
[ICs]
[./pressure]
type = FunctionIC
variable = pressure
function = 2-x
[../]
[]
[Kernels]
[./a_ie]
type = PrimaryTimeDerivative
variable = a
[../]
[./a_diff]
type = PrimaryDiffusion
variable = a
[../]
[./a_conv]
type = PrimaryConvection
variable = a
p = pressure
[../]
[./aeq]
type = CoupledBEEquilibriumSub
variable = a
log_k = 1
weight = 2
sto_u = 2
[../]
[./adiff]
type = CoupledDiffusionReactionSub
variable = a
log_k = 1
weight = 2
sto_u = 2
[../]
[./aconv]
type = CoupledConvectionReactionSub
variable = a
log_k = 1
weight = 2
sto_u = 2
p = pressure
[../]
[]
[BCs]
[./a_right]
type = ChemicalOutFlowBC
variable = a
boundary = right
[../]
[]
[Materials]
[./porous]
type = GenericConstantMaterial
prop_names = 'diffusivity conductivity porosity'
prop_values = '1e-4 1e-4 0.2'
[../]
[]
[Executioner]
type = Transient
solve_type = PJFNK
petsc_options_iname = '-pc_type -pc_hypre_type'
petsc_options_value = 'hypre boomeramg'
nl_abs_tol = 1e-12
start_time = 0.0
end_time = 100
dt = 10.0
[]
[Outputs]
file_base = 1species_out
exodus = true
perf_graph = true
print_linear_residuals = true
[]
[Preconditioning]
[./smp]
type = SMP
full = true
[../]
[]
```

#### modules/chemical_reactions/test/tests/aqueous_equilibrium/1species.i

```
# Simple equilibrium reaction example to illustrate the use of the AqueousEquilibriumReactions
# action.
# In this example, a single primary species a is transported by diffusion and convection
# from the left of the porous medium, reacting to form an equilibrium species pa2 according to
# the equilibrium reaction specified in the AqueousEquilibriumReactions block as:
#
# reactions = '2a = pa2 1'
#
# where the 2 is the weight of the equilibrium species, and the 1 refers to the equilibrium
# constant (log10(Keq) = 1).
#
# The AqueousEquilibriumReactions action creates all the required kernels and auxkernels
# to compute the reaction given by the above equilibrium reaction equation.
#
# Specifically, it adds to following:
# * An AuxVariable named 'pa2' (given in the reactions equations)
# * A AqueousEquilibriumRxnAux AuxKernel for this AuxVariable with all parameters
# * A CoupledBEEquilibriumSub Kernel for each primary species with all parameters
# * A CoupledDiffusionReactionSub Kernel for each primary species with all parameters
# * A CoupledConvectionReactionSub Kernel for each primary species with all parameters if
# pressure is a coupled variable
[Mesh]
type = GeneratedMesh
dim = 2
nx = 10
[]
[Variables]
[./a]
order = FIRST
family = LAGRANGE
[./InitialCondition]
type = BoundingBoxIC
x1 = 0.0
y1 = 0.0
x2 = 1e-2
y2 = 1
inside = 1.0e-2
outside = 1.0e-10
variable = a
[../]
[../]
[]
[AuxVariables]
[./pressure]
order = FIRST
family = LAGRANGE
[../]
[]
[ICs]
[./pressure]
type = FunctionIC
variable = pressure
function = 2-x
[../]
[]
[ReactionNetwork]
