# 1D Transient Flow (Pressure), BCs of 1st Kind¶

The Problem Description

The PFLOTRAN Input File (GENERAL Mode)

The PFLOTRAN Input File (TH Mode)

The PFLOTRAN Input File (RICHARDS Mode)

The Python Script

## The Problem Description¶

This problem is adapted from Kolditz, et al. (2015), Thermo-Hydro-Mechanical-Chemical Processes in Fractured Porous Media: Modelling and Benchmarking, Closed Form Solutions, Springer International Publishing, Switzerland. Section 2.2.7, pg.32, “A Transient 1D Pressure Distribution, Time-Dependent Boundary Conditions of 1st Kind.”

The domain is a 20x1x1 meter rectangular column extending along the positive and negative x-axis and is made up of 20x1x1 cubic grid cells with dimensions 1x1x1 meters. The domain material is assigned a porosity :math”phi = 0.25, and permeability $$k$$ = 1e-14 m2. The fluid has a viscosity $$\mu$$ = 1.728 mPa-sec, and a constant compressibility $$K$$ = 1e-8 1/Pa.

The pressure is initially uniform at p(t=0) = 0.25 MPa. The boundary pressures are transient:

\begin{align}\begin{aligned}p(-L,t) = p_b t + p_{t=0}\\p(L,t) = p_b t + p_{t=0}\end{aligned}\end{align}

where L = 10 m and $$p_b$$ = 2 MPa/day. The transient pressure distribution is governed by,

$\phi K {{\partial p} \over {\partial t}} = {k \over \mu} {{\partial^{2} p} \over {\partial x^{2}}}$

With the given boundary conditions, the solution is defined by,

\begin{align}\begin{aligned}\chi = {k \over {\phi \mu K}}\\p(x,t) = p_b t + {{p_b(x^2-L^2)}\over{2\chi}} + {{16 p_b L^2}\over{\chi\pi^3}} \sum_{n=0}^{\infty}{{(-1)^n}\over{(2n+1)^3}} cos{\left({{(2n+1)x\pi}\over{2L}}\right)} e^{\left({-\chi(2n+1)^2\pi^2{{t}\over{4L^2}}}\right)}\end{aligned}\end{align}

## The PFLOTRAN Input File (GENERAL Mode)¶

The GENERAL Mode PFLOTRAN input file can be downloaded here.


SIMULATION
SIMULATION_TYPE SUBSURFACE
PROCESS_MODELS
SUBSURFACE_FLOW flow
MODE GENERAL
/
/
END

SUBSURFACE

GRID
TYPE structured
NXYZ 10 1 1
DXYZ
2.0d0
1.0d0
1.0d0
END
END

REGION all
COORDINATES
0.0d0 0.0d0 0.0d0
20.0d0 1.0d0 1.0d0
/
END

REGION left_end
FACE WEST
COORDINATES
0.d0 0.d0 0.d0
0.d0 1.0d0 1.0d0
/
END

REGION right_end
FACE EAST
COORDINATES
20.0d0 0.d0 0.d0
20.0d0 1.0d0 1.0d0
/
END

MATERIAL_PROPERTY beam
ID 1
POROSITY 0.25
TORTUOSITY 1.d0
ROCK_DENSITY 2.5d3 kg/m^3
HEAT_CAPACITY 1.5 J/kg-C
THERMAL_CONDUCTIVITY_DRY 2.0 W/m-C
THERMAL_CONDUCTIVITY_WET 2.0 W/m-C
CHARACTERISTIC_CURVES cc1
PERMEABILITY
PERM_X 1.d-14
PERM_Y 1.d-14
PERM_Z 1.d-14
/
END

CHARACTERISTIC_CURVES cc1
SATURATION_FUNCTION VAN_GENUCHTEN
LIQUID_RESIDUAL_SATURATION 0.5d-1
M 0.75
ALPHA 1.d-3
/
PERMEABILITY_FUNCTION MUALEM
LIQUID_RESIDUAL_SATURATION 0.1d0
M 0.5d0
/
PERMEABILITY_FUNCTION MUALEM_VG_GAS
LIQUID_RESIDUAL_SATURATION 0.1d0
GAS_RESIDUAL_SATURATION 0.1d0
M 0.5d0
/
END

EOS WATER
#ref. density [kg/m3], ref. pressure [Pa], water compressibility [1/Pa?]
DENSITY EXPONENTIAL 1000. 0. 1.d-8
VISCOSITY CONSTANT 1.728d-3 Pa-s
END

FLUID_PROPERTY
DIFFUSION_COEFFICIENT 1.d-9
END

STRATA
REGION all
MATERIAL beam
END

TIME
FINAL_TIME 0.75 day
INITIAL_TIMESTEP_SIZE 1.d-4 day
MAXIMUM_TIMESTEP_SIZE 0.0001 day at 0.d0 day
END

OUTPUT
SNAPSHOT_FILE
TIMES day 0.10 0.25 0.50
#NO_PRINT_INITIAL
FORMAT HDF5
/
END

FLOW_CONDITION initial
TYPE
TEMPERATURE dirichlet
LIQUID_PRESSURE dirichlet
MOLE_FRACTION dirichlet
/
TEMPERATURE 25.0d0 C
LIQUID_PRESSURE 0.25 MPa
MOLE_FRACTION 1.d-10
END

FLOW_CONDITION left_end
TYPE
TEMPERATURE dirichlet
LIQUID_PRESSURE dirichlet
MOLE_FRACTION dirichlet
/
TEMPERATURE 25.0 C
LIQUID_PRESSURE LIST
# p = p_b*t + offset; p_b=2e6 Pa/day; offset = 0.25 MPa
TIME_UNITS day
DATA_UNITS Pa
INTERPOLATION LINEAR
#time  #pressure
0.00d0 0.25d6
0.25d0 0.75d6
0.50d0 1.25d6
1.00d0 2.25d6
/
MOLE_FRACTION 1.d-10
END

FLOW_CONDITION right_end
TYPE
TEMPERATURE dirichlet
LIQUID_PRESSURE dirichlet
MOLE_FRACTION dirichlet
/
TEMPERATURE 25.0 C
LIQUID_PRESSURE LIST
# p = p_b*t + offset; p_b=2e6 Pa/day; offset = 0.25 MPa
TIME_UNITS day
DATA_UNITS Pa
INTERPOLATION LINEAR
#time  #pressure
0.00d0 0.25d6
0.25d0 0.75d6
0.50d0 1.25d6
1.00d0 2.25d6
/
MOLE_FRACTION 1.d-10
END

INITIAL_CONDITION initial
REGION all
FLOW_CONDITION initial
END

BOUNDARY_CONDITION left_end
REGION left_end
FLOW_CONDITION left_end
END

BOUNDARY_CONDITION right_end
FLOW_CONDITION right_end
REGION right_end
END

END_SUBSURFACE


## The PFLOTRAN Input File (TH Mode)¶

The TH Mode PFLOTRAN input file can be downloaded here.


SIMULATION
SIMULATION_TYPE SUBSURFACE
PROCESS_MODELS
SUBSURFACE_FLOW flow
MODE TH
/
/
END

SUBSURFACE

GRID
TYPE structured
NXYZ 10 1 1
DXYZ
2.0d0
1.0d0
1.0d0
END
END

REGION all
COORDINATES
0.0d0 0.0d0 0.0d0
20.0d0 1.0d0 1.0d0
/
END

REGION left_end
FACE WEST
COORDINATES
0.d0 0.d0 0.d0
0.d0 1.0d0 1.0d0
/
END

REGION right_end
FACE EAST
COORDINATES
20.0d0 0.d0 0.d0
20.0d0 1.0d0 1.0d0
/
END

MATERIAL_PROPERTY beam
ID 1
POROSITY 0.25
TORTUOSITY 1.d0
ROCK_DENSITY 2.5d3 kg/m^3
SPECIFIC_HEAT 1.5 J/kg-C
THERMAL_CONDUCTIVITY_DRY 2.0 W/m-C
THERMAL_CONDUCTIVITY_WET 2.0 W/m-C
SATURATION_FUNCTION default
PERMEABILITY
PERM_X 1.d-14
PERM_Y 1.d-14
PERM_Z 1.d-14
/
END

SATURATION_FUNCTION default
SATURATION_FUNCTION_TYPE VAN_GENUCHTEN
RESIDUAL_SATURATION 0.5d-1
LAMBDA 0.75
ALPHA 1.d-3
END

EOS WATER
#ref. density [kg/m3], ref. pressure [Pa], water compressibility [1/Pa?]
DENSITY EXPONENTIAL 1000. 0. 1.d-8
VISCOSITY CONSTANT 1.728d-3 Pa-s
END

FLUID_PROPERTY
DIFFUSION_COEFFICIENT 1.d-9
END

STRATA
REGION all
MATERIAL beam
END

TIME
FINAL_TIME 0.75 day
INITIAL_TIMESTEP_SIZE 1.d-4 day
MAXIMUM_TIMESTEP_SIZE 0.0001 day at 0.d0 day
END

OUTPUT
SNAPSHOT_FILE
TIMES day 0.10 0.25 0.50
#NO_PRINT_INITIAL
FORMAT HDF5
/
END

FLOW_CONDITION initial
TYPE
TEMPERATURE dirichlet
PRESSURE dirichlet
/
TEMPERATURE 25.0d0 C
PRESSURE 0.25 MPa
END

FLOW_CONDITION left_end
TYPE
TEMPERATURE dirichlet
PRESSURE dirichlet
/
TEMPERATURE 25.0 C
PRESSURE LIST
# p = p_b*t + offset; p_b=2e6 Pa/day; offset = 0.25 MPa
TIME_UNITS day
DATA_UNITS Pa
INTERPOLATION LINEAR
#time  #pressure
0.00d0 0.25d6
0.25d0 0.75d6
0.50d0 1.25d6
1.00d0 2.25d6
/
END

FLOW_CONDITION right_end
TYPE
TEMPERATURE dirichlet
PRESSURE dirichlet
/
TEMPERATURE 25.0 C
PRESSURE LIST
# p = p_b*t + offset; p_b=2e6 Pa/day; offset = 0.25 MPa
TIME_UNITS day
DATA_UNITS Pa
INTERPOLATION LINEAR
#time  #pressure
0.00d0 0.25d6
0.25d0 0.75d6
0.50d0 1.25d6
1.00d0 2.25d6
/
END

INITIAL_CONDITION initial
REGION all
FLOW_CONDITION initial
END

BOUNDARY_CONDITION left_end
REGION left_end
FLOW_CONDITION left_end
END

BOUNDARY_CONDITION right_end
FLOW_CONDITION right_end
REGION right_end
END

END_SUBSURFACE


## The PFLOTRAN Input File (RICHARDS Mode)¶

The RICHARDS Mode PFLOTRAN input file can be downloaded here.


