Pressure-pulses in 1D

The PorousFlow fluid equation for single-phase flow through a fully saturated medium without gravity and without sources is just Darcy's equation $var element = document.getElementById("moose-equation-ab24f499-1d55-4be9-be7a-e05a94f94548");katex.render("\\frac{\\partial}{\\partial t}\\phi\\rho = \\nabla_{i}\\left(\\frac{\\rho \\kappa_{ij}}{\\mu} \\nabla_{j}P \\right) \\ ,", element, {displayMode:true,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ with notation described in the governing equations. Using $var element = document.getElementById("moose-equation-e38da253-90c0-4b83-90dc-a800716c10bc");katex.render("\\rho \\propto \\exp(P/K)", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ , where $var element = document.getElementById("moose-equation-b923d410-cd07-4872-850d-77db26e08085");katex.render("K", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ is the fluid bulk modulus, Darcy's equation becomes $var element = document.getElementById("moose-equation-065eb1f8-d424-40fb-8b2c-28434ca6df57");katex.render("\\frac{\\partial}{\\partial t}\\rho = \\nabla_{i}\\alpha_{ij}\\nabla\\rho \\ ,", element, {displayMode:true,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ with $var element = document.getElementById("moose-equation-b8319a15-94ae-49fe-a31a-4a13360746f3");katex.render("\\alpha_{ij} = \\frac{\\kappa_{ij}B}{\\mu\\phi} \\ .", element, {displayMode:true,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ Here I've assumed the porosity and bulk modulus are constant in space and time.

Consider the one-dimensional case were the spatial dimension is the semi-infinite line $var element = document.getElementById("moose-equation-9a228002-8549-4c6d-acb5-24759d1fac06");katex.render("x\\geq 0", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ . Suppose that initially the pressure is constant, so that $var element = document.getElementById("moose-equation-90f43961-d749-4c25-8585-876143bf1a2f");katex.render("\\rho(x, t=0) = \\rho_{0} \\ \\ \\ \\mathrm{for }\\ \\ x\\geq 0 \\ .", element, {displayMode:true,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ Then apply a fixed-pressure Dirichlet boundary condition at $var element = document.getElementById("moose-equation-d03bd846-7d72-4543-816c-2489f5fc1daf");katex.render("x=0", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ so that $var element = document.getElementById("moose-equation-9ec12eca-c055-4146-b0b8-f516917c3e01");katex.render("\\rho(x=0, t>0) = \\rho_{\\infty}", element, {displayMode:true,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ The solution of the above differential equation is well known to be $(1)var element = document.getElementById("moose-equation-a4595eba-f77f-4b49-b44b-34a64ad7a078");katex.render("\\rho(x, t) = \\rho_{\\infty} + (\\rho_{0} - \\rho_{\\infty})\\,\\mathrm{Erf}\\left( \\frac{x}{\\sqrt{4\\alpha t}} \\right) \\ , ", element, {displayMode:true,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ where Erf is the error function.

A number of PorousFlow tests verify that this solution is produced with parameters shown in Table 1

Table 1: Parameter values used in the pressure-pulse tests

Parameter	Value
length of 1D bar	100 m
number of elements	10
end time (for transient simulations)	10000 s
number of time steps	10
Fluid bulk modulus ( $var element = document.getElementById("moose-equation-24ff7cc4-bda3-439b-a32b-17181369db56");katex.render("B", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ )	2 GPa
Fluid viscosity ( $var element = document.getElementById("moose-equation-736d2fc9-0af9-4198-9170-f489575c2b81");katex.render("\\mu", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ )	0.001 Pa.s
Permeability ( $var element = document.getElementById("moose-equation-78add6a4-be1c-4fe1-8ce3-7fab4a0c2b0c");katex.render("\\kappa_{xx}", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ )	$var element = document.getElementById("moose-equation-2e8b9534-eb4e-46d1-b1aa-ad95d3017dfa");katex.render("10^{-15}\\,", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ m $var element = document.getElementById("moose-equation-b6090d5a-3eda-4085-b17f-24f883411a7f");katex.render("^{2}", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$
Porosity	0.1
Initial pressure	2 MPa
Applied pressure	3 MPa

The tests include:

Steady state 1-phase analysis to demonstrate that the steady-state of $var element = document.getElementById("moose-equation-3c8bb98d-c3ce-42cd-927e-929e0933959a");katex.render("\\rho = \\rho_{\\infty}", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ is achieved.

# Pressure pulse in 1D with 1 phase - steady
# This file employs the PorousFlowFullySaturated Action.  For the non-Action version see pressure_pulse_1d.i
[Mesh<<<{"href": "../../../../syntax/Mesh/index.html"}>>>]
  type = GeneratedMesh
  dim = 1
  nx = 10
  xmin = 0
  xmax = 100
[]

[GlobalParams<<<{"href": "../../../../syntax/GlobalParams/index.html"}>>>]
  PorousFlowDictator = dictator
[]

[Variables<<<{"href": "../../../../syntax/Variables/index.html"}>>>]
  [pp]
    initial_condition<<<{"description": "Specifies a constant initial condition for this variable"}>>> = 2E6
  []
[]

[PorousFlowFullySaturated<<<{"href": "../../../../syntax/PorousFlowFullySaturated/index.html"}>>>]
  porepressure<<<{"description": "The name of the porepressure variable"}>>> = pp
  gravity<<<{"description": "Gravitational acceleration vector downwards (m/s^2)"}>>> = '0 0 0'
  fp<<<{"description": "The name of the user object for fluid properties. Only needed if fluid_properties_type = PorousFlowSingleComponentFluid"}>>> = simple_fluid
  stabilization<<<{"description": "Numerical stabilization used.  'Full' means full upwinding.  'KT' means FEM-TVD stabilization of Kuzmin-Turek"}>>> = Full
[]

[FluidProperties<<<{"href": "../../../../syntax/FluidProperties/index.html"}>>>]
  [simple_fluid]
    type = SimpleFluidProperties<<<{"description": "Fluid properties for a simple fluid with a constant bulk density", "href": "../../../../source/fluidproperties/SimpleFluidProperties.html"}>>>
    bulk_modulus<<<{"description": "Constant bulk modulus (Pa)"}>>> = 2e9
    density0<<<{"description": "Density at zero pressure and zero temperature"}>>> = 1000
    thermal_expansion<<<{"description": "Constant coefficient of thermal expansion (1/K)"}>>> = 0
    viscosity<<<{"description": "Constant dynamic viscosity (Pa.s)"}>>> = 1e-3
  []
[]