[./AqueousEquilibriumReactions]
primary_species = a
reactions = '2a = pa2 1'
secondary_species = pa2
pressure = pressure
[../]
[]
[Kernels]
[./a_ie]
type = PrimaryTimeDerivative
variable = a
[../]
[./a_diff]
type = PrimaryDiffusion
variable = a
[../]
[./a_conv]
type = PrimaryConvection
variable = a
p = pressure
[../]
[]
[BCs]
[./a_right]
type = ChemicalOutFlowBC
variable = a
boundary = right
[../]
[]
[Materials]
[./porous]
type = GenericConstantMaterial
prop_names = 'diffusivity conductivity porosity'
prop_values = '1e-4 1e-4 0.2'
[../]
[]
[Executioner]
type = Transient
solve_type = PJFNK
petsc_options_iname = '-pc_type -pc_hypre_type'
petsc_options_value = 'hypre boomeramg'
nl_abs_tol = 1e-12
start_time = 0.0
end_time = 100
dt = 10.0
[]
[Outputs]
file_base = 1species_out
exodus = true
perf_graph = true
print_linear_residuals = true
[]
[Preconditioning]
[./smp]
type = SMP
full = true
[../]
[]
```

#### modules/chemical_reactions/test/tests/parser/equilibrium_action.i

```
# Test AqueousEquilibriumReactions parser
[Mesh]
type = GeneratedMesh
dim = 2
[]
[Variables]
[./a]
[../]
[./b]
[../]
[]
[AuxVariables]
[./pressure]
[../]
[]
[ICs]
[./a]
type = BoundingBoxIC
variable = a
x1 = 0.0
y1 = 0.0
x2 = 1.0e-10
y2 = 1
inside = 1.0e-2
outside = 1.0e-10
[../]
[./b]
type = BoundingBoxIC
variable = b
x1 = 0.0
y1 = 0.0
x2 = 1.0e-10
y2 = 1
inside = 1.0e-2
outside = 1.0e-10
[../]
[./pressure]
type = FunctionIC
variable = pressure
function = 2-x
[../]
[]
[ReactionNetwork]
[./AqueousEquilibriumReactions]
primary_species = 'a b'
reactions = '2a = pa2 2,
(1.0)a + (1.0)b = pab -2'
secondary_species = 'pa2 pab'
pressure = pressure
[../]
[]
[Kernels]
[./a_ie]
type = PrimaryTimeDerivative
variable = a
[../]
[./a_diff]
type = PrimaryDiffusion
variable = a
[../]
[./a_conv]
type = PrimaryConvection
variable = a
p = pressure
[../]
[./b_ie]
type = PrimaryTimeDerivative
variable = b
[../]
[./b_diff]
type = PrimaryDiffusion
variable = b
[../]
[./b_conv]
type = PrimaryConvection
variable = b
p = pressure
[../]
[]
[BCs]
[./a_left]
type = DirichletBC
variable = a
boundary = left
value = 1.0e-2
[../]
[./a_right]
type = ChemicalOutFlowBC
variable = a
boundary = right
[../]
[./b_left]
type = DirichletBC
variable = b
boundary = left
value = 1.0e-2
[../]
[./b_right]
type = ChemicalOutFlowBC
variable = b
boundary = right
[../]
[]
[Materials]
[./porous]
type = GenericConstantMaterial
prop_names = 'diffusivity conductivity porosity'
prop_values = '1e-4 1e-4 0.2'
[../]
[]
[Executioner]
type = Transient
solve_type = PJFNK
nl_abs_tol = 1e-12
end_time = 10
dt = 10
[]
[Outputs]
file_base = equilibrium_out
exodus = true
perf_graph = true
print_linear_residuals = true
[]
[Preconditioning]
[./smp]
type = SMP
full = true
[../]
[]
```

#### modules/chemical_reactions/test/tests/aqueous_equilibrium/2species_without_action.i