SIMULATION
SIMULATION_TYPE SUBSURFACE
PROCESS_MODELS
SUBSURFACE_FLOW flow
MODE RICHARDS
/
/
END

SUBSURFACE

GRID
TYPE structured
NXYZ 10 1 1
DXYZ
2.0d0
1.0d0
1.0d0
END
END

REGION all
COORDINATES
0.0d0 0.0d0 0.0d0
20.0d0 1.0d0 1.0d0
/
END

REGION left_end
FACE WEST
COORDINATES
0.d0 0.d0 0.d0
0.d0 1.0d0 1.0d0
/
END

REGION right_end
FACE EAST
COORDINATES
20.0d0 0.d0 0.d0
20.0d0 1.0d0 1.0d0
/
END

MATERIAL_PROPERTY beam
ID 1
POROSITY 0.25
TORTUOSITY 1.d0
ROCK_DENSITY 2.5d3 kg/m^3
CHARACTERISTIC_CURVES cc1
PERMEABILITY
PERM_X 1.d-14
PERM_Y 1.d-14
PERM_Z 1.d-14
/
END

CHARACTERISTIC_CURVES cc1
SATURATION_FUNCTION VAN_GENUCHTEN
LIQUID_RESIDUAL_SATURATION 0.5d-1
M 0.75
ALPHA 1.d-3
/
PERMEABILITY_FUNCTION MUALEM
LIQUID_RESIDUAL_SATURATION 0.1d0
M 0.5d0
/
PERMEABILITY_FUNCTION MUALEM_VG_GAS
LIQUID_RESIDUAL_SATURATION 0.1d0
GAS_RESIDUAL_SATURATION 0.1d0
M 0.5d0
/
END

EOS WATER
#ref. density [kg/m3], ref. pressure [Pa], water compressibility [1/Pa?]
DENSITY EXPONENTIAL 1000. 0. 1.d-8
VISCOSITY CONSTANT 1.728d-3 Pa-s
END

FLUID_PROPERTY
DIFFUSION_COEFFICIENT 1.d-9
END

STRATA
REGION all
MATERIAL beam
END

TIME
FINAL_TIME 0.75 day
INITIAL_TIMESTEP_SIZE 1.d-4 day
MAXIMUM_TIMESTEP_SIZE 0.0001 day at 0.d0 day
END

OUTPUT
SNAPSHOT_FILE
TIMES day 0.10 0.25 0.50
#NO_PRINT_INITIAL
FORMAT HDF5
/
END

FLOW_CONDITION initial
TYPE
PRESSURE dirichlet
/
PRESSURE 0.25 MPa
END

FLOW_CONDITION left_end
TYPE
PRESSURE dirichlet
/
PRESSURE LIST
# p = p_b*t + offset; p_b=2e6 Pa/day; offset = 0.25 MPa
TIME_UNITS day
DATA_UNITS Pa
INTERPOLATION LINEAR
#time  #pressure
0.00d0 0.25d6
0.25d0 0.75d6
0.50d0 1.25d6
1.00d0 2.25d6
/
END

FLOW_CONDITION right_end
TYPE
PRESSURE dirichlet
/
PRESSURE LIST
# p = p_b*t + offset; p_b=2e6 Pa/day; offset = 0.25 MPa
TIME_UNITS day
DATA_UNITS Pa
INTERPOLATION LINEAR
#time  #pressure
0.00d0 0.25d6
0.25d0 0.75d6
0.50d0 1.25d6
1.00d0 2.25d6
/
END

INITIAL_CONDITION initial
REGION all
FLOW_CONDITION initial
END

BOUNDARY_CONDITION left_end
REGION left_end
FLOW_CONDITION left_end
END

BOUNDARY_CONDITION right_end
FLOW_CONDITION right_end
REGION right_end
END

END_SUBSURFACE


## The Python Script¶

def flow_transient_1D_BC1stkind(path,input_prefix,remove,screen_on,pf_exe,
mpi_exe,num_tries):
#==============================================================================#
# Based on:
# Kolditz, et al. (2015) Thermo-Hydro-Mechanical-Chemical Processes in
# Fractured Porous Media: Modelling and Benchmarking, Closed Form Solutions,
# Springer International Publishing, Switzerland.
# Section 2.2.7, pg.32
# "A Transient 1D Pressure Distribution, Time-Dependent Boundary Conditions
# of 1st Kind"
# With some modification of the parameter values given in Kolditz (2015)
#
# Author: Jenn Frederick
# Date: 08/23/2016
# ******************************************************************************
nxyz = np.zeros(3) + 1
dxyz = np.zeros(3) + 1.
lxyz = np.zeros(3) + 1.
error_analysis = np.zeros(num_tries)
dxyz_record = np.zeros((num_tries,3))
test_pass = False
try_count = 0

# initial discretization values
lxyz[0] = 20.                # [m] lx
nxyz[0] = 10                 # [m] nx
dxyz = lxyz/nxyz             # [m]
k = 1.0e-14                  # [m^2]
mu = 1.728e-3                # [Pa*sec]
por = 0.25                   # [-]
K = 1.0e-8                   # [1/Pa]
pb_day = 2.0e6               # [Pa/day]
pb_sec = 2.0e6/(24.0*3600.0) # [Pa/sec]
p_offset = 0.25e6            # [Pa]
chi = k/(por*K*mu)
ierr = 0

while (not test_pass) and (try_count < num_tries):
print_discretization(lxyz,nxyz,dxyz)
nx = int(nxyz[0]); ny = int(nxyz[1]); nz = int(nxyz[2])
dx = dxyz[0]; dy = dxyz[1]; dz = dxyz[2]
Lx = lxyz[0]; Ly = lxyz[1]; Lz = lxyz[2]
try_count = try_count + 1

x_soln1 = np.linspace(0.+(dx/2.),(Lx/2.)-(dx/2.),nx/2.)        # [m]
x_soln2 = np.linspace(-((Lx/2.)-(dx/2.)),-(0.+(dx/2.)),nx/2.)  # [m]
x_soln = np.concatenate((x_soln2,x_soln1),axis=0)              # [m]
# Add boundary values to analytical solution
x_soln = np.concatenate(([-(Lx/2.)],x_soln),axis=0)            # [m]
x_soln = np.concatenate((x_soln,[Lx/2.]),axis=0)               # [m]
t_soln = np.array([0.10,0.25,0.50,0.75])                       # [day]
p_soln = np.zeros((4,(nx+2)))                                  # [Pa]
x_pflotran1 = np.linspace(0.+(dx/2.),(Lx/2.)-(dx/2.),nx/2.)    # [m]
x_pflotran2 = np.linspace(-((Lx/2.)-(dx/2.)),-(0.+(dx/2.)),nx/2.)  # [m]
x_pflotran = np.concatenate((x_pflotran2,x_pflotran1),axis=0)  # [m]
p_pflotran = np.zeros((4,nx))                                  # [Pa]

# create the analytical solution
for time in range(4):
t = t_soln[time]*(24.0*3600.0)   # [sec]
p_soln[time,:] = pb_sec*t + ((pb_sec*(pow(x_soln,2)-pow((Lx/2.),2)))/(2.*chi))
sum_term = np.zeros(nx+2)
sum_term_old = np.zeros(nx+2)
n = 0
epsilon = 1.0
while epsilon > epsilon_value:
sum_term_old = sum_term
sum_term = sum_term_old + (((pow(-1.,n))/(pow(((2*n)+1),3)))*np.cos((math.pi*x_soln*((2*n)+1))/(2*(Lx/2.)))*np.exp(-chi*pow((2*n)+1,2)*pow(math.pi,2)*(t/(4*pow((Lx/2.),2)))))
epsilon = np.max(np.abs(sum_term_old-sum_term))
n = n + 1
p_soln[time,:] = p_offset + p_soln[time,:] + ((16.*pb_sec*pow((Lx/2.),2))/(chi*pow(math.pi,3)))*sum_term

# run PFLOTRAN simulation
run_pflotran(input_prefix,nxyz,dxyz,lxyz,remove,screen_on,pf_exe,mpi_exe)

# load data from HDF5
index_string = 'Time:  1.00000E-01 d/Liquid_Pressure [Pa]'
'/1D_transient_pressure_BC_1st_kind.h5',index_string,False)
index_string = 'Time:  2.50000E-01 d/Liquid_Pressure [Pa]'
'/1D_transient_pressure_BC_1st_kind.h5',index_string,False)
index_string = 'Time:  5.00000E-01 d/Liquid_Pressure [Pa]'
'/1D_transient_pressure_BC_1st_kind.h5',index_string,False)
index_string = 'Time:  7.50000E-01 d/Liquid_Pressure [Pa]'
'/1D_transient_pressure_BC_1st_kind.h5',index_string,remove)
ierr = check(p_pflotran)

# Convert units [Pa -> MPa]
p_pflotran = p_pflotran/1.e6
p_soln = p_soln/1.e6

max_percent_error = calc_relative_error(p_soln[:,1:nx+1],p_pflotran,ierr)
record_error(error_analysis,dxyz_record,max_percent_error,dxyz,try_count)
test_pass = does_pass(max_percent_error,try_count,num_tries)
nxyz[0] = nxyz[0]*2.
dxyz = lxyz/nxyz

# Plot the PFLOTRAN and analytical solutions
plot_1D_transient(path,t_soln,'day',x_soln,p_soln,x_pflotran,p_pflotran,
'Distance [m]','Pressure [MPa]',"{0:.2f}".format(max_percent_error))

# Plot error analysis
plot_error(error_analysis,dxyz_record,path,try_count)

# Add test result to report card

return;


Refer to section Python Helper Functions for documentation on the qa_tests_helper module, which defines the helper functions used in the Python script above.

# 1D Transient Flow (Pressure), BCs of 2nd Kind¶

The Problem Description

The PFLOTRAN Input File (GENERAL Mode)

The PFLOTRAN Input File (TH Mode)

The PFLOTRAN Input File (RICHARDS Mode)

The Python Script

## The Problem Description¶

This problem is adapted from Kolditz, et al. (2015), Thermo-Hydro-Mechanical-Chemical Processes in Fractured Porous Media: Modelling and Benchmarking, Closed Form Solutions, Springer International Publishing, Switzerland. Section 2.2.8, pg.33, “A Transient 1D Pressure Distribution, Time-Dependent Boundary Conditions of 2nd Kind.”

The domain is a 25x1x1 meter rectangular column extending along the positive x-axis and is made up of 50x1x1 cubic grid cells with dimensions 0.5x1x1 meters. The domain material is assigned the following properties: porosity $$\phi$$ = 0.25; $$k$$ = 1.0e-14 m^2. The fluid viscosity $$\mu$$ = 0.864 mPa/sec, and the fluid compressibility $$K$$ = 1.0e-8 1/Pa. The accuracy of the numerical solution is very sensitive to the time step size because the fluid flux value is held constant at the value at the beginning of the timestep. Reducing the timestep will make the numerical solution more accurate relative to the analytical solution, but note this is not an issue with time truncation error.