[Materials<<<{"href": "../../../../syntax/Materials/index.html"}>>>]
  [permeability]
    type = PorousFlowPermeabilityConst<<<{"description": "This Material calculates the permeability tensor assuming it is constant", "href": "../../../../source/materials/PorousFlowPermeabilityConst.html"}>>>
    permeability<<<{"description": "The permeability tensor (usually in m^2), which is assumed constant for this material"}>>> = '1E-15 0 0 0 1E-15 0 0 0 1E-15'
  []
[]

[BCs<<<{"href": "../../../../syntax/BCs/index.html"}>>>]
  [left]
    type = DirichletBC<<<{"description": "Imposes the essential boundary condition $u=g$, where $g$ is a constant, controllable value.", "href": "../../../../source/bcs/DirichletBC.html"}>>>
    boundary<<<{"description": "The list of boundary IDs from the mesh where this object applies"}>>> = left
    value<<<{"description": "Value of the BC"}>>> = 3E6
    variable<<<{"description": "The name of the variable that this residual object operates on"}>>> = pp
  []
[]

[Preconditioning<<<{"href": "../../../../syntax/Preconditioning/index.html"}>>>]
  [andy]
    type = SMP<<<{"description": "Single matrix preconditioner (SMP) builds a preconditioner using user defined off-diagonal parts of the Jacobian.", "href": "../../../../source/preconditioners/SingleMatrixPreconditioner.html"}>>>
    full<<<{"description": "Set to true if you want the full set of couplings between variables simply for convenience so you don't have to set every off_diag_row and off_diag_column combination."}>>> = true
  []
[]

[Executioner<<<{"href": "../../../../syntax/Executioner/index.html"}>>>]
  type = Steady
  solve_type = Newton
[]

[Postprocessors<<<{"href": "../../../../syntax/Postprocessors/index.html"}>>>]
  [p000]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '0 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p010]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '10 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p020]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '20 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p030]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '30 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p040]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '40 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p050]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '50 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p060]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '60 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p070]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '70 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p080]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '80 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p090]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '90 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p100]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '100 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
[]

[Outputs<<<{"href": "../../../../syntax/Outputs/index.html"}>>>]
  file_base<<<{"description": "Common file base name to be utilized with all output objects"}>>> = pressure_pulse_1d_steady
  print_linear_residuals<<<{"description": "Enable printing of linear residuals to the screen (Console)"}>>> = false
  csv<<<{"description": "Output the scalar variable and postprocessors to a *.csv file using the default CSV output."}>>> = true
[]

Transient 1-phase analysis.

# Pressure pulse in 1D with 1 phase - transient
# This input file uses the PorousFlowFullySaturated Action.  For the non-Action version, see pressure_pulse_1d.i
[Mesh<<<{"href": "../../../../syntax/Mesh/index.html"}>>>]
  type = GeneratedMesh
  dim = 1
  nx = 10
  xmin = 0
  xmax = 100
[]

[GlobalParams<<<{"href": "../../../../syntax/GlobalParams/index.html"}>>>]
  PorousFlowDictator = dictator
[]

[Variables<<<{"href": "../../../../syntax/Variables/index.html"}>>>]
  [pp]
    initial_condition<<<{"description": "Specifies a constant initial condition for this variable"}>>> = 2E6
  []
[]

[PorousFlowFullySaturated<<<{"href": "../../../../syntax/PorousFlowFullySaturated/index.html"}>>>]
  porepressure<<<{"description": "The name of the porepressure variable"}>>> = pp
  gravity<<<{"description": "Gravitational acceleration vector downwards (m/s^2)"}>>> = '0 0 0'
  fp<<<{"description": "The name of the user object for fluid properties. Only needed if fluid_properties_type = PorousFlowSingleComponentFluid"}>>> = simple_fluid
  stabilization<<<{"description": "Numerical stabilization used.  'Full' means full upwinding.  'KT' means FEM-TVD stabilization of Kuzmin-Turek"}>>> = Full
[]

[FluidProperties<<<{"href": "../../../../syntax/FluidProperties/index.html"}>>>]
  [simple_fluid]
    type = SimpleFluidProperties<<<{"description": "Fluid properties for a simple fluid with a constant bulk density", "href": "../../../../source/fluidproperties/SimpleFluidProperties.html"}>>>
    bulk_modulus<<<{"description": "Constant bulk modulus (Pa)"}>>> = 2e9
    density0<<<{"description": "Density at zero pressure and zero temperature"}>>> = 1000
    thermal_expansion<<<{"description": "Constant coefficient of thermal expansion (1/K)"}>>> = 0
    viscosity<<<{"description": "Constant dynamic viscosity (Pa.s)"}>>> = 1e-3
  []
[]

[Materials<<<{"href": "../../../../syntax/Materials/index.html"}>>>]
  [porosity]
    type = PorousFlowPorosityConst<<<{"description": "This Material calculates the porosity assuming it is constant", "href": "../../../../source/materials/PorousFlowPorosityConst.html"}>>>
    porosity<<<{"description": "The porosity (assumed indepenent of porepressure, temperature, strain, etc, for this material).  This should be a real number, or a constant monomial variable (not a linear lagrange or other kind of variable)."}>>> = 0.1
  []
  [permeability]
    type = PorousFlowPermeabilityConst<<<{"description": "This Material calculates the permeability tensor assuming it is constant", "href": "../../../../source/materials/PorousFlowPermeabilityConst.html"}>>>
    permeability<<<{"description": "The permeability tensor (usually in m^2), which is assumed constant for this material"}>>> = '1E-15 0 0 0 1E-15 0 0 0 1E-15'
  []
[]

[BCs<<<{"href": "../../../../syntax/BCs/index.html"}>>>]
  [left]
    type = DirichletBC<<<{"description": "Imposes the essential boundary condition $u=g$, where $g$ is a constant, controllable value.", "href": "../../../../source/bcs/DirichletBC.html"}>>>
    boundary<<<{"description": "The list of boundary IDs from the mesh where this object applies"}>>> = left
    value<<<{"description": "Value of the BC"}>>> = 3E6
    variable<<<{"description": "The name of the variable that this residual object operates on"}>>> = pp
  []
[]