```
# Simple equilibrium reaction example to illustrate the use of the AqueousEquilibriumReactions
# action.
# In this example, two primary species a and b are transported by diffusion and convection
# from the left of the porous medium, reacting to form two equilibrium species pa2 and pab
# according to the equilibrium reaction specified in the AqueousEquilibriumReactions block as:
#
# reactions = '2a = pa2 2
# a + b = pab -2'
#
# where the 2 is the weight of the equilibrium species, the 2 on the RHS of the first reaction
# refers to the equilibrium constant (log10(Keq) = 2), and the -2 on the RHS of the second
# reaction equates to log10(Keq) = -2.
#
# This example is identical to 2species.i, except that it explicitly includes all AuxKernels
# and Kernels that are set up by the action in 2species.i
[Mesh]
type = GeneratedMesh
dim = 2
nx = 10
[]
[Variables]
[./a]
order = FIRST
family = LAGRANGE
[./InitialCondition]
type = BoundingBoxIC
x1 = 0.0
y1 = 0.0
x2 = 1.0e-10
y2 = 1
inside = 1.0e-2
outside = 1.0e-10
[../]
[../]
[./b]
order = FIRST
family = LAGRANGE
[./InitialCondition]
type = BoundingBoxIC
x1 = 0.0
y1 = 0.0
x2 = 1.0e-10
y2 = 1
inside = 1.0e-2
outside = 1.0e-10
[../]
[../]
[]
[AuxVariables]
[./pressure]
order = FIRST
family = LAGRANGE
[../]
[./pa2]
[../]
[./pab]
[../]
[]
[AuxKernels]
[./pa2eq]
type = AqueousEquilibriumRxnAux
variable = pa2
v = a
sto_v = 2
log_k = 2
[../]
[./pabeq]
type = AqueousEquilibriumRxnAux
variable = pab
v = 'a b'
sto_v = '1 1'
log_k = -2
[../]
[]
[ICs]
[./pressure]
type = FunctionIC
variable = pressure
function = 2-x
[../]
[]
[Kernels]
[./a_ie]
type = PrimaryTimeDerivative
variable = a
[../]
[./a_diff]
type = PrimaryDiffusion
variable = a
[../]
[./a_conv]
type = PrimaryConvection
variable = a
p = pressure
[../]
[./b_ie]
type = PrimaryTimeDerivative
variable = b
[../]
[./b_diff]
type = PrimaryDiffusion
variable = b
[../]
[./b_conv]
type = PrimaryConvection
variable = b
p = pressure
[../]
[./a1eq]
type = CoupledBEEquilibriumSub
variable = a
log_k = 2
weight = 2
sto_u = 2
[../]
[./a1diff]
type = CoupledDiffusionReactionSub
variable = a
log_k = 2
weight = 2
sto_u = 2
[../]
[./a1conv]
type = CoupledConvectionReactionSub
variable = a
log_k = 2
weight = 2
sto_u = 2
p = pressure
[../]
[./a2eq]
type = CoupledBEEquilibriumSub
variable = a
v = b
log_k = -2
weight = 1
sto_v = 1
sto_u = 1
[../]
[./a2diff]
type = CoupledDiffusionReactionSub
variable = a
v = b
log_k = -2
weight = 1
sto_v = 1
sto_u = 1
[../]
[./a2conv]
type = CoupledConvectionReactionSub
variable = a
v = b
log_k = -2
weight = 1
sto_v = 1
sto_u = 1
p = pressure
[../]
[./b2eq]
type = CoupledBEEquilibriumSub
variable = b
v = a
log_k = -2
weight = 1
sto_v = 1
sto_u = 1
[../]
[./b2diff]
type = CoupledDiffusionReactionSub
variable = b
v = a
log_k = -2
weight = 1
sto_v = 1
sto_u = 1
[../]
[./b2conv]
type = CoupledConvectionReactionSub
variable = b
v = a
log_k = -2
weight = 1
sto_v = 1
sto_u = 1
p = pressure
[../]
[]
[BCs]
[./a_left]
type = DirichletBC
variable = a
boundary = left
value = 1.0e-2
[../]
[./a_right]
type = ChemicalOutFlowBC
variable = a
boundary = right
[../]
[./b_left]