The pressure is initially uniform at p(t=0) = 0 MPa. At the left end, a no fluid flux boundary condition is applied, and at the right end, a transient fluid flux boundary condition is applied (both in units of m/sec):

\begin{align}\begin{aligned}q(0,t) = 0\\q(L,t) = 9.0x10^{-6} t\end{aligned}\end{align}

where L = 25 m. The transient pressure distribution is governed by,

\begin{align}\begin{aligned}\chi = {k \over {\phi \mu K}}\\{\phi K} {{\partial p} \over {\partial t}} = {k \over \mu} {{\partial^{2} p} \over {\partial x^{2}}}\end{aligned}\end{align}

With the given boundary conditions, the solution is defined by,

$p(x,t) = {{8q\sqrt{\chi t^3}} \over {k \over \mu}} \sum_{n=0}^{\infty} \left[{ i^3erfc{{(2n+1)L-x}\over{2\sqrt{\chi t}}} + i^3erfc{{(2n+1)L+x}\over{2\sqrt{\chi t}}} }\right]$

where $$i^3erfc(g)$$ represents the third repeated integral of the complimentary error function, given by,

$i^3erfc(g) = {2 \over \pi} \int^{\infty}_{g} {{(s-g)^3}\over{3!}} e^{-s^2} ds$

## The PFLOTRAN Input File (GENERAL Mode)¶

The General Mode PFLOTRAN input file can be downloaded here.


SIMULATION
SIMULATION_TYPE SUBSURFACE
PROCESS_MODELS
SUBSURFACE_FLOW flow
MODE GENERAL
/
/
END

SUBSURFACE

GRID
TYPE structured
NXYZ 10 1 1
DXYZ
2.5d0
1.0d0
1.0d0
END
END

REGION all
COORDINATES
0.0d0 0.0d0 0.0d0
25.0d0 1.0d0 1.0d0
/
END

REGION left_end
FACE WEST
COORDINATES
0.d0 0.d0 0.d0
0.d0 1.0d0 1.0d0
/
END

REGION right_end
FACE EAST
COORDINATES
25.0d0 0.d0 0.d0
25.0d0 1.0d0 1.0d0
/
END

MATERIAL_PROPERTY beam
ID 1
POROSITY 0.20
TORTUOSITY 1.d0
ROCK_DENSITY 2.0d3 kg/m^3
HEAT_CAPACITY 100. J/kg-C
THERMAL_CONDUCTIVITY_DRY 1.16 W/m-C
THERMAL_CONDUCTIVITY_WET 1.16 W/m-C
CHARACTERISTIC_CURVES cc1
PERMEABILITY
PERM_X 1.d-14
PERM_Y 1.d-14
PERM_Z 1.d-14
/
END

CHARACTERISTIC_CURVES cc1
SATURATION_FUNCTION VAN_GENUCHTEN
LIQUID_RESIDUAL_SATURATION 0.5d-1
M 0.75
ALPHA 1.d-3
/
PERMEABILITY_FUNCTION MUALEM
LIQUID_RESIDUAL_SATURATION 0.1d0
M 0.5d0
/
PERMEABILITY_FUNCTION MUALEM_VG_GAS
LIQUID_RESIDUAL_SATURATION 0.1d0
GAS_RESIDUAL_SATURATION 0.1d0
M 0.5d0
/
END

EOS WATER
# ref. density, ref. pressure, water compressibility
DENSITY EXPONENTIAL 1000. 101325. 1.d-8
VISCOSITY CONSTANT 0.864d-3 Pa-s
END

FLUID_PROPERTY
DIFFUSION_COEFFICIENT 1.d-9
END

LINEAR_SOLVER FLOW
SOLVER DIRECT
ZERO_PIVOT_TOL 1.d-20
END

STRATA
REGION all
MATERIAL beam
END

TIME
FINAL_TIME 0.20 day
INITIAL_TIMESTEP_SIZE 1.d-4 day
MAXIMUM_TIMESTEP_SIZE 0.0001 day at 0.d0 day
END

OUTPUT
SNAPSHOT_FILE
TIMES day 0.01 0.04 0.09 0.12
NO_PRINT_INITIAL
FORMAT HDF5
/
END

FLOW_CONDITION initial
TYPE
TEMPERATURE dirichlet
LIQUID_PRESSURE dirichlet
MOLE_FRACTION dirichlet
/
TEMPERATURE 25.0d0 C
LIQUID_PRESSURE 101325 Pa
MOLE_FRACTION 1.d-10
END

FLOW_CONDITION left_end
TYPE
LIQUID_FLUX neumann
TEMPERATURE dirichlet
GAS_FLUX neumann
/
LIQUID_FLUX 0.d0 m/sec
TEMPERATURE 25.0d0 C
GAS_FLUX 0.d0 m/sec
END

FLOW_CONDITION right_end
TYPE
LIQUID_FLUX neumann
TEMPERATURE dirichlet
GAS_FLUX neumann
/
LIQUID_FLUX LIST
# liquid_flux = (9.0d-6)*t [m/sec]
TIME_UNITS day
DATA_UNITS m/sec
INTERPOLATION LINEAR
#time  #liquid_flux
0.00d0 0.0d0
1.00d0 9.0d-6
/
TEMPERATURE 25.0d0 C
GAS_FLUX 0.d0 m/sec
END

INITIAL_CONDITION initial
REGION all
FLOW_CONDITION initial
END

BOUNDARY_CONDITION left_end
REGION left_end
FLOW_CONDITION left_end
END

BOUNDARY_CONDITION right_end
FLOW_CONDITION right_end
REGION right_end
END

END_SUBSURFACE


## The PFLOTRAN Input File (TH Mode)¶

The TH Mode PFLOTRAN input file can be downloaded here.


SIMULATION
SIMULATION_TYPE SUBSURFACE
PROCESS_MODELS
SUBSURFACE_FLOW flow
MODE TH
/
/
END

SUBSURFACE

GRID
TYPE structured
NXYZ 10 1 1
DXYZ
2.5d0
1.0d0
1.0d0
END
END

REGION all
COORDINATES
0.0d0 0.0d0 0.0d0
25.0d0 1.0d0 1.0d0
/
END

REGION left_end
FACE WEST
COORDINATES
0.d0 0.d0 0.d0
0.d0 1.0d0 1.0d0
/
END

REGION right_end
FACE EAST
COORDINATES
25.0d0 0.d0 0.d0
25.0d0 1.0d0 1.0d0
/
END

MATERIAL_PROPERTY beam
ID 1
POROSITY 0.20
TORTUOSITY 1.d0
ROCK_DENSITY 2.0d3 kg/m^3
SPECIFIC_HEAT 100.0 J/kg-C
THERMAL_CONDUCTIVITY_DRY 1.16 W/m-C
THERMAL_CONDUCTIVITY_WET 1.16 W/m-C
SATURATION_FUNCTION default
PERMEABILITY
PERM_X 1.d-14
PERM_Y 1.d-14
PERM_Z 1.d-14
/
END

SATURATION_FUNCTION default
SATURATION_FUNCTION_TYPE VAN_GENUCHTEN
RESIDUAL_SATURATION 0.5d-1
LAMBDA 0.75
ALPHA 1.d-3
END

EOS WATER
# ref. density, ref. pressure, water compressibility
DENSITY EXPONENTIAL 1000. 101325. 1.d-8
VISCOSITY CONSTANT 0.864d-3 Pa-s
END

FLUID_PROPERTY
DIFFUSION_COEFFICIENT 1.d-9
END

LINEAR_SOLVER FLOW
SOLVER DIRECT
ZERO_PIVOT_TOL 1.d-20
END

STRATA
REGION all
MATERIAL beam
END

TIME
FINAL_TIME 0.20 day
INITIAL_TIMESTEP_SIZE 1.d-4 day
MAXIMUM_TIMESTEP_SIZE 0.0001 day at 0.d0 day
END

OUTPUT
SNAPSHOT_FILE
TIMES day 0.01 0.04 0.09 0.12
NO_PRINT_INITIAL
FORMAT HDF5
/
END

FLOW_CONDITION initial
TYPE
TEMPERATURE dirichlet
PRESSURE dirichlet
/
TEMPERATURE 25.0d0 C
PRESSURE 101325 Pa
END

FLOW_CONDITION left_end
TYPE
FLUX neumann
TEMPERATURE dirichlet
/
TEMPERATURE 25.0 C
FLUX 0.d0 m/sec
END

FLOW_CONDITION right_end
TYPE
TEMPERATURE dirichlet
FLUX neumann
/
TEMPERATURE 25.0d0 C
FLUX LIST
# liquid_flux = (9.0d-6)*t [m/sec]
TIME_UNITS day
DATA_UNITS m/sec
INTERPOLATION LINEAR
#time  #liquid_flux
0.00d0 0.0d0
1.00d0 9.0d-6
/
END

INITIAL_CONDITION initial
REGION all
FLOW_CONDITION initial
END

BOUNDARY_CONDITION left_end
REGION left_end
FLOW_CONDITION left_end
END

BOUNDARY_CONDITION right_end
FLOW_CONDITION right_end
REGION right_end
END

END_SUBSURFACE


## The PFLOTRAN Input File (RICHARDS Mode)¶

The RICHARDS Mode PFLOTRAN input file can be downloaded here.