[Preconditioning<<<{"href": "../../../../syntax/Preconditioning/index.html"}>>>]
  [andy]
    type = SMP<<<{"description": "Single matrix preconditioner (SMP) builds a preconditioner using user defined off-diagonal parts of the Jacobian.", "href": "../../../../source/preconditioners/SingleMatrixPreconditioner.html"}>>>
    full<<<{"description": "Set to true if you want the full set of couplings between variables simply for convenience so you don't have to set every off_diag_row and off_diag_column combination."}>>> = true
  []
[]

[Executioner<<<{"href": "../../../../syntax/Executioner/index.html"}>>>]
  type = Transient
  solve_type = Newton
  dt = 1E3
  end_time = 1E4
[]

[Postprocessors<<<{"href": "../../../../syntax/Postprocessors/index.html"}>>>]
  [p000]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '0 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p010]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '10 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p020]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '20 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p030]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '30 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p040]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '40 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p050]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '50 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p060]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '60 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p070]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '70 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p080]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '80 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p090]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '90 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p100]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '100 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
[]

[Outputs<<<{"href": "../../../../syntax/Outputs/index.html"}>>>]
  file_base<<<{"description": "Common file base name to be utilized with all output objects"}>>> = pressure_pulse_1d
  print_linear_residuals<<<{"description": "Enable printing of linear residuals to the screen (Console)"}>>> = false
  csv<<<{"description": "Output the scalar variable and postprocessors to a *.csv file using the default CSV output."}>>> = true
[]

Transient 1-phase, 3 component analysis to check that the components diffuse at the same rate.

# Pressure pulse in 1D with 1 phase but 3 components (viscosity, relperm, etc are independent of mass-fractions) - transient
# This input file uses the PorousFlowFullySaturated Action.  For the non-Action version, see pressure_pulse_1d_3comp.i
[Mesh<<<{"href": "../../../../syntax/Mesh/index.html"}>>>]
  type = GeneratedMesh
  dim = 1
  nx = 10
  xmin = 0
  xmax = 100
[]

[GlobalParams<<<{"href": "../../../../syntax/GlobalParams/index.html"}>>>]
  PorousFlowDictator = dictator
[]

[Variables<<<{"href": "../../../../syntax/Variables/index.html"}>>>]
  [pp]
    initial_condition<<<{"description": "Specifies a constant initial condition for this variable"}>>> = 2E6
  []
  [massfrac0]
    initial_condition<<<{"description": "Specifies a constant initial condition for this variable"}>>> = 0.1
  []
  [massfrac1]
    initial_condition<<<{"description": "Specifies a constant initial condition for this variable"}>>> = 0.3
  []
[]

[PorousFlowFullySaturated<<<{"href": "../../../../syntax/PorousFlowFullySaturated/index.html"}>>>]
  porepressure<<<{"description": "The name of the porepressure variable"}>>> = pp
  mass_fraction_vars<<<{"description": "List of variables that represent the mass fractions.  With only one fluid component, this may be left empty.  With N fluid components, the format is 'f_0 f_1 f_2 ... f_(N-1)'.  That is, the N^th component need not be specified because f_N = 1 - (f_0 + f_1 + ... + f_(N-1)).  It is best numerically to choose the N-1 mass fraction variables so that they represent the fluid components with small concentrations.  This Action will associated the i^th mass fraction variable to the equation for the i^th fluid component, and the pressure variable to the N^th fluid component."}>>> = 'massfrac0 massfrac1'
  gravity<<<{"description": "Gravitational acceleration vector downwards (m/s^2)"}>>> = '0 0 0'
  fp<<<{"description": "The name of the user object for fluid properties. Only needed if fluid_properties_type = PorousFlowSingleComponentFluid"}>>> = simple_fluid
  stabilization<<<{"description": "Numerical stabilization used.  'Full' means full upwinding.  'KT' means FEM-TVD stabilization of Kuzmin-Turek"}>>> = Full
[]

[FluidProperties<<<{"href": "../../../../syntax/FluidProperties/index.html"}>>>]
  [simple_fluid]
    type = SimpleFluidProperties<<<{"description": "Fluid properties for a simple fluid with a constant bulk density", "href": "../../../../source/fluidproperties/SimpleFluidProperties.html"}>>>
    bulk_modulus<<<{"description": "Constant bulk modulus (Pa)"}>>> = 2e9
    density0<<<{"description": "Density at zero pressure and zero temperature"}>>> = 1000
    thermal_expansion<<<{"description": "Constant coefficient of thermal expansion (1/K)"}>>> = 0
    viscosity<<<{"description": "Constant dynamic viscosity (Pa.s)"}>>> = 1e-3
  []
[]

[Materials<<<{"href": "../../../../syntax/Materials/index.html"}>>>]
  [porosity]
    type = PorousFlowPorosityConst<<<{"description": "This Material calculates the porosity assuming it is constant", "href": "../../../../source/materials/PorousFlowPorosityConst.html"}>>>
    porosity<<<{"description": "The porosity (assumed indepenent of porepressure, temperature, strain, etc, for this material).  This should be a real number, or a constant monomial variable (not a linear lagrange or other kind of variable)."}>>> = 0.1
  []
  [permeability]
    type = PorousFlowPermeabilityConst<<<{"description": "This Material calculates the permeability tensor assuming it is constant", "href": "../../../../source/materials/PorousFlowPermeabilityConst.html"}>>>
    permeability<<<{"description": "The permeability tensor (usually in m^2), which is assumed constant for this material"}>>> = '1E-15 0 0 0 1E-15 0 0 0 1E-15'
  []
[]

[BCs<<<{"href": "../../../../syntax/BCs/index.html"}>>>]
  [left]
    type = DirichletBC<<<{"description": "Imposes the essential boundary condition $u=g$, where $g$ is a constant, controllable value.", "href": "../../../../source/bcs/DirichletBC.html"}>>>
    boundary<<<{"description": "The list of boundary IDs from the mesh where this object applies"}>>> = left
    value<<<{"description": "Value of the BC"}>>> = 3E6
    variable<<<{"description": "The name of the variable that this residual object operates on"}>>> = pp
  []
[]

[Preconditioning<<<{"href": "../../../../syntax/Preconditioning/index.html"}>>>]
  [andy]
    type = SMP<<<{"description": "Single matrix preconditioner (SMP) builds a preconditioner using user defined off-diagonal parts of the Jacobian.", "href": "../../../../source/preconditioners/SingleMatrixPreconditioner.html"}>>>
    full<<<{"description": "Set to true if you want the full set of couplings between variables simply for convenience so you don't have to set every off_diag_row and off_diag_column combination."}>>> = true
  []
[]