type = DirichletBC
variable = b
boundary = left
value = 1.0e-2
[../]
[./b_right]
type = ChemicalOutFlowBC
variable = b
boundary = right
[../]
[]
[Materials]
[./porous]
type = GenericConstantMaterial
prop_names = 'diffusivity conductivity porosity'
prop_values = '1e-4 1e-4 0.2'
[../]
[]
[Executioner]
type = Transient
solve_type = PJFNK
petsc_options_iname = '-pc_type -pc_hypre_type'
petsc_options_value = 'hypre boomeramg'
nl_abs_tol = 1e-12
start_time = 0.0
end_time = 100
dt = 10.0
[]
[Outputs]
file_base = 2species_out
exodus = true
perf_graph = true
print_linear_residuals = true
[]
[Preconditioning]
[./smp]
type = SMP
full = true
[../]
[]
```

#### modules/chemical_reactions/test/tests/aqueous_equilibrium/2species_with_density.i

```
# Simple equilibrium reaction example with fluid density and gravity included
# in calculation of the Darcy velocity. For details about reaction network,
# see documentation in 2species.i
[Mesh]
type = GeneratedMesh
dim = 2
nx = 10
[]
[Variables]
[./a]
order = FIRST
family = LAGRANGE
[./InitialCondition]
type = BoundingBoxIC
x1 = 0.0
y1 = 0.0
x2 = 1.0e-10
y2 = 1
inside = 1.0e-2
outside = 1.0e-10
[../]
[../]
[./b]
order = FIRST
family = LAGRANGE
[./InitialCondition]
type = BoundingBoxIC
x1 = 0.0
y1 = 0.0
x2 = 1.0e-10
y2 = 1
inside = 1.0e-2
outside = 1.0e-10
[../]
[../]
[./pressure]
order = FIRST
family = LAGRANGE
initial_condition = 1
[../]
[]
[ReactionNetwork]
[./AqueousEquilibriumReactions]
primary_species = 'a b'
reactions = '2a = pa2 2,
a + b = pab -2'
secondary_species = 'pa2 pab'
pressure = pressure
gravity = '-1 0 0'
[../]
[]
[Kernels]
[./a_ie]
type = PrimaryTimeDerivative
variable = a
[../]
[./a_diff]
type = PrimaryDiffusion
variable = a
[../]
[./a_conv]
type = PrimaryConvection
variable = a
p = pressure
gravity = '-1 0 0'
[../]
[./b_ie]
type = PrimaryTimeDerivative
variable = b
[../]
[./b_diff]
type = PrimaryDiffusion
variable = b
[../]
[./b_conv]
type = PrimaryConvection
variable = b
p = pressure
gravity = '-1 0 0'
[../]
[./p]
type = DarcyFluxPressure
variable = pressure
gravity = '-1 0 0'
[../]
[]
[BCs]
[./a_left]
type = DirichletBC
variable = a
boundary = left
value = 1.0e-2
[../]
[./a_right]
type = ChemicalOutFlowBC
variable = a
boundary = right
[../]
[./b_left]
type = DirichletBC
variable = b
boundary = left
value = 1.0e-2
[../]
[./b_right]
type = ChemicalOutFlowBC
variable = b
boundary = right
[../]
[./pleft]
type = DirichletBC
variable = pressure
value = 2
boundary = left
[../]
[./pright]
type = DirichletBC
variable = pressure
value = 1
boundary = right
[../]
[]
[Materials]
[./porous]
type = GenericConstantMaterial
prop_names = 'diffusivity conductivity porosity density'
prop_values = '1e-4 1e-4 0.2 4'
[../]
[]
[Executioner]
type = Transient
solve_type = PJFNK
petsc_options_iname = '-pc_type -pc_hypre_type'
petsc_options_value = 'hypre boomeramg'
nl_abs_tol = 1e-12
start_time = 0.0
end_time = 100
dt = 10.0
[]
[Outputs]
exodus = true
perf_graph = true
print_linear_residuals = true
[]
[Preconditioning]
[./smp]
type = SMP
full = true
[../]
[]
```

#### modules/chemical_reactions/test/tests/aqueous_equilibrium/2species_eqaux.i