SIMULATION
SIMULATION_TYPE SUBSURFACE
PROCESS_MODELS
SUBSURFACE_FLOW flow
MODE RICHARDS
/
/
END

SUBSURFACE

GRID
TYPE structured
NXYZ 10 1 1
DXYZ
2.5d0
1.0d0
1.0d0
END
END

REGION all
COORDINATES
0.0d0 0.0d0 0.0d0
25.0d0 1.0d0 1.0d0
/
END

REGION left_end
FACE WEST
COORDINATES
0.d0 0.d0 0.d0
0.d0 1.0d0 1.0d0
/
END

REGION right_end
FACE EAST
COORDINATES
25.0d0 0.d0 0.d0
25.0d0 1.0d0 1.0d0
/
END

MATERIAL_PROPERTY beam
ID 1
POROSITY 0.20
TORTUOSITY 1.d0
ROCK_DENSITY 2.0d3 kg/m^3
CHARACTERISTIC_CURVES cc1
PERMEABILITY
PERM_X 1.d-14
PERM_Y 1.d-14
PERM_Z 1.d-14
/
END

CHARACTERISTIC_CURVES cc1
SATURATION_FUNCTION VAN_GENUCHTEN
LIQUID_RESIDUAL_SATURATION 0.5d-1
M 0.75
ALPHA 1.d-3
/
PERMEABILITY_FUNCTION MUALEM
LIQUID_RESIDUAL_SATURATION 0.1d0
M 0.5d0
/
PERMEABILITY_FUNCTION MUALEM_VG_GAS
LIQUID_RESIDUAL_SATURATION 0.1d0
GAS_RESIDUAL_SATURATION 0.1d0
M 0.5d0
/
END

EOS WATER
# ref. density, ref. pressure, water compressibility
DENSITY EXPONENTIAL 1000. 101325. 1.d-8
VISCOSITY CONSTANT 0.864d-3 Pa-s
END

FLUID_PROPERTY
DIFFUSION_COEFFICIENT 1.d-9
END

LINEAR_SOLVER FLOW
SOLVER DIRECT
ZERO_PIVOT_TOL 1.d-20
END

STRATA
REGION all
MATERIAL beam
END

TIME
FINAL_TIME 0.20 day
INITIAL_TIMESTEP_SIZE 1.d-4 day
MAXIMUM_TIMESTEP_SIZE 0.0001 day at 0.d0 day
END

OUTPUT
SNAPSHOT_FILE
TIMES day 0.01 0.04 0.09 0.12
NO_PRINT_INITIAL
FORMAT HDF5
/
END

FLOW_CONDITION initial
TYPE
PRESSURE dirichlet
/
PRESSURE 101325 Pa
END

FLOW_CONDITION left_end
TYPE
FLUX neumann
/
FLUX 0.d0 m/sec
END

FLOW_CONDITION right_end
TYPE
FLUX neumann
/
FLUX LIST
# fluid_flux = (9.0d-6)*t [m/sec]
TIME_UNITS day
DATA_UNITS m/sec
INTERPOLATION LINEAR
#time  #fluid_flux
0.00d0 0.0d0
1.00d0 9.0d-6
/
END

INITIAL_CONDITION initial
REGION all
FLOW_CONDITION initial
END

BOUNDARY_CONDITION left_end
REGION left_end
FLOW_CONDITION left_end
END

BOUNDARY_CONDITION right_end
FLOW_CONDITION right_end
REGION right_end
END

END_SUBSURFACE


## The Python Script¶

def flow_transient_1D_BC2ndkind(path,input_prefix,remove,screen_on,pf_exe,
mpi_exe,num_tries):
#==============================================================================#
# Based on:
# Kolditz, et al. (2015) Thermo-Hydro-Mechanical-Chemical Processes in
# Fractured Porous Media: Modelling and Benchmarking, Closed Form Solutions,
# Springer International Publishing, Switzerland.
# Section 2.2.8, pg.20
# "A Transient 1D Pressure Distribution, Time-Dependent Boundary Conditions
# of 2nd Kind"
# With some modification of the parameter values given in Kolditz (2015)
#
# Author: Jenn Frederick
# Date: 08/24/2016
# ******************************************************************************
nxyz = np.zeros(3) + 1
dxyz = np.zeros(3) + 1.
lxyz = np.zeros(3) + 1.
error_analysis = np.zeros(num_tries)
dxyz_record = np.zeros((num_tries,3))
test_pass = False
try_count = 0

# initial discretization values
lxyz[0] = 25.         # [m] lx
nxyz[0] = 10          # [m] nx
dxyz = lxyz/nxyz      # [m]
k = 1.0e-14           # [m2]
mu = 0.864e-3         # [Pa*sec]
por = 0.20
K = 1.0e-8            # [1/Pa]
q = 9.0e-6            # [m/s/day]
p_offset = 101325     # [Pa]
chi = k/(por*K*mu)
ierr = 0

while (not test_pass) and (try_count < num_tries):
print_discretization(lxyz,nxyz,dxyz)
nx = int(nxyz[0]); ny = int(nxyz[1]); nz = int(nxyz[2])
dx = dxyz[0]; dy = dxyz[1]; dz = dxyz[2]
Lx = lxyz[0]; Ly = lxyz[1]; Lz = lxyz[2]
try_count = try_count + 1

x_soln = np.linspace(0.+(dx/2.),Lx-(dx/2.),nx)  # [m]
x_soln = np.concatenate((x_soln,[Lx]),axis=0)   # [m]
p_soln = np.zeros((4,nx+1))                     # [Pa]
x_pflotran = x_soln[0:nx]                       # [m]
p_pflotran = np.zeros((4,nx))                   # [Pa]
t_soln = np.array([0.01,0.04,0.09,0.12])        # [day]

# create the analytical solution
p1 = np.zeros(nx+1)
p2 = np.zeros(nx+1)
i3erfc1 = np.zeros(nx+1)
i3erfc2 = np.zeros(nx+1)
for time in range(4):
t = t_soln[time]*24.0*3600.0  # [sec]
sum_term = np.zeros(nx+1)
sum_term_old = np.zeros(nx+1)
n = 0
epsilon = 1.0
while epsilon > epsilon_value:
p1 = ((((2*n)+1)*Lx)-x_soln)/(2.*math.sqrt(chi*t))
i3erfc1 = (1./12.)*np.sqrt(math.pi)*p1**3*erf(1.0*p1) - (1./12.)*np.sqrt(math.pi)*p1**3 + (1./3.)*p1**2*np.exp(-1.0*p1**2) + 0.5*p1*(-0.5*p1*np.exp(-1.0*p1**2) + 0.25*np.sqrt(math.pi)*erf(1.0*p1)) - 0.125*np.sqrt(math.pi)*p1 + (1./12.)*np.exp(-1.0*p1**2)
p2 = ((((2*n)+1)*Lx)+x_soln)/(2.*math.sqrt(chi*t))
i3erfc2 = (1./12.)*np.sqrt(math.pi)*p2**3*erf(1.0*p2) - (1./12.)*np.sqrt(math.pi)*p2**3 + (1./3.)*p2**2*np.exp(-1.0*p2**2) + 0.5*p2*(-0.5*p2*np.exp(-1.0*p2**2) + 0.25*np.sqrt(math.pi)*erf(1.0*p2)) - 0.125*np.sqrt(math.pi)*p2 + (1./12.)*np.exp(-1.0*p2**2)
sum_term_old = sum_term
sum_term = sum_term_old + (2./math.sqrt(math.pi))*i3erfc1 + (2./math.sqrt(math.pi))*i3erfc2
epsilon = np.max(np.abs(sum_term_old-sum_term))
n = n + 1
p_soln[time,:] = p_offset + ((8*q*(1./(24.*3600.))*math.sqrt(chi*pow(t,3)))/(k/mu))*sum_term

# To calculate the definite integral, use sympy:
# p1, s = sym.symbols('p1 s')
# i3erfc1 = sym.integrate(((pow((s-p1),3))/(3.*2.*1.))*sym.exp(-1.*pow(s,2)),(s,p1,sym.oo))
# p2, s = sym.symbols('p2 s')
# i3erfc2 = sym.integrate(((pow((s-p2),3))/(3.*2.*1.))*sym.exp(-1.*pow(s,2)),(s,p2,sym.oo))

# run PFLOTRAN simulation
run_pflotran(input_prefix,nxyz,dxyz,lxyz,remove,screen_on,pf_exe,mpi_exe)

# load data from HDF5
index_string = 'Time:  1.00000E-02 d/Liquid_Pressure [Pa]'
'/1D_transient_pressure_BC_2nd_kind.h5',index_string,False)
index_string = 'Time:  4.00000E-02 d/Liquid_Pressure [Pa]'
'/1D_transient_pressure_BC_2nd_kind.h5',index_string,False)
index_string = 'Time:  9.00000E-02 d/Liquid_Pressure [Pa]'
'/1D_transient_pressure_BC_2nd_kind.h5',index_string,False)
index_string = 'Time:  1.20000E-01 d/Liquid_Pressure [Pa]'
'/1D_transient_pressure_BC_2nd_kind.h5',index_string,remove)
ierr = check(p_pflotran)

# Convert units [Pa -> MPa]
p_pflotran = p_pflotran/1.e6
p_soln = p_soln/1.e6

max_percent_error = calc_relative_error(p_soln[:,0:nx],p_pflotran,ierr)
record_error(error_analysis,dxyz_record,max_percent_error,dxyz,try_count)
test_pass = does_pass(max_percent_error,try_count,num_tries)
nxyz[0] = nxyz[0]*2.
dxyz = lxyz/nxyz

# Plot the PFLOTRAN and analytical solutions
plot_1D_transient(path,t_soln,'day',x_soln,p_soln,x_pflotran,p_pflotran,
'Distance [m]','Pressure [MPa]',"{0:.2f}".format(max_percent_error))

# Plot error analysis
plot_error(error_analysis,dxyz_record,path,try_count)

# Add test result to report card

return;


Refer to section Python Helper Functions for documentation on the qa_tests_helper module, which defines the helper functions used in the Python script above.

# 1D Transient Flow (Pressure), BCs of 1st & 2nd Kind¶

The Problem Description

The PFLOTRAN Input File (GENERAL Mode)

The PFLOTRAN Input File (TH Mode)

The PFLOTRAN Input File (RICHARDS Mode)

The Dataset

The Python Script

## The Problem Description¶

This problem is adapted from Kolditz, et al. (2015), Thermo-Hydro-Mechanical-Chemical Processes in Fractured Porous Media: Modelling and Benchmarking, Closed Form Solutions, Springer International Publishing, Switzerland. Section 2.2.9, pg.35, “A Transient 1D Pressure Distribution, Non-Zero Initial Pressure, Boundary Conditions of 1st and 2nd Kind.”

The domain is a 100x1x1 meter rectangular beam extending along the positive x-axis and is made up of 50x1x1 hexahedral grid cells with dimensions 2x1x1 meters. The domain is composed of a single material and is assigned the following properties: porosity $$\phi$$ = 0.20; permeability $$k$$ = 1.0e-14 m^2; rock density $$\rho$$ = 2,000 kg/m^3; fluid compressibility $$K$$ = 1.0e-9 1/Pa; fluid viscosity $$\mu$$ = 1.728e-3 Pa-sec.

The pressure is initially distributed according to p(x,t=0)=f(x), where f(x) is defined (in units of MPa) as

\begin{align}\begin{aligned}f(x) = 0 \hspace{0.25in} 0 \leq x < {L \over 10}\\f(x) = {{10x} \over {3L}}-{1 \over 3} \hspace{0.25in} {L \over 10} \leq x < {{4L} \over 10}\\f(x) = 1 \hspace{0.25in} {{4L} \over 10} \leq x < {{6L} \over 10}\\f(x) = 3-{{10x} \over {3L}} \hspace{0.25in} {{6L} \over 10} \leq x < {{9L} \over 10}\\f(x) = 0 \hspace{0.25in} {{9L} \over 10} \leq x \leq L\end{aligned}\end{align}

At the two boundaries, a no fluid flux condition is applied,

\begin{align}\begin{aligned}q(0,t) = 0\\q(L,t) = 0\end{aligned}\end{align}

where L = 100 m. The transient pressure distribution is governed by,

${\phi K} {{\partial p} \over {\partial t}} = {k \over \mu} {{\partial^{2} p} \over {\partial x^{2}}}$

With the initial pressure given, the solution is defined by,

\begin{align}\begin{aligned}p(x,t) = {1 \over 2} + \sum_{n=1}^{\infty} exp\left({-\chi n^2 \pi^2 {t \over L^2}}\right)\left({80 \over {3(n\pi)^2}}\right) cos{{n \pi y} \over L} cos{{n\pi} \over 2} sin{{n\pi} \over 4} sin{{3n\pi} \over 20}\\\chi = {{k} \over {\phi \mu K}}\end{aligned}\end{align}

## The PFLOTRAN Input File (GENERAL Mode)¶

The GENERAL Mode PFLOTRAN input file can be downloaded here.