[Executioner<<<{"href": "../../../../syntax/Executioner/index.html"}>>>]
  type = Transient
  solve_type = Newton
  dt = 1E3
  end_time = 1E4
[]

[Postprocessors<<<{"href": "../../../../syntax/Postprocessors/index.html"}>>>]
  [p000]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '0 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p010]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '10 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p020]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '20 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p030]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '30 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p040]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '40 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p050]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '50 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p060]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '60 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p070]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '70 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p080]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '80 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p090]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '90 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p100]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = pp
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '100 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [mf_0_010]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = massfrac0
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '10 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'timestep_end'
  []
  [mf_1_010]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = massfrac1
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '10 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'timestep_end'
  []
[]

[Outputs<<<{"href": "../../../../syntax/Outputs/index.html"}>>>]
  file_base<<<{"description": "Common file base name to be utilized with all output objects"}>>> = pressure_pulse_1d_3comp
  print_linear_residuals<<<{"description": "Enable printing of linear residuals to the screen (Console)"}>>> = true
  csv<<<{"description": "Output the scalar variable and postprocessors to a *.csv file using the default CSV output."}>>> = true
[]

Transient 2-phase analysis, with the "water" state fully saturated.

# Pressure pulse in 1D with 2 phases (with one having zero saturation), 2components - transient
[Mesh<<<{"href": "../../../../syntax/Mesh/index.html"}>>>]
  type = GeneratedMesh
  dim = 1
  nx = 10
  xmin = 0
  xmax = 100
[]

[GlobalParams<<<{"href": "../../../../syntax/GlobalParams/index.html"}>>>]
  PorousFlowDictator = dictator
[]

[Variables<<<{"href": "../../../../syntax/Variables/index.html"}>>>]
  [ppwater]
    initial_condition<<<{"description": "Specifies a constant initial condition for this variable"}>>> = 2E6
  []
  [ppgas]
    initial_condition<<<{"description": "Specifies a constant initial condition for this variable"}>>> = 2E6
  []
[]

[AuxVariables<<<{"href": "../../../../syntax/AuxVariables/index.html"}>>>]
  [massfrac_ph0_sp0]
    initial_condition<<<{"description": "Specifies a constant initial condition for this variable"}>>> = 1
  []
  [massfrac_ph1_sp0]
    initial_condition<<<{"description": "Specifies a constant initial condition for this variable"}>>> = 0
  []
[]

[Kernels<<<{"href": "../../../../syntax/Kernels/index.html"}>>>]
  [mass0]
    type = PorousFlowMassTimeDerivative<<<{"description": "Derivative of fluid-component mass with respect to time.  Mass lumping to the nodes is used.", "href": "../../../../source/kernels/PorousFlowMassTimeDerivative.html"}>>>
    fluid_component<<<{"description": "The index corresponding to the component for this kernel"}>>> = 0
    variable<<<{"description": "The name of the variable that this residual object operates on"}>>> = ppwater
  []
  [flux0]
    type = PorousFlowAdvectiveFlux<<<{"description": "Fully-upwinded advective flux of the component given by fluid_component", "href": "../../../../source/kernels/PorousFlowAdvectiveFlux.html"}>>>
    variable<<<{"description": "The name of the variable that this residual object operates on"}>>> = ppwater
    gravity<<<{"description": "Gravitational acceleration vector downwards (m/s^2)"}>>> = '0 0 0'
    fluid_component<<<{"description": "The index corresponding to the fluid component for this kernel"}>>> = 0
  []
  [mass1]
    type = PorousFlowMassTimeDerivative<<<{"description": "Derivative of fluid-component mass with respect to time.  Mass lumping to the nodes is used.", "href": "../../../../source/kernels/PorousFlowMassTimeDerivative.html"}>>>
    fluid_component<<<{"description": "The index corresponding to the component for this kernel"}>>> = 1
    variable<<<{"description": "The name of the variable that this residual object operates on"}>>> = ppgas
  []
  [flux1]
    type = PorousFlowAdvectiveFlux<<<{"description": "Fully-upwinded advective flux of the component given by fluid_component", "href": "../../../../source/kernels/PorousFlowAdvectiveFlux.html"}>>>
    variable<<<{"description": "The name of the variable that this residual object operates on"}>>> = ppgas
    gravity<<<{"description": "Gravitational acceleration vector downwards (m/s^2)"}>>> = '0 0 0'
    fluid_component<<<{"description": "The index corresponding to the fluid component for this kernel"}>>> = 1
  []
[]

[UserObjects<<<{"href": "../../../../syntax/UserObjects/index.html"}>>>]
  [dictator]
    type = PorousFlowDictator<<<{"description": "Holds information on the PorousFlow variable names", "href": "../../../../source/userobjects/PorousFlowDictator.html"}>>>
    porous_flow_vars<<<{"description": "List of primary variables that are used in the PorousFlow simulation.  Jacobian entries involving derivatives wrt these variables will be computed.  In single-phase models you will just have one (eg 'pressure'), in two-phase models you will have two (eg 'p_water p_gas', or 'p_water s_water'), etc."}>>> = 'ppwater ppgas'
    number_fluid_phases<<<{"description": "The number of fluid phases in the simulation"}>>> = 2
    number_fluid_components<<<{"description": "The number of fluid components in the simulation"}>>> = 2
  []
  [pc]
    type = PorousFlowCapillaryPressureVG<<<{"description": "van Genuchten capillary pressure", "href": "../../../../source/userobjects/PorousFlowCapillaryPressureVG.html"}>>>
    m<<<{"description": "van Genuchten exponent m. Must be between 0 and 1, and optimally should be set to >0.5"}>>> = 0.5
    alpha<<<{"description": "van Genuchten parameter alpha. Must be positive"}>>> = 1
  []
[]