```
# In this example, two primary species a and b are transported by diffusion and convection
# from the left of the porous medium, reacting to form two equilibrium species pa2 and pab
# according to the equilibrium reaction specified in the AqueousEquilibriumReactions block as:
#
# reactions = '2a = pa2 2
# a + b = pab -2'
#
# where the 2 is the weight of the equilibrium species, the 2 on the RHS of the first reaction
# refers to the equilibrium constant (log10(Keq) = 2), and the -2 on the RHS of the second
# reaction equates to log10(Keq) = -2.
#
# This example is identical to 2species.i, except that it explicitly includes all AuxKernels
# and Kernels that are set up by the action in 2species.i, and that the equilbrium constants
# are provided by AuxVariables
[Mesh]
type = GeneratedMesh
dim = 2
nx = 10
[]
[Variables]
[./a]
order = FIRST
family = LAGRANGE
[./InitialCondition]
type = BoundingBoxIC
x1 = 0.0
y1 = 0.0
x2 = 1.0e-10
y2 = 1
inside = 1.0e-2
outside = 1.0e-10
[../]
[../]
[./b]
order = FIRST
family = LAGRANGE
[./InitialCondition]
type = BoundingBoxIC
x1 = 0.0
y1 = 0.0
x2 = 1.0e-10
y2 = 1
inside = 1.0e-2
outside = 1.0e-10
[../]
[../]
[]
[AuxVariables]
[./pressure]
order = FIRST
family = LAGRANGE
[../]
[./pa2]
[../]
[./pab]
[../]
[./pa2_logk]
initial_condition = 2
[../]
[./pab_logk]
initial_condition = -2
[../]
[]
[AuxKernels]
[./pa2eq]
type = AqueousEquilibriumRxnAux
variable = pa2
v = a
sto_v = 2
log_k = pa2_logk
[../]
[./pabeq]
type = AqueousEquilibriumRxnAux
variable = pab
v = 'a b'
sto_v = '1 1'
log_k = pab_logk
[../]
[]
[ICs]
[./pressure]
type = FunctionIC
variable = pressure
function = 2-x
[../]
[]
[Kernels]
[./a_ie]
type = PrimaryTimeDerivative
variable = a
[../]
[./a_diff]
type = PrimaryDiffusion
variable = a
[../]
[./a_conv]
type = PrimaryConvection
variable = a
p = pressure
[../]
[./b_ie]
type = PrimaryTimeDerivative
variable = b
[../]
[./b_diff]
type = PrimaryDiffusion
variable = b
[../]
[./b_conv]
type = PrimaryConvection
variable = b
p = pressure
[../]
[./a1eq]
type = CoupledBEEquilibriumSub
variable = a
log_k = pa2_logk
weight = 2
sto_u = 2
[../]
[./a1diff]
type = CoupledDiffusionReactionSub
variable = a
log_k = pa2_logk
weight = 2
sto_u = 2
[../]
[./a1conv]
type = CoupledConvectionReactionSub
variable = a
log_k = pa2_logk
weight = 2
sto_u = 2
p = pressure
[../]
[./a2eq]
type = CoupledBEEquilibriumSub
variable = a
v = b
log_k = pab_logk
weight = 1
sto_v = 1
sto_u = 1
[../]
[./a2diff]
type = CoupledDiffusionReactionSub
variable = a
v = b
log_k = pab_logk
weight = 1
sto_v = 1
sto_u = 1
[../]
[./a2conv]
type = CoupledConvectionReactionSub
variable = a
v = b
log_k = pab_logk
weight = 1
sto_v = 1
sto_u = 1
p = pressure
[../]
[./b2eq]
type = CoupledBEEquilibriumSub
variable = b
v = a
log_k = pab_logk
weight = 1
sto_v = 1
sto_u = 1
[../]
[./b2diff]
type = CoupledDiffusionReactionSub
variable = b
v = a
log_k = pab_logk
weight = 1
sto_v = 1
sto_u = 1
[../]
[./b2conv]
type = CoupledConvectionReactionSub
variable = b
v = a
log_k = pab_logk
weight = 1
sto_v = 1
sto_u = 1
p = pressure
[../]
[]
[BCs]
[./a_left]
type = DirichletBC
variable = a
boundary = left
value = 1.0e-2
[../]
[./a_right]
type = ChemicalOutFlowBC
variable = a
boundary = right
[../]
[./b_left]
type = DirichletBC
variable = b
boundary = left
value = 1.0e-2
[../]
[./b_right]
type = ChemicalOutFlowBC
variable = b
boundary = right
[../]
[]
[Materials]
[./porous]
type = GenericConstantMaterial
prop_names = 'diffusivity conductivity porosity'
prop_values = '1e-4 1e-4 0.2'
[../]
[]
[Executioner]
type = Transient
solve_type = PJFNK
petsc_options_iname = '-pc_type -pc_hypre_type'
petsc_options_value = 'hypre boomeramg'
nl_abs_tol = 1e-12
start_time = 0.0
end_time = 100
dt = 10.0
[]
[Outputs]
file_base = 2species_out
exodus = true
perf_graph = true
print_linear_residuals = true
hide = 'pa2_logk pab_logk'
[]
[Preconditioning]
[./smp]
type = SMP
full = true
[../]
[]
```

#### modules/chemical_reactions/test/tests/aqueous_equilibrium/2species.i