SIMULATION
SIMULATION_TYPE SUBSURFACE
PROCESS_MODELS
SUBSURFACE_FLOW flow
MODE GENERAL
/
/
END

SUBSURFACE

GRID
TYPE structured
NXYZ 10 1 1
DXYZ
10.0d0
1.0d0
1.0d0
END
END

REGION all
COORDINATES
0.0d0 0.0d0 0.0d0
100.0d0 1.0d0 1.0d0
/
END

REGION left_end
FACE WEST
COORDINATES
0.d0 0.d0 0.d0
0.d0 1.0d0 1.0d0
/
END

REGION right_end
FACE EAST
COORDINATES
100.0d0 0.d0 0.d0
100.0d0 1.0d0 1.0d0
/
END

MATERIAL_PROPERTY beam
ID 1
POROSITY 0.20
TORTUOSITY 1.d0
ROCK_DENSITY 2.0d3 kg/m^3
HEAT_CAPACITY 100. J/kg-C
THERMAL_CONDUCTIVITY_DRY 0.5787037 W/m-C
THERMAL_CONDUCTIVITY_WET 0.5787037 W/m-C
CHARACTERISTIC_CURVES cc1
PERMEABILITY
PERM_X 1.d-14
PERM_Y 1.d-14
PERM_Z 1.d-14
/
END

CHARACTERISTIC_CURVES cc1
SATURATION_FUNCTION VAN_GENUCHTEN
LIQUID_RESIDUAL_SATURATION 0.5d-1
M 0.75
ALPHA 1.d-3
/
PERMEABILITY_FUNCTION MUALEM
LIQUID_RESIDUAL_SATURATION 0.1d0
M 0.5d0
/
PERMEABILITY_FUNCTION MUALEM_VG_GAS
LIQUID_RESIDUAL_SATURATION 0.1d0
GAS_RESIDUAL_SATURATION 0.1d0
M 0.5d0
/
END

EOS WATER
#ref. density [kg/m3], ref. pressure [Pa], water compressibility [1/Pa]
DENSITY EXPONENTIAL 1000. 101325. 1.0d-9
VISCOSITY CONSTANT 1.728d-3 Pa-s
END

FLUID_PROPERTY
DIFFUSION_COEFFICIENT 1.d-9
END

LINEAR_SOLVER FLOW
SOLVER DIRECT
ZERO_PIVOT_TOL 1.d-20
END

STRATA
REGION all
MATERIAL beam
END

TIME
FINAL_TIME 0.50 day
INITIAL_TIMESTEP_SIZE 1.d-4 day
MAXIMUM_TIMESTEP_SIZE 0.0001 day at 0.d0 day
END

OUTPUT
SNAPSHOT_FILE
TIMES day 0.05 0.1 0.25
#NO_PRINT_INITIAL
FORMAT HDF5
/
END

DATASET pressure_initial
HDF5_DATASET_NAME initial
FILENAME ../dataset.h5
END

FLOW_CONDITION initial
TYPE
LIQUID_PRESSURE dirichlet
TEMPERATURE dirichlet
MOLE_FRACTION dirichlet
/
LIQUID_PRESSURE DATASET pressure_initial
TEMPERATURE 25.0 C
MOLE_FRACTION 1.d-10
END

FLOW_CONDITION left_end
TYPE
LIQUID_FLUX neumann
ENERGY_FLUX neumann
GAS_FLUX neumann
/
LIQUID_FLUX 0.d0 m/yr
ENERGY_FLUX 0.d0 W/m^2
GAS_FLUX 0.d0 m/yr
END

FLOW_CONDITION right_end
TYPE
LIQUID_FLUX neumann
ENERGY_FLUX neumann
GAS_FLUX neumann
/
LIQUID_FLUX 0.d0 m/yr
ENERGY_FLUX 0.d0 W/m^2
GAS_FLUX 0.d0 m/yr
END

INITIAL_CONDITION initial
REGION all
FLOW_CONDITION initial
END

BOUNDARY_CONDITION left_end
REGION left_end
FLOW_CONDITION left_end
END

BOUNDARY_CONDITION right_end
FLOW_CONDITION right_end
REGION right_end
END

END_SUBSURFACE


## The PFLOTRAN Input File (TH Mode)¶

The TH Mode PFLOTRAN input file can be downloaded here.


SIMULATION
SIMULATION_TYPE SUBSURFACE
PROCESS_MODELS
SUBSURFACE_FLOW flow
MODE TH
/
/
END

SUBSURFACE

GRID
TYPE structured
NXYZ 10 1 1
DXYZ
10.0d0
1.0d0
1.0d0
END
END

REGION all
COORDINATES
0.0d0 0.0d0 0.0d0
100.0d0 1.0d0 1.0d0
/
END

REGION left_end
FACE WEST
COORDINATES
0.d0 0.d0 0.d0
0.d0 1.0d0 1.0d0
/
END

REGION right_end
FACE EAST
COORDINATES
100.0d0 0.d0 0.d0
100.0d0 1.0d0 1.0d0
/
END

MATERIAL_PROPERTY beam
ID 1
POROSITY 0.20
TORTUOSITY 1.d0
ROCK_DENSITY 2.0d3 kg/m^3
SPECIFIC_HEAT 100. J/kg-C
THERMAL_CONDUCTIVITY_DRY 0.5787037 W/m-C
THERMAL_CONDUCTIVITY_WET 0.5787037 W/m-C
SATURATION_FUNCTION default
PERMEABILITY
PERM_X 1.d-14
PERM_Y 1.d-14
PERM_Z 1.d-14
/
END

SATURATION_FUNCTION default
SATURATION_FUNCTION_TYPE VAN_GENUCHTEN
RESIDUAL_SATURATION 0.5d-1
LAMBDA 0.75
ALPHA 1.d-3
END

EOS WATER
#ref. density [kg/m3], ref. pressure [Pa], water compressibility [1/Pa]
DENSITY EXPONENTIAL 1000. 101325. 1.0d-9
VISCOSITY CONSTANT 1.728d-3 Pa-s
END

FLUID_PROPERTY
DIFFUSION_COEFFICIENT 1.d-9
END

LINEAR_SOLVER FLOW
SOLVER DIRECT
ZERO_PIVOT_TOL 1.d-20
END

STRATA
REGION all
MATERIAL beam
END

TIME
FINAL_TIME 0.50 day
INITIAL_TIMESTEP_SIZE 1.d-4 day
MAXIMUM_TIMESTEP_SIZE 0.0001 day at 0.d0 day
END

OUTPUT
SNAPSHOT_FILE
TIMES day 0.05 0.1 0.25
#NO_PRINT_INITIAL
FORMAT HDF5
/
END

DATASET pressure_initial
HDF5_DATASET_NAME initial
FILENAME ../dataset.h5
END

FLOW_CONDITION initial
TYPE
PRESSURE dirichlet
TEMPERATURE dirichlet
/
PRESSURE DATASET pressure_initial
TEMPERATURE 25.0 C
END

FLOW_CONDITION left_end
TYPE
FLUX neumann
ENERGY_FLUX neumann
/
FLUX 0.d0 m/yr
ENERGY_FLUX 0.d0 W/m^2
END

FLOW_CONDITION right_end
TYPE
FLUX neumann
ENERGY_FLUX neumann
/
FLUX 0.d0 m/yr
ENERGY_FLUX 0.d0 W/m^2
END

INITIAL_CONDITION initial
REGION all
FLOW_CONDITION initial
END

BOUNDARY_CONDITION left_end
REGION left_end
FLOW_CONDITION left_end
END

BOUNDARY_CONDITION right_end
FLOW_CONDITION right_end
REGION right_end
END

END_SUBSURFACE


## The PFLOTRAN Input File (RICHARDS Mode)¶

The RICHARDS Mode PFLOTRAN input file can be downloaded here.


SIMULATION
SIMULATION_TYPE SUBSURFACE
PROCESS_MODELS
SUBSURFACE_FLOW flow
MODE RICHARDS
/
/
END

SUBSURFACE

GRID
TYPE structured
NXYZ 10 1 1
DXYZ
10.0d0
1.0d0
1.0d0
END
END

REGION all
COORDINATES
0.0d0 0.0d0 0.0d0
100.0d0 1.0d0 1.0d0
/
END

REGION left_end
FACE WEST
COORDINATES
0.d0 0.d0 0.d0
0.d0 1.0d0 1.0d0
/
END

REGION right_end
FACE EAST
COORDINATES
100.0d0 0.d0 0.d0
100.0d0 1.0d0 1.0d0
/
END

MATERIAL_PROPERTY beam
ID 1
POROSITY 0.20
TORTUOSITY 1.d0
ROCK_DENSITY 2.0d3 kg/m^3
CHARACTERISTIC_CURVES cc1
PERMEABILITY
PERM_X 1.d-14
PERM_Y 1.d-14
PERM_Z 1.d-14
/
END

CHARACTERISTIC_CURVES cc1
SATURATION_FUNCTION VAN_GENUCHTEN
LIQUID_RESIDUAL_SATURATION 0.5d-1
M 0.75
ALPHA 1.d-3
/
PERMEABILITY_FUNCTION MUALEM
LIQUID_RESIDUAL_SATURATION 0.1d0
M 0.5d0
/
PERMEABILITY_FUNCTION MUALEM_VG_GAS
LIQUID_RESIDUAL_SATURATION 0.1d0
GAS_RESIDUAL_SATURATION 0.1d0
M 0.5d0
/
END

EOS WATER
#ref. density [kg/m3], ref. pressure [Pa], water compressibility [1/Pa]
DENSITY EXPONENTIAL 1000. 101325. 1.0d-9
VISCOSITY CONSTANT 1.728d-3 Pa-s
END

FLUID_PROPERTY
DIFFUSION_COEFFICIENT 1.d-9
END

LINEAR_SOLVER FLOW
SOLVER DIRECT
ZERO_PIVOT_TOL 1.d-20
END

STRATA
REGION all
MATERIAL beam
END

TIME
FINAL_TIME 0.50 day
INITIAL_TIMESTEP_SIZE 1.d-4 day
MAXIMUM_TIMESTEP_SIZE 0.0001 day at 0.d0 day
END