[FluidProperties<<<{"href": "../../../../syntax/FluidProperties/index.html"}>>>]
  [simple_fluid0]
    type = SimpleFluidProperties<<<{"description": "Fluid properties for a simple fluid with a constant bulk density", "href": "../../../../source/fluidproperties/SimpleFluidProperties.html"}>>>
    bulk_modulus<<<{"description": "Constant bulk modulus (Pa)"}>>> = 2e9
    density0<<<{"description": "Density at zero pressure and zero temperature"}>>> = 1000
    thermal_expansion<<<{"description": "Constant coefficient of thermal expansion (1/K)"}>>> = 0
    viscosity<<<{"description": "Constant dynamic viscosity (Pa.s)"}>>> = 1e-3
  []
  [simple_fluid1]
    type = SimpleFluidProperties<<<{"description": "Fluid properties for a simple fluid with a constant bulk density", "href": "../../../../source/fluidproperties/SimpleFluidProperties.html"}>>>
    bulk_modulus<<<{"description": "Constant bulk modulus (Pa)"}>>> = 2e6
    density0<<<{"description": "Density at zero pressure and zero temperature"}>>> = 1
    thermal_expansion<<<{"description": "Constant coefficient of thermal expansion (1/K)"}>>> = 0
    viscosity<<<{"description": "Constant dynamic viscosity (Pa.s)"}>>> = 1e-5
  []
[]

[Materials<<<{"href": "../../../../syntax/Materials/index.html"}>>>]
  [temperature]
    type = PorousFlowTemperature<<<{"description": "Material to provide temperature at the quadpoints or nodes and derivatives of it with respect to the PorousFlow variables", "href": "../../../../source/materials/PorousFlowTemperature.html"}>>>
  []
  [ppss]
    type = PorousFlow2PhasePP<<<{"description": "This Material calculates the 2 porepressures and the 2 saturations in a 2-phase situation, and derivatives of these with respect to the PorousFlowVariables", "href": "../../../../source/materials/PorousFlow2PhasePP.html"}>>>
    phase0_porepressure<<<{"description": "Variable that is the porepressure of phase 0 (eg, the water phase).  It will be <= phase1_porepressure."}>>> = ppwater
    phase1_porepressure<<<{"description": "Variable that is the porepressure of phase 1 (eg, the gas phase)"}>>> = ppgas
    capillary_pressure<<<{"description": "Name of the UserObject defining the capillary pressure"}>>> = pc
  []
  [massfrac]
    type = PorousFlowMassFraction<<<{"description": "This Material forms a std::vector<std::vector ...> of mass-fractions out of the individual mass fractions", "href": "../../../../source/materials/PorousFlowMassFraction.html"}>>>
    mass_fraction_vars<<<{"description": "List of variables that represent the mass fractions.  Format is 'f_ph0^c0 f_ph0^c1 f_ph0^c2 ... f_ph0^c(N-2) f_ph1^c0 f_ph1^c1 fph1^c2 ... fph1^c(N-2) ... fphP^c0 f_phP^c1 fphP^c2 ... fphP^c(N-2)' where N=num_components and P=num_phases, and it is assumed that f_ph^c(N-1)=1-sum(f_ph^c,{c,0,N-2}) so that f_ph^c(N-1) need not be given.  If no variables are provided then num_phases=1=num_components."}>>> = 'massfrac_ph0_sp0 massfrac_ph1_sp0'
  []
  [simple_fluid0]
    type = PorousFlowSingleComponentFluid<<<{"description": "This Material calculates fluid properties at the quadpoints or nodes for a single component fluid", "href": "../../../../source/materials/PorousFlowSingleComponentFluid.html"}>>>
    fp<<<{"description": "The name of the user object for fluid properties"}>>> = simple_fluid0
    phase<<<{"description": "The phase number"}>>> = 0
  []
  [simple_fluid1]
    type = PorousFlowSingleComponentFluid<<<{"description": "This Material calculates fluid properties at the quadpoints or nodes for a single component fluid", "href": "../../../../source/materials/PorousFlowSingleComponentFluid.html"}>>>
    fp<<<{"description": "The name of the user object for fluid properties"}>>> = simple_fluid1
    phase<<<{"description": "The phase number"}>>> = 1
  []
  [porosity]
    type = PorousFlowPorosityConst<<<{"description": "This Material calculates the porosity assuming it is constant", "href": "../../../../source/materials/PorousFlowPorosityConst.html"}>>>
    porosity<<<{"description": "The porosity (assumed indepenent of porepressure, temperature, strain, etc, for this material).  This should be a real number, or a constant monomial variable (not a linear lagrange or other kind of variable)."}>>> = 0.1
  []
  [permeability]
    type = PorousFlowPermeabilityConst<<<{"description": "This Material calculates the permeability tensor assuming it is constant", "href": "../../../../source/materials/PorousFlowPermeabilityConst.html"}>>>
    permeability<<<{"description": "The permeability tensor (usually in m^2), which is assumed constant for this material"}>>> = '1E-15 0 0 0 1E-15 0 0 0 1E-15'
  []
  [relperm_water]
    type = PorousFlowRelativePermeabilityCorey<<<{"description": "This Material calculates relative permeability of the fluid phase, using the simple Corey model ((S-S_res)/(1-sum(S_res)))^n", "href": "../../../../source/materials/PorousFlowRelativePermeabilityCorey.html"}>>>
    n<<<{"description": "The Corey exponent of the phase."}>>> = 1
    phase<<<{"description": "The phase number"}>>> = 0
  []
  [relperm_gas]
    type = PorousFlowRelativePermeabilityCorey<<<{"description": "This Material calculates relative permeability of the fluid phase, using the simple Corey model ((S-S_res)/(1-sum(S_res)))^n", "href": "../../../../source/materials/PorousFlowRelativePermeabilityCorey.html"}>>>
    n<<<{"description": "The Corey exponent of the phase."}>>> = 1
    phase<<<{"description": "The phase number"}>>> = 1
  []
[]

[BCs<<<{"href": "../../../../syntax/BCs/index.html"}>>>]
  [leftwater]
    type = DirichletBC<<<{"description": "Imposes the essential boundary condition $u=g$, where $g$ is a constant, controllable value.", "href": "../../../../source/bcs/DirichletBC.html"}>>>
    boundary<<<{"description": "The list of boundary IDs from the mesh where this object applies"}>>> = left
    value<<<{"description": "Value of the BC"}>>> = 3E6
    variable<<<{"description": "The name of the variable that this residual object operates on"}>>> = ppwater
  []
  [leftgas]
    type = DirichletBC<<<{"description": "Imposes the essential boundary condition $u=g$, where $g$ is a constant, controllable value.", "href": "../../../../source/bcs/DirichletBC.html"}>>>
    boundary<<<{"description": "The list of boundary IDs from the mesh where this object applies"}>>> = left
    value<<<{"description": "Value of the BC"}>>> = 3E6
    variable<<<{"description": "The name of the variable that this residual object operates on"}>>> = ppgas
  []
[]