```
# Simple equilibrium reaction example to illustrate the use of the AqueousEquilibriumReactions
# action.
# In this example, two primary species a and b are transported by diffusion and convection
# from the left of the porous medium, reacting to form two equilibrium species pa2 and pab
# according to the equilibrium reaction specified in the AqueousEquilibriumReactions block as:
#
# reactions = '2a = pa2 2
# a + b = pab -2'
#
# where the 2 is the weight of the equilibrium species, the 2 on the RHS of the first reaction
# refers to the equilibrium constant (log10(Keq) = 2), and the -2 on the RHS of the second
# reaction equates to log10(Keq) = -2.
#
# The AqueousEquilibriumReactions action creates all the required kernels and auxkernels
# to compute the reaction given by the above equilibrium reaction equation.
#
# Specifically, it adds to following:
# * An AuxVariable named 'pa2' (given in the reactions equations)
# * An AuxVariable named 'pab' (given in the reactions equations)
# * A AqueousEquilibriumRxnAux AuxKernel for each AuxVariable with all parameters
# * A CoupledBEEquilibriumSub Kernel for each primary species with all parameters
# * A CoupledDiffusionReactionSub Kernel for each primary species with all parameters
# * A CoupledConvectionReactionSub Kernel for each primary species with all parameters if
# pressure is a coupled variable
[Mesh]
type = GeneratedMesh
dim = 2
nx = 10
[]
[Variables]
[./a]
order = FIRST
family = LAGRANGE
[./InitialCondition]
type = BoundingBoxIC
x1 = 0.0
y1 = 0.0
x2 = 1.0e-10
y2 = 1
inside = 1.0e-2
outside = 1.0e-10
[../]
[../]
[./b]
order = FIRST
family = LAGRANGE
[./InitialCondition]
type = BoundingBoxIC
x1 = 0.0
y1 = 0.0
x2 = 1.0e-10
y2 = 1
inside = 1.0e-2
outside = 1.0e-10
[../]
[../]
[]
[AuxVariables]
[./pressure]
order = FIRST
family = LAGRANGE
[../]
[]
[ICs]
[./pressure]
type = FunctionIC
variable = pressure
function = 2-x
[../]
[]
[ReactionNetwork]
[./AqueousEquilibriumReactions]
primary_species = 'a b'
reactions = '2a = pa2 2,
a + b = pab -2'
secondary_species = 'pa2 pab'
pressure = pressure
[../]
[]
[Kernels]
[./a_ie]
type = PrimaryTimeDerivative
variable = a
[../]
[./a_diff]
type = PrimaryDiffusion
variable = a
[../]
[./a_conv]
type = PrimaryConvection
variable = a
p = pressure
[../]
[./b_ie]
type = PrimaryTimeDerivative
variable = b
[../]
[./b_diff]
type = PrimaryDiffusion
variable = b
[../]
[./b_conv]
type = PrimaryConvection
variable = b
p = pressure
[../]
[]
[BCs]
[./a_left]
type = DirichletBC
variable = a
boundary = left
value = 1.0e-2
[../]
[./a_right]
type = ChemicalOutFlowBC
variable = a
boundary = right
[../]
[./b_left]
type = DirichletBC
variable = b
boundary = left
value = 1.0e-2
[../]
[./b_right]
type = ChemicalOutFlowBC
variable = b
boundary = right
[../]
[]
[Materials]
[./porous]
type = GenericConstantMaterial
prop_names = 'diffusivity conductivity porosity'
prop_values = '1e-4 1e-4 0.2'
[../]
[]
[Executioner]
type = Transient
solve_type = PJFNK
petsc_options_iname = '-pc_type -pc_hypre_type'
petsc_options_value = 'hypre boomeramg'
nl_abs_tol = 1e-12
start_time = 0.0
end_time = 100
dt = 10.0
[]
[Outputs]
file_base = 2species_out
exodus = true
perf_graph = true
print_linear_residuals = true
[]
[Preconditioning]
[./smp]
type = SMP
full = true
[../]
[]
```