OUTPUT
SNAPSHOT_FILE
TIMES day 0.05 0.1 0.25
#NO_PRINT_INITIAL
FORMAT HDF5
/
END

DATASET pressure_initial
HDF5_DATASET_NAME initial
FILENAME ../dataset.h5
END

FLOW_CONDITION initial
TYPE
PRESSURE dirichlet
/
PRESSURE DATASET pressure_initial
END

FLOW_CONDITION left_end
TYPE
FLUX neumann
/
FLUX 0.d0 m/yr
END

FLOW_CONDITION right_end
TYPE
FLUX neumann
/
FLUX 0.d0 m/yr
END

INITIAL_CONDITION initial
REGION all
FLOW_CONDITION initial
END

BOUNDARY_CONDITION left_end
REGION left_end
FLOW_CONDITION left_end
END

BOUNDARY_CONDITION right_end
FLOW_CONDITION right_end
REGION right_end
END

END_SUBSURFACE


## The Dataset¶

The hdf5 dataset required to define the initial/boundary conditions is created with the following python script called create_dataset.py:

import sys
from h5py import *
import numpy as np

filename = 'dataset.h5'
h5file = File(filename,mode='w')

# 1d line in x
# Pressure initial condition [Pa]
L = 100.
h5grp = h5file.create_group('initial')
h5grp.attrs['Dimension'] = np.string_('X')
# Delta length between points [m]
h5grp.attrs['Discretization'] = [1.]
# Location of origin
h5grp.attrs['Origin'] = [0.]
# Load the dataset values
nx = 101
p_offset = 0.101325   # [MPa]
rarray = np.zeros(nx,'=f8')
for i in range(nx):
if (0. <= i < (L/10.)):
rarray[i] = ( 0. + p_offset ) * 1.0e6  # [Pa]
if ((L/10.) <= i < (4.*L/10.)):
rarray[i] = ( (10./(3.*L))*float(i) - (1./3.) + p_offset ) * 1.0e6  # [Pa]
if ((4.*L/10.) <= i < (6.*L/10.)):
rarray[i] = ( 1. + p_offset ) * 1.0e6  # [Pa]
if ((6.*L/10.) <= i < (9.*L/10.)):
rarray[i] = ( 3. - (10./(3.*L))*float(i) + p_offset ) * 1.0e6  # [Pa]
if ((9.*L/10.) <= i < L):
rarray[i] = ( 0. + p_offset ) * 1.0e6  # [Pa]
h5dset = h5grp.create_dataset('Data', data=rarray)


## The Python Script¶

def flow_transient_1D_BC1st2ndkind(path,input_prefix,remove,screen_on,pf_exe,
mpi_exe,num_tries):
#==============================================================================#
# Based on:
# Kolditz, et al. (2015) Thermo-Hydro-Mechanical-Chemical Processes in
# Fractured Porous Media: Modelling and Benchmarking, Closed Form Solutions,
# Springer International Publishing, Switzerland.
# Section 2.2.9, pg.35
# "A Transient 1D Pressure Distribution, Non-Zero Initial Pressure,
# Boundary Conditions of 1st and 2nd Kind"
# With some modification of the parameter values given in Kolditz (2015)
#
# Author: Jenn Frederick
# Date: 09/09/2016
# ******************************************************************************
nxyz = np.zeros(3) + 1
dxyz = np.zeros(3) + 1.
lxyz = np.zeros(3) + 1.
error_analysis = np.zeros(num_tries)
dxyz_record = np.zeros((num_tries,3))
test_pass = False
try_count = 0

# initial discretization values
lxyz[0] = 100.        # [m] lx
nxyz[0] = 10          # [m] nx
dxyz = lxyz/nxyz      # [m]
k = 1.0e-14           # [m2]
mu = 1.728e-3         # [Pa-s]
por = 0.20
K = 1.0e-9            # [1/Pa]
p_offset = 0.101325   # [MPa]
chi = k/(por*K*mu)
ierr = 0

while (not test_pass) and (try_count < num_tries):
print_discretization(lxyz,nxyz,dxyz)
nx = int(nxyz[0]); ny = int(nxyz[1]); nz = int(nxyz[2])
dx = dxyz[0]; dy = dxyz[1]; dz = dxyz[2]
Lx = lxyz[0]; Ly = lxyz[1]; Lz = lxyz[2]
try_count = try_count + 1

x_soln = np.linspace(0.+(dx/2.),Lx-(dx/2.),nx)      # [m]
x_pflotran = x_soln                                 # [m]
t_soln = np.array([0.05,0.10,0.25,0.50])            # [day]
p_soln = np.zeros((4,nx))                           # [MPa]
p_pflotran = np.zeros((4,nx))                       # [Pa]

# create the analytical solution
for time in range(4):
t = t_soln[time]*24.0*3600.0  # [sec]
sum_term_old = np.zeros(nx)
sum_term = np.zeros(nx)
n = 1
epsilon = 1.0
while epsilon > epsilon_value:
sum_term_old = sum_term
sum_term = sum_term_old + (np.cos(n*math.pi*x_soln/Lx)*np.exp(-chi*pow(n,2)*pow(math.pi,2)*t/pow(Lx,2))*(80./(3.*pow((n*math.pi),2)))*np.cos(n*math.pi/2.)*np.sin(n*math.pi/4.)*np.sin(3.*n*math.pi/20.))
epsilon = np.max(np.abs(sum_term_old-sum_term))
n = n + 1
p_soln[time,:] = 0.50 + sum_term + p_offset

# run PFLOTRAN simulation
run_pflotran(input_prefix,nxyz,dxyz,lxyz,remove,screen_on,pf_exe,mpi_exe)

# load data from HDF5
index_string = 'Time:  5.00000E-02 d/Liquid_Pressure [Pa]'
'/1D_transient_pressure_BC_1st_2nd_kind.h5',index_string,False)
index_string = 'Time:  1.00000E-01 d/Liquid_Pressure [Pa]'
'/1D_transient_pressure_BC_1st_2nd_kind.h5',index_string,False)
index_string = 'Time:  2.50000E-01 d/Liquid_Pressure [Pa]'
'/1D_transient_pressure_BC_1st_2nd_kind.h5',index_string,False)
index_string = 'Time:  5.00000E-01 d/Liquid_Pressure [Pa]'
'/1D_transient_pressure_BC_1st_2nd_kind.h5',index_string,remove)
ierr = check(p_pflotran)

# Convert units [Pa -> MPa]
p_pflotran = p_pflotran/1.e6

max_percent_error = calc_relative_error(p_soln,p_pflotran,ierr)
record_error(error_analysis,dxyz_record,max_percent_error,dxyz,try_count)
test_pass = does_pass(max_percent_error,try_count,num_tries)
nxyz[0] = nxyz[0]*2.
dxyz = lxyz/nxyz

# Plot the PFLOTRAN and analytical solutions
plot_1D_transient(path,t_soln,'day',x_soln,p_soln,x_pflotran,p_pflotran,
'Distance [m]','Pressure [MPa]',"{0:.2f}".format(max_percent_error))

# Plot error analysis
plot_error(error_analysis,dxyz_record,path,try_count)

# Add test result to report card

return;


Refer to section Python Helper Functions for documentation on the qa_tests_helper module, which defines the helper functions used in the Python script above.

# 2D Transient Flow (Pressure), BCs of 1st & 2nd Kind¶

The Problem Description

The PFLOTRAN Input File (GENERAL Mode)

The PFLOTRAN Input File (TH Mode)

The PFLOTRAN Input File (RICHARDS Mode)

The Dataset

The Python Script

## The Problem Description¶

This problem is adapted from Kolditz, et al. (2015), Thermo-Hydro-Mechanical-Chemical Processes in Fractured Porous Media: Modelling and Benchmarking, Closed Form Solutions, Springer International Publishing, Switzerland. Section 2.2.10, pg.37, “A Transient 2D Pressure Distribution, Non-Zero Initial Pressure, Boundary Conditions of 1st and 2nd Kind.”

The domain is a 100x100x1 meter rectangular plate extending along the positive x-axis and y-axis and is made up of 50x50x1 hexahedral grid cells with dimensions 2x2x1 meters. The domain is composed of a single material and is assigned the following properties: porosity $$\phi$$ = 0.20; permeability $$k$$ = 1.0e-14 m^2; rock density $$\rho$$ = 2,000 kg/m^3; fluid compressibility $$K$$ = 1.0e-9 1/Pa; fluid viscosity $$\mu$$ = 1.728e-3 Pa-sec.

The pressure is initially distributed according to p(x,y,t=0)=f(x)*f(y)+ $$p_{offset}$$, where f(x) is defined (in units of MPa) as

\begin{align}\begin{aligned}f(x) = 0 \hspace{0.25in} 0 \leq x < {L \over 10}\\f(x) = {{10x} \over {3L}}-{1 \over 3} \hspace{0.25in} {L \over 10} \leq x < {{4L} \over 10}\\f(x) = 1 \hspace{0.25in} {{4L} \over 10} \leq x < {{6L} \over 10}\\f(x) = 3-{{10x} \over {3L}} \hspace{0.25in} {{6L} \over 10} \leq x < {{9L} \over 10}\\f(x) = 0 \hspace{0.25in} {{9L} \over 10} \leq x \leq L\end{aligned}\end{align}

and f(y) is defined (in units of MPa) as

\begin{align}\begin{aligned}f(y) = 0 \hspace{0.25in} 0 \leq y < {L \over 10}\\f(y) = {{10y} \over {3L}}-{1 \over 3} \hspace{0.25in} {L \over 10} \leq y < {{4L} \over 10}\\f(y) = 1 \hspace{0.25in} {{4L} \over 10} \leq y < {{6L} \over 10}\\f(y) = 3-{{10y} \over {3L}} \hspace{0.25in} {{6L} \over 10} \leq y < {{9L} \over 10}\\f(y) = 0 \hspace{0.25in} {{9L} \over 10} \leq y \leq L\end{aligned}\end{align}

At the north and south boundaries, a no fluid flux condition is applied,

\begin{align}\begin{aligned}q(x,0,t) = 0\\q(x,L,t) = 0\end{aligned}\end{align}

and at the east and west boundaries, a pressure boundary condition is applied,

\begin{align}\begin{aligned}p(0,y,t) = 0\\p(L,y,t) = 0\end{aligned}\end{align}

where L = 100 m and $$p_{offset}$$ = 0.101325 MPa. The transient pressure distribution is governed by,

${\phi K} {{\partial p} \over {\partial t}} = {k \over \mu} \left({ {{\partial^{2} p} \over {\partial x^{2}}} + {{\partial^{2} p} \over {\partial y^{2}}} }\right)$

With the initial pressure given, the solution is defined by,

\begin{align}\begin{aligned}p(x,y,t) = p_1(x,t) p_2(y,t) + p_{offset}\\p_1(x,t) = \sum_{n=1}^{\infty} exp\left({-\chi n^2 \pi^2 {t \over L^2}}\right)\left({80 \over {3(n\pi)^2}}\right) sin{{n \pi x} \over L} sin{{n\pi} \over 2} sin{{n\pi} \over 4} sin{{3n\pi} \over 20}\\p_2(y,t) = {1 \over 2} + \sum_{n=1}^{\infty} exp\left({-\chi n^2 \pi^2 {t \over L^2}}\right)\left({80 \over {3(n\pi)^2}}\right) cos{{n \pi y} \over L} cos{{n\pi} \over 2} sin{{n\pi} \over 4} sin{{3n\pi} \over 20}\\\chi = {{k} \over {\phi \mu K}}\end{aligned}\end{align}

## The PFLOTRAN Input File (GENERAL Mode)¶

The GENERAL Mode PFLOTRAN input file can be downloaded here.