[Preconditioning<<<{"href": "../../../../syntax/Preconditioning/index.html"}>>>]
  [andy]
    type = SMP<<<{"description": "Single matrix preconditioner (SMP) builds a preconditioner using user defined off-diagonal parts of the Jacobian.", "href": "../../../../source/preconditioners/SingleMatrixPreconditioner.html"}>>>
    full<<<{"description": "Set to true if you want the full set of couplings between variables simply for convenience so you don't have to set every off_diag_row and off_diag_column combination."}>>> = true
    petsc_options<<<{"description": "Singleton PETSc options"}>>> = '-snes_converged_reason -ksp_diagonal_scale -ksp_diagonal_scale_fix -ksp_gmres_modifiedgramschmidt -snes_linesearch_monitor'
    petsc_options_iname<<<{"description": "Names of PETSc name/value pairs"}>>> = '-ksp_type -pc_type -sub_pc_type -sub_pc_factor_shift_type -pc_asm_overlap -snes_atol -snes_rtol -snes_max_it'
    petsc_options_value<<<{"description": "Values of PETSc name/value pairs (must correspond with \"petsc_options_iname\""}>>> = 'gmres      asm      lu           NONZERO                   2               1E-15       1E-20 20'
  []
[]

[Executioner<<<{"href": "../../../../syntax/Executioner/index.html"}>>>]
  type = Transient
  solve_type = Newton
  dt = 1E3
  end_time = 1E4
[]

[Postprocessors<<<{"href": "../../../../syntax/Postprocessors/index.html"}>>>]
  [p000]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = ppwater
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '0 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p010]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = ppwater
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '10 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p020]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = ppwater
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '20 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p030]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = ppwater
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '30 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p040]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = ppwater
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '40 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p050]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = ppwater
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '50 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p060]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = ppwater
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '60 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p070]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = ppwater
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '70 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p080]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = ppwater
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '80 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p090]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = ppwater
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '90 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
  [p100]
    type = PointValue<<<{"description": "Compute the value of a variable at a specified location", "href": "../../../../source/postprocessors/PointValue.html"}>>>
    variable<<<{"description": "The name of the variable that this postprocessor operates on."}>>> = ppwater
    point<<<{"description": "The physical point where the solution will be evaluated."}>>> = '100 0 0'
    execute_on<<<{"description": "The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html."}>>> = 'initial timestep_end'
  []
[]

[Outputs<<<{"href": "../../../../syntax/Outputs/index.html"}>>>]
  file_base<<<{"description": "Common file base name to be utilized with all output objects"}>>> = pressure_pulse_1d_2phase
  print_linear_residuals<<<{"description": "Enable printing of linear residuals to the screen (Console)"}>>> = false
  csv<<<{"description": "Output the scalar variable and postprocessors to a *.csv file using the default CSV output."}>>> = true
[]

Transient 2-phase using the "PS" formulation
2-phase using the "PS" formulation and Kuzmin-Turek stabilisation
2 phase using the PS formulation and a van Genuchten capillary pressure
2 phase using the PS formulation and a van Genuchten capillary pressure with a logarithmic extension;
1 phase when the primary variable is $var element = document.getElementById("moose-equation-58ff7c60-500a-494c-ad22-97eb1a8d0f56");katex.render("\\mathrm{log}\\,\\rho", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$
1 phase using the fully-saturated version of PorousFlow (no upwinding and no mass lumping)
1 phase with 3 fluid components using the fully-saturated version of PorousFlow (no upwinding and no mass lumping)

An example verification is shown in Figure 1.

Figure 1: Comparison between the MOOSE result (in dots), and the exact analytic expression given by Eq. (1). The agreement increases for greater spatial resolution and smaller timesteps. Both the multi-component single-phase simulation (using the fully-saturated non-upwinding Kernels, or the partially-saturated full-upwinding Kernels, or the log(mass-density) primary variable) and the 2-phase fully-water-saturated simulation give identical results for the water porepressure.

(modules/porous_flow/test/tests/pressure_pulse/pressure_pulse_1d_steady_action.i)

# Pressure pulse in 1D with 1 phase - steady
# This file employs the PorousFlowFullySaturated Action.  For the non-Action version see pressure_pulse_1d.i
[Mesh]
  type = GeneratedMesh
  dim = 1
  nx = 10
  xmin = 0
  xmax = 100
[]

[GlobalParams]
  PorousFlowDictator = dictator
[]

[Variables]
  [pp]
    initial_condition = 2E6
  []
[]

[PorousFlowFullySaturated]
  porepressure = pp
  gravity = '0 0 0'
  fp = simple_fluid
  stabilization = Full
[]

[FluidProperties]
  [simple_fluid]
    type = SimpleFluidProperties
    bulk_modulus = 2e9
    density0 = 1000
    thermal_expansion = 0
    viscosity = 1e-3
  []
[]

[Materials]
  [permeability]
    type = PorousFlowPermeabilityConst
    permeability = '1E-15 0 0 0 1E-15 0 0 0 1E-15'
  []
[]

[BCs]
  [left]
    type = DirichletBC
    boundary = left
    value = 3E6
    variable = pp
  []
[]

[Preconditioning]
  [andy]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Steady
  solve_type = Newton
[]

[Postprocessors]
  [p000]
    type = PointValue
    variable = pp
    point = '0 0 0'
    execute_on = 'initial timestep_end'
  []
  [p010]
    type = PointValue
    variable = pp
    point = '10 0 0'
    execute_on = 'initial timestep_end'
  []
  [p020]
    type = PointValue
    variable = pp
    point = '20 0 0'
    execute_on = 'initial timestep_end'
  []
  [p030]
    type = PointValue
    variable = pp
    point = '30 0 0'
    execute_on = 'initial timestep_end'
  []
  [p040]
    type = PointValue
    variable = pp
    point = '40 0 0'
    execute_on = 'initial timestep_end'
  []
  [p050]
    type = PointValue
    variable = pp
    point = '50 0 0'
    execute_on = 'initial timestep_end'
  []
  [p060]
    type = PointValue
    variable = pp
    point = '60 0 0'
    execute_on = 'initial timestep_end'
  []
  [p070]
    type = PointValue
    variable = pp
    point = '70 0 0'
    execute_on = 'initial timestep_end'
  []
  [p080]
    type = PointValue
    variable = pp
    point = '80 0 0'
    execute_on = 'initial timestep_end'
  []
  [p090]
    type = PointValue
    variable = pp
    point = '90 0 0'
    execute_on = 'initial timestep_end'
  []
  [p100]
    type = PointValue
    variable = pp
    point = '100 0 0'
    execute_on = 'initial timestep_end'
  []
[]