SIMULATION
SIMULATION_TYPE SUBSURFACE
PROCESS_MODELS
SUBSURFACE_FLOW flow
MODE GENERAL
/
/
END

SUBSURFACE

GRID
TYPE structured
NXYZ 40 40 1
DXYZ
2.5d0
2.5d0
1.0d0
END
END

REGION all
COORDINATES
0.0d0 0.0d0 0.0d0
100.0d0 100.0d0 1.0d0
/
END

REGION west_face
FACE WEST
COORDINATES
0.d0 0.d0 0.d0
0.d0 100.0d0 1.0d0
/
END

REGION east_face
FACE EAST
COORDINATES
100.0d0 0.d0 0.d0
100.0d0 100.0d0 1.0d0
/
END

REGION north_face
FACE NORTH
COORDINATES
0.d0 100.0d0 0.d0
100.0d0 100.0d0 1.0d0
/
END

REGION south_face
FACE SOUTH
COORDINATES
0.d0  0.d0  0.d0
100.0d0 0.d0 1.0d0
/
END

MATERIAL_PROPERTY plate
ID 1
POROSITY 0.20
TORTUOSITY 1.d0
ROCK_DENSITY 2.0E3
HEAT_CAPACITY 100. J/kg-C
THERMAL_CONDUCTIVITY_DRY 0.5787037 W/m-C
THERMAL_CONDUCTIVITY_WET 0.5787037 W/m-C
CHARACTERISTIC_CURVES cc1
PERMEABILITY
PERM_X 1.d-14
PERM_Y 1.d-14
PERM_Z 1.d-14
/
END

CHARACTERISTIC_CURVES cc1
SATURATION_FUNCTION VAN_GENUCHTEN
LIQUID_RESIDUAL_SATURATION 0.5d-1
M 0.75
ALPHA 1.d-3
/
PERMEABILITY_FUNCTION MUALEM
LIQUID_RESIDUAL_SATURATION 0.1d0
M 0.5d0
/
PERMEABILITY_FUNCTION MUALEM_VG_GAS
LIQUID_RESIDUAL_SATURATION 0.1d0
GAS_RESIDUAL_SATURATION 0.1d0
M 0.5d0
/
END

EOS WATER
DENSITY EXPONENTIAL 1000. 101325. 1.0d-9
VISCOSITY CONSTANT 1.728d-3 Pa-s
END

FLUID_PROPERTY
DIFFUSION_COEFFICIENT 1.d-9
END

STRATA
REGION all
MATERIAL plate
END

TIME
FINAL_TIME 0.10 day
INITIAL_TIMESTEP_SIZE 1.d-4 day
MAXIMUM_TIMESTEP_SIZE 0.0001 day at 0.d0 day
END

OUTPUT
SNAPSHOT_FILE
#NO_PRINT_INITIAL
TIMES day 0.01 0.04 0.06
#NO_PRINT_FINAL
FORMAT HDF5
/
END

DATASET pressure_initial
HDF5_DATASET_NAME initial
FILENAME ../dataset.h5
END

FLOW_CONDITION initial
TYPE
TEMPERATURE dirichlet
LIQUID_PRESSURE dirichlet
MOLE_FRACTION dirichlet
/
TEMPERATURE 25.0 C
LIQUID_PRESSURE DATASET pressure_initial
MOLE_FRACTION 1.d-20
END

FLOW_CONDITION west_face
TYPE
TEMPERATURE dirichlet
LIQUID_PRESSURE dirichlet
MOLE_FRACTION dirichlet
/
TEMPERATURE 25.0 C
LIQUID_PRESSURE 101325. Pa
MOLE_FRACTION 1.d-20
END

FLOW_CONDITION east_face
TYPE
TEMPERATURE dirichlet
LIQUID_PRESSURE dirichlet
MOLE_FRACTION dirichlet
/
TEMPERATURE 25.0 C
LIQUID_PRESSURE 101325. Pa
MOLE_FRACTION 1.d-20
END

FLOW_CONDITION north_face
TYPE
ENERGY_FLUX neumann
LIQUID_FLUX neumann
GAS_FLUX neumann
/
ENERGY_FLUX 0.d0 W/m^2
LIQUID_FLUX 0.d0 m/yr
GAS_FLUX 0.d0 m/yr
END

FLOW_CONDITION south_face
TYPE
ENERGY_FLUX neumann
LIQUID_FLUX neumann
GAS_FLUX neumann
/
ENERGY_FLUX 0.d0 W/m^2
LIQUID_FLUX 0.d0 m/yr
GAS_FLUX 0.d0 m/yr
END

INITIAL_CONDITION initial
REGION all
FLOW_CONDITION initial
END

BOUNDARY_CONDITION west_face
REGION west_face
FLOW_CONDITION west_face
END

BOUNDARY_CONDITION east_face
FLOW_CONDITION east_face
REGION east_face
END

BOUNDARY_CONDITION north_face
REGION north_face
FLOW_CONDITION north_face
END

BOUNDARY_CONDITION south_face
FLOW_CONDITION south_face
REGION south_face
END

END_SUBSURFACE


## The PFLOTRAN Input File (TH Mode)¶

The TH Mode PFLOTRAN input file can be downloaded here.


SIMULATION
SIMULATION_TYPE SUBSURFACE
PROCESS_MODELS
SUBSURFACE_FLOW flow
MODE TH
/
/
END

SUBSURFACE

GRID
TYPE structured
NXYZ 40 40 1
DXYZ
2.5d0
2.5d0
1.0d0
END
END

REGION all
COORDINATES
0.0d0 0.0d0 0.0d0
100.0d0 100.0d0 1.0d0
/
END

REGION west_face
FACE WEST
COORDINATES
0.d0 0.d0 0.d0
0.d0 100.0d0 1.0d0
/
END

REGION east_face
FACE EAST
COORDINATES
100.0d0 0.d0 0.d0
100.0d0 100.0d0 1.0d0
/
END

REGION north_face
FACE NORTH
COORDINATES
0.d0 100.0d0 0.d0
100.0d0 100.0d0 1.0d0
/
END

REGION south_face
FACE SOUTH
COORDINATES
0.d0  0.d0  0.d0
100.0d0 0.d0 1.0d0
/
END

MATERIAL_PROPERTY plate
ID 1
POROSITY 0.20
TORTUOSITY 1.d0
ROCK_DENSITY 2.0E3
HEAT_CAPACITY 100. J/kg-C
THERMAL_CONDUCTIVITY_DRY 0.5787037 W/m-C
THERMAL_CONDUCTIVITY_WET 0.5787037 W/m-C
SATURATION_FUNCTION default
PERMEABILITY
PERM_X 1.d-14
PERM_Y 1.d-14
PERM_Z 1.d-14
/
END

SATURATION_FUNCTION default
SATURATION_FUNCTION_TYPE VAN_GENUCHTEN
RESIDUAL_SATURATION 0.5d-1
LAMBDA 0.75
ALPHA 1.d-3
END

EOS WATER
DENSITY EXPONENTIAL 1000. 101325. 1.0d-9
VISCOSITY CONSTANT 1.728d-3 Pa-s
END

FLUID_PROPERTY
DIFFUSION_COEFFICIENT 1.d-9
END

STRATA
REGION all
MATERIAL plate
END

TIME
FINAL_TIME 0.10 day
INITIAL_TIMESTEP_SIZE 1.d-4 day
MAXIMUM_TIMESTEP_SIZE 0.0001 day at 0.d0 day
END

OUTPUT
SNAPSHOT_FILE
#NO_PRINT_INITIAL
TIMES day 0.01 0.04 0.06
#NO_PRINT_FINAL
FORMAT HDF5
/
END

DATASET pressure_initial
HDF5_DATASET_NAME initial
FILENAME ../dataset.h5
END

FLOW_CONDITION initial
TYPE
TEMPERATURE dirichlet
PRESSURE dirichlet
/
TEMPERATURE 25.0 C
PRESSURE DATASET pressure_initial
END

FLOW_CONDITION west_face
TYPE
TEMPERATURE dirichlet
PRESSURE dirichlet
/
TEMPERATURE 25.0 C
PRESSURE 101325. Pa
END

FLOW_CONDITION east_face
TYPE
TEMPERATURE dirichlet
PRESSURE dirichlet
/
TEMPERATURE 25.0 C
PRESSURE 101325. Pa
END

FLOW_CONDITION north_face
TYPE
ENERGY_FLUX neumann
FLUX neumann
/
ENERGY_FLUX 0.d0 W/m^2
FLUX 0.d0 m/yr
END

FLOW_CONDITION south_face
TYPE
ENERGY_FLUX neumann
FLUX neumann
/
ENERGY_FLUX 0.d0 W/m^2
FLUX 0.d0 m/yr
END

INITIAL_CONDITION initial
REGION all
FLOW_CONDITION initial
END

BOUNDARY_CONDITION west_face
REGION west_face
FLOW_CONDITION west_face
END

BOUNDARY_CONDITION east_face
FLOW_CONDITION east_face
REGION east_face
END

BOUNDARY_CONDITION north_face
REGION north_face
FLOW_CONDITION north_face
END

BOUNDARY_CONDITION south_face
FLOW_CONDITION south_face
REGION south_face
END

END_SUBSURFACE


## The PFLOTRAN Input File (RICHARDS Mode)¶

The RICHARDS Mode PFLOTRAN input file can be downloaded here.