[Outputs]
  file_base = pressure_pulse_1d_steady
  print_linear_residuals = false
  csv = true
[]

(modules/porous_flow/test/tests/pressure_pulse/pressure_pulse_1d_action.i)

# Pressure pulse in 1D with 1 phase - transient
# This input file uses the PorousFlowFullySaturated Action.  For the non-Action version, see pressure_pulse_1d.i
[Mesh]
  type = GeneratedMesh
  dim = 1
  nx = 10
  xmin = 0
  xmax = 100
[]

[GlobalParams]
  PorousFlowDictator = dictator
[]

[Variables]
  [pp]
    initial_condition = 2E6
  []
[]

[PorousFlowFullySaturated]
  porepressure = pp
  gravity = '0 0 0'
  fp = simple_fluid
  stabilization = Full
[]

[FluidProperties]
  [simple_fluid]
    type = SimpleFluidProperties
    bulk_modulus = 2e9
    density0 = 1000
    thermal_expansion = 0
    viscosity = 1e-3
  []
[]

[Materials]
  [porosity]
    type = PorousFlowPorosityConst
    porosity = 0.1
  []
  [permeability]
    type = PorousFlowPermeabilityConst
    permeability = '1E-15 0 0 0 1E-15 0 0 0 1E-15'
  []
[]

[BCs]
  [left]
    type = DirichletBC
    boundary = left
    value = 3E6
    variable = pp
  []
[]

[Preconditioning]
  [andy]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  solve_type = Newton
  dt = 1E3
  end_time = 1E4
[]

[Postprocessors]
  [p000]
    type = PointValue
    variable = pp
    point = '0 0 0'
    execute_on = 'initial timestep_end'
  []
  [p010]
    type = PointValue
    variable = pp
    point = '10 0 0'
    execute_on = 'initial timestep_end'
  []
  [p020]
    type = PointValue
    variable = pp
    point = '20 0 0'
    execute_on = 'initial timestep_end'
  []
  [p030]
    type = PointValue
    variable = pp
    point = '30 0 0'
    execute_on = 'initial timestep_end'
  []
  [p040]
    type = PointValue
    variable = pp
    point = '40 0 0'
    execute_on = 'initial timestep_end'
  []
  [p050]
    type = PointValue
    variable = pp
    point = '50 0 0'
    execute_on = 'initial timestep_end'
  []
  [p060]
    type = PointValue
    variable = pp
    point = '60 0 0'
    execute_on = 'initial timestep_end'
  []
  [p070]
    type = PointValue
    variable = pp
    point = '70 0 0'
    execute_on = 'initial timestep_end'
  []
  [p080]
    type = PointValue
    variable = pp
    point = '80 0 0'
    execute_on = 'initial timestep_end'
  []
  [p090]
    type = PointValue
    variable = pp
    point = '90 0 0'
    execute_on = 'initial timestep_end'
  []
  [p100]
    type = PointValue
    variable = pp
    point = '100 0 0'
    execute_on = 'initial timestep_end'
  []
[]

[Outputs]
  file_base = pressure_pulse_1d
  print_linear_residuals = false
  csv = true
[]

(modules/porous_flow/test/tests/pressure_pulse/pressure_pulse_1d_3comp_action.i)

# Pressure pulse in 1D with 1 phase but 3 components (viscosity, relperm, etc are independent of mass-fractions) - transient
# This input file uses the PorousFlowFullySaturated Action.  For the non-Action version, see pressure_pulse_1d_3comp.i
[Mesh]
  type = GeneratedMesh
  dim = 1
  nx = 10
  xmin = 0
  xmax = 100
[]

[GlobalParams]
  PorousFlowDictator = dictator
[]

[Variables]
  [pp]
    initial_condition = 2E6
  []
  [massfrac0]
    initial_condition = 0.1
  []
  [massfrac1]
    initial_condition = 0.3
  []
[]

[PorousFlowFullySaturated]
  porepressure = pp
  mass_fraction_vars = 'massfrac0 massfrac1'
  gravity = '0 0 0'
  fp = simple_fluid
  stabilization = Full
[]

[FluidProperties]
  [simple_fluid]
    type = SimpleFluidProperties
    bulk_modulus = 2e9
    density0 = 1000
    thermal_expansion = 0
    viscosity = 1e-3
  []
[]

[Materials]
  [porosity]
    type = PorousFlowPorosityConst
    porosity = 0.1
  []
  [permeability]
    type = PorousFlowPermeabilityConst
    permeability = '1E-15 0 0 0 1E-15 0 0 0 1E-15'
  []
[]

[BCs]
  [left]
    type = DirichletBC
    boundary = left
    value = 3E6
    variable = pp
  []
[]

[Preconditioning]
  [andy]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  solve_type = Newton
  dt = 1E3
  end_time = 1E4
[]

[Postprocessors]
  [p000]
    type = PointValue
    variable = pp
    point = '0 0 0'
    execute_on = 'initial timestep_end'
  []
  [p010]
    type = PointValue
    variable = pp
    point = '10 0 0'
    execute_on = 'initial timestep_end'
  []
  [p020]
    type = PointValue
    variable = pp
    point = '20 0 0'
    execute_on = 'initial timestep_end'
  []
  [p030]
    type = PointValue
    variable = pp
    point = '30 0 0'
    execute_on = 'initial timestep_end'
  []
  [p040]
    type = PointValue
    variable = pp
    point = '40 0 0'
    execute_on = 'initial timestep_end'
  []
  [p050]
    type = PointValue
    variable = pp
    point = '50 0 0'
    execute_on = 'initial timestep_end'
  []
  [p060]
    type = PointValue
    variable = pp
    point = '60 0 0'
    execute_on = 'initial timestep_end'
  []
  [p070]
    type = PointValue
    variable = pp
    point = '70 0 0'
    execute_on = 'initial timestep_end'
  []
  [p080]
    type = PointValue
    variable = pp
    point = '80 0 0'
    execute_on = 'initial timestep_end'
  []
  [p090]
    type = PointValue
    variable = pp
    point = '90 0 0'
    execute_on = 'initial timestep_end'
  []
  [p100]
    type = PointValue
    variable = pp
    point = '100 0 0'
    execute_on = 'initial timestep_end'
  []
  [mf_0_010]
    type = PointValue
    variable = massfrac0
    point = '10 0 0'
    execute_on = 'timestep_end'
  []
  [mf_1_010]
    type = PointValue
    variable = massfrac1
    point = '10 0 0'
    execute_on = 'timestep_end'
  []
[]

[Outputs]
  file_base = pressure_pulse_1d_3comp
  print_linear_residuals = true
  csv = true
[]

(modules/porous_flow/test/tests/pressure_pulse/pressure_pulse_1d_2phase.i)

# Pressure pulse in 1D with 2 phases (with one having zero saturation), 2components - transient
[Mesh]
  type = GeneratedMesh
  dim = 1
  nx = 10
  xmin = 0
  xmax = 100
[]

[GlobalParams]
  PorousFlowDictator = dictator
[]

[Variables]
  [ppwater]
    initial_condition = 2E6
  []
  [ppgas]
    initial_condition = 2E6
  []
[]

[AuxVariables]
  [massfrac_ph0_sp0]
    initial_condition = 1
  []
  [massfrac_ph1_sp0]
    initial_condition = 0
  []
[]

[Kernels]
  [mass0]
    type = PorousFlowMassTimeDerivative
    fluid_component = 0
    variable = ppwater
  []
  [flux0]
    type = PorousFlowAdvectiveFlux
    variable = ppwater
    gravity = '0 0 0'
    fluid_component = 0
  []
  [mass1]
    type = PorousFlowMassTimeDerivative
    fluid_component = 1
    variable = ppgas
  []
  [flux1]
    type = PorousFlowAdvectiveFlux
    variable = ppgas
    gravity = '0 0 0'
    fluid_component = 1
  []
[]

[UserObjects]
  [dictator]
    type = PorousFlowDictator
    porous_flow_vars = 'ppwater ppgas'
    number_fluid_phases = 2
    number_fluid_components = 2
  []
  [pc]
    type = PorousFlowCapillaryPressureVG
    m = 0.5
    alpha = 1
  []
[]

[FluidProperties]
  [simple_fluid0]
    type = SimpleFluidProperties
    bulk_modulus = 2e9
    density0 = 1000
    thermal_expansion = 0
    viscosity = 1e-3
  []
  [simple_fluid1]
    type = SimpleFluidProperties
    bulk_modulus = 2e6
    density0 = 1
    thermal_expansion = 0
    viscosity = 1e-5
  []
[]

[Materials]
  [temperature]
    type = PorousFlowTemperature
  []
  [ppss]
    type = PorousFlow2PhasePP
    phase0_porepressure = ppwater
    phase1_porepressure = ppgas
    capillary_pressure = pc
  []
  [massfrac]
    type = PorousFlowMassFraction
    mass_fraction_vars = 'massfrac_ph0_sp0 massfrac_ph1_sp0'
  []
  [simple_fluid0]
    type = PorousFlowSingleComponentFluid
    fp = simple_fluid0
    phase = 0
  []
  [simple_fluid1]
    type = PorousFlowSingleComponentFluid
    fp = simple_fluid1
    phase = 1
  []
  [porosity]
    type = PorousFlowPorosityConst
    porosity = 0.1
  []
  [permeability]
    type = PorousFlowPermeabilityConst
    permeability = '1E-15 0 0 0 1E-15 0 0 0 1E-15'
  []
  [relperm_water]
    type = PorousFlowRelativePermeabilityCorey
    n = 1
    phase = 0
  []
  [relperm_gas]
    type = PorousFlowRelativePermeabilityCorey
    n = 1
    phase = 1
  []
[]

[BCs]
  [leftwater]
    type = DirichletBC
    boundary = left
    value = 3E6
    variable = ppwater
  []
  [leftgas]
    type = DirichletBC
    boundary = left
    value = 3E6
    variable = ppgas
  []
[]

[Preconditioning]
  [andy]
    type = SMP
    full = true
    petsc_options = '-snes_converged_reason -ksp_diagonal_scale -ksp_diagonal_scale_fix -ksp_gmres_modifiedgramschmidt -snes_linesearch_monitor'
    petsc_options_iname = '-ksp_type -pc_type -sub_pc_type -sub_pc_factor_shift_type -pc_asm_overlap -snes_atol -snes_rtol -snes_max_it'
    petsc_options_value = 'gmres      asm      lu           NONZERO                   2               1E-15       1E-20 20'
  []
[]

[Executioner]
  type = Transient
  solve_type = Newton
  dt = 1E3
  end_time = 1E4
[]

[Postprocessors]
  [p000]
    type = PointValue
    variable = ppwater
    point = '0 0 0'
    execute_on = 'initial timestep_end'
  []
  [p010]
    type = PointValue
    variable = ppwater
    point = '10 0 0'
    execute_on = 'initial timestep_end'
  []
  [p020]
    type = PointValue
    variable = ppwater
    point = '20 0 0'
    execute_on = 'initial timestep_end'
  []
  [p030]
    type = PointValue
    variable = ppwater
    point = '30 0 0'
    execute_on = 'initial timestep_end'
  []
  [p040]
    type = PointValue
    variable = ppwater
    point = '40 0 0'
    execute_on = 'initial timestep_end'
  []
  [p050]
    type = PointValue
    variable = ppwater
    point = '50 0 0'
    execute_on = 'initial timestep_end'
  []
  [p060]
    type = PointValue
    variable = ppwater
    point = '60 0 0'
    execute_on = 'initial timestep_end'
  []
  [p070]
    type = PointValue
    variable = ppwater
    point = '70 0 0'
    execute_on = 'initial timestep_end'
  []
  [p080]
    type = PointValue
    variable = ppwater
    point = '80 0 0'
    execute_on = 'initial timestep_end'
  []
  [p090]
    type = PointValue
    variable = ppwater
    point = '90 0 0'
    execute_on = 'initial timestep_end'
  []
  [p100]
    type = PointValue
    variable = ppwater
    point = '100 0 0'
    execute_on = 'initial timestep_end'
  []
[]

[Outputs]
  file_base = pressure_pulse_1d_2phase
  print_linear_residuals = false
  csv = true
[]