SIMULATION
SIMULATION_TYPE SUBSURFACE
PROCESS_MODELS
SUBSURFACE_FLOW flow
MODE RICHARDS
/
/
END

SUBSURFACE

GRID
TYPE structured
NXYZ 40 40 1
DXYZ
2.5d0
2.5d0
1.0d0
END
END

REGION all
COORDINATES
0.0d0 0.0d0 0.0d0
100.0d0 100.0d0 1.0d0
/
END

REGION west_face
FACE WEST
COORDINATES
0.d0 0.d0 0.d0
0.d0 100.0d0 1.0d0
/
END

REGION east_face
FACE EAST
COORDINATES
100.0d0 0.d0 0.d0
100.0d0 100.0d0 1.0d0
/
END

REGION north_face
FACE NORTH
COORDINATES
0.d0 100.0d0 0.d0
100.0d0 100.0d0 1.0d0
/
END

REGION south_face
FACE SOUTH
COORDINATES
0.d0  0.d0  0.d0
100.0d0 0.d0 1.0d0
/
END

MATERIAL_PROPERTY plate
ID 1
POROSITY 0.20
TORTUOSITY 1.d0
ROCK_DENSITY 2.0E3
CHARACTERISTIC_CURVES cc1
PERMEABILITY
PERM_X 1.d-14
PERM_Y 1.d-14
PERM_Z 1.d-14
/
END

CHARACTERISTIC_CURVES cc1
SATURATION_FUNCTION VAN_GENUCHTEN
LIQUID_RESIDUAL_SATURATION 0.5d-1
M 0.75
ALPHA 1.d-3
/
PERMEABILITY_FUNCTION MUALEM
LIQUID_RESIDUAL_SATURATION 0.1d0
M 0.5d0
/
PERMEABILITY_FUNCTION MUALEM_VG_GAS
LIQUID_RESIDUAL_SATURATION 0.1d0
GAS_RESIDUAL_SATURATION 0.1d0
M 0.5d0
/
END

EOS WATER
DENSITY EXPONENTIAL 1000. 101325. 1.0d-9
VISCOSITY CONSTANT 1.728d-3 Pa-s
END

FLUID_PROPERTY
DIFFUSION_COEFFICIENT 1.d-9
END

STRATA
REGION all
MATERIAL plate
END

TIME
FINAL_TIME 0.10 day
INITIAL_TIMESTEP_SIZE 1.d-4 day
MAXIMUM_TIMESTEP_SIZE 0.0001 day at 0.d0 day
END

OUTPUT
SNAPSHOT_FILE
#NO_PRINT_INITIAL
TIMES day 0.01 0.04 0.06
#NO_PRINT_FINAL
FORMAT HDF5
/
END

DATASET pressure_initial
HDF5_DATASET_NAME initial
FILENAME ../dataset.h5
END

FLOW_CONDITION initial
TYPE
PRESSURE dirichlet
/
PRESSURE DATASET pressure_initial
END

FLOW_CONDITION west_face
TYPE
PRESSURE dirichlet
/
PRESSURE 101325. Pa
END

FLOW_CONDITION east_face
TYPE
PRESSURE dirichlet
/
PRESSURE 101325. Pa
END

FLOW_CONDITION north_face
TYPE
FLUX neumann
/
FLUX 0.d0 m/yr
END

FLOW_CONDITION south_face
TYPE
FLUX neumann
/
FLUX 0.d0 m/yr
END

INITIAL_CONDITION initial
REGION all
FLOW_CONDITION initial
END

BOUNDARY_CONDITION west_face
REGION west_face
FLOW_CONDITION west_face
END

BOUNDARY_CONDITION east_face
FLOW_CONDITION east_face
REGION east_face
END

BOUNDARY_CONDITION north_face
REGION north_face
FLOW_CONDITION north_face
END

BOUNDARY_CONDITION south_face
FLOW_CONDITION south_face
REGION south_face
END

END_SUBSURFACE


## The Dataset¶

The hdf5 dataset required to define the initial/boundary conditions is created with the following python script called create_dataset.py:

import sys
from h5py import *
import numpy as np
import math
import matplotlib.pyplot as plt

filename = 'dataset.h5'
h5file = File(filename,mode='w')

p0 = 1.             # [MPa]
p_offset = 0.101325 # [MPa]
L = 100.            # [m]
dx = 1.0            # [m]
dy = 1.0            # [m]
dz = 1.0            # [m]

# 2D Surface:
# -----------------------------------------------------------------------------
# Pressure initial condition z=0 face
h5grp = h5file.create_group('initial')
h5grp.attrs['Dimension'] = np.string_('XY')
# Delta length between points [m]
h5grp.attrs['Discretization'] = [dx,dy]
# Location of origin
h5grp.attrs['Origin'] = [0.,0.]
# Load the dataset values
nx = L*dx + 1
ny = L*dy + 1
rarray = np.zeros((nx,ny),'=f8')

fx = np.zeros(nx,'=f8')
for i in range(int(nx)):
if (0. <= i < (L/10.)):
fx[i] = 0.
if ((L/10.) <= i < (4.*L/10.)):
fx[i] = (10./(3.*L))*float(i) - (1./3.)
if ((4.*L/10.) <= i < (6.*L/10.)):
fx[i] = 1.
if ((6.*L/10.) <= i < (9.*L/10.)):
fx[i] = 3. - (10./(3.*L))*float(i)
if ((9.*L/10.) <= i < L):
fx[i] = 0.

fy = np.zeros(ny,'=f8')
for j in range(int(ny)):
if (0. <= j < (L/10.)):
fy[j] = 0.
if ((L/10.) <= j < (4.*L/10.)):
fy[j] = (10./(3.*L))*float(j) - (1./3.)
if ((4.*L/10.) <= j < (6.*L/10.)):
fy[j] = 1.
if ((6.*L/10.) <= j < (9.*L/10.)):
fy[j] = 3. - (10./(3.*L))*float(j)
if ((9.*L/10.) <= j < L):
fy[j] = 0.

for i in range(int(nx)):
for j in range(int(ny)):
rarray[i][j] = ( p0*fx[i]*fy[j] + p_offset ) * 1.0e6  # [Pa]

h5dset = h5grp.create_dataset('Data', data=rarray)



## The Python Script¶

def flow_transient_2D_BC1st2ndkind(path,input_prefix,remove,screen_on,pf_exe,
mpi_exe,num_tries):
#==============================================================================#
# Based on:
# Kolditz, et al. (2015) Thermo-Hydro-Mechanical-Chemical Processes in
# Fractured Porous Media: Modelling and Benchmarking, Closed Form Solutions,
# Springer International Publishing, Switzerland.
# Section 2.2.10, pg.37
# "A Transient 2D Pressure Distribution, Non-Zero Initial Pressure,
# Boundary Conditions of 1st and 2nd Kind"
#
# Author: Jenn Frederick
# Date: 09/09/2016
# ******************************************************************************
nxyz = np.zeros(3) + 1
dxyz = np.zeros(3) + 1.
lxyz = np.zeros(3) + 1.
error_analysis = np.zeros(num_tries)
dxyz_record = np.zeros((num_tries,3))
test_pass = False
try_count = 0

# initial discretization values
lxyz[0] = 100.        # [m] lx
lxyz[1] = 100.        # [m] ly
nxyz[0] = 10          # [m] nx
nxyz[1] = 10          # [m] ny
dxyz = lxyz/nxyz      # [m]
k = 1.0e-14           # [m2]
mu = 1.728e-3         # [Pa-s]
por = 0.20
K = 1.0e-9            # [1/Pa]
p_offset = 0.101325   # [MPa]
p0 = 1.               # [MPa]
chi = k/(por*K*mu)
ierr = 0

while (not test_pass) and (try_count < num_tries):
print_discretization(lxyz,nxyz,dxyz)
nx = int(nxyz[0]); ny = int(nxyz[1]); nz = int(nxyz[2])
dx = dxyz[0]; dy = dxyz[1]; dz = dxyz[2]
Lx = lxyz[0]; Ly = lxyz[1]; Lz = lxyz[2]
try_count = try_count + 1

p_soln = np.zeros((4,nx,ny))                     # [MPa]
p_pflotran = np.zeros((4,nx,ny))                 # [Pa]
t_soln = np.array([0.0,0.04,0.06,0.10])          # [day]
x_soln = np.linspace(0.+(dx/2.),Lx-(dx/2.),nx)   # [m]
y_soln = np.linspace(0.+(dy/2.),Ly-(dy/2.),ny)   # [m]
p1x = np.zeros(int(nx))
p2y = np.zeros(int(ny))

# for time=0, use the actual initial condition as the analytical
# solution, not the analytical solution with t=0:
fx = np.zeros(int(nx))
for i in range(int(nx)):
x = x_soln[i]
if (0. <= x < (Lx/10.)):
fx[i] = 0.
if ((Lx/10.) <= x < (4.*Lx/10.)):
fx[i] = (10./(3.*Lx))*(x) - (1./3.)
if ((4.*Lx/10.) <= x < (6.*Lx/10.)):
fx[i] = 1.
if ((6.*Lx/10.) <= x < (9.*Lx/10.)):
fx[i] = 3. - (10./(3.*Lx))*(x)
if ((9.*Lx/10.) <= x < Lx):
fx[i] = 0.

fy = np.zeros(int(ny))
for j in range(int(ny)):
y = y_soln[j]
if (0. <= y < (Ly/10.)):
fy[j] = 0.
if ((Ly/10.) <= y < (4.*Ly/10.)):
fy[j] = (10./(3.*Ly))*(y) - (1./3.)
if ((4.*Ly/10.) <= y < (6.*Ly/10.)):
fy[j] = 1.
if ((6.*Ly/10.) <= y < (9.*Ly/10.)):
fy[j] = 3. - (10./(3.*Ly))*(y)
if ((9.*Ly/10.) <= y < Ly):
fy[j] = 0.

p_soln_t0 = np.zeros((nx,ny))
for i in range(int(nx)):
for j in range(int(ny)):
p_soln_t0[i][j] = ( p0*fx[i]*fy[j] + p_offset )  # [MPa]

# create the analytical solution for all other times > 0
for time in range(4):
t = t_soln[time]*24.0*3600.0  # [sec]
# create p1y
sum_term_y = np.zeros(int(ny))
sum_term_old_y = np.zeros(int(ny))
n = 1
epsilon = 1
#while n < 5001:
while epsilon > epsilon_value:
sum_term_old_y = sum_term_y
sum_term_y = sum_term_old_y + (np.cos(n*math.pi*y_soln/Ly)*np.exp(-chi*pow(n,2)*pow(math.pi,2)*t/pow(Ly,2))*(80./(3.*pow((n*math.pi),2)))*np.cos(n*math.pi/2.)*np.sin(n*math.pi/4.)*np.sin(3.*n*math.pi/20.))
epsilon = np.max(np.abs(sum_term_old_y-sum_term_y))
n = n + 1
p2y = 0.5 + sum_term_y
# create p1x
sum_term_x = np.zeros(int(nx))
sum_term_old_x = np.zeros(int(nx))
n = 1
epsilon = 1
while epsilon > epsilon_value:
sum_term_old_x = sum_term_x
sum_term_x = sum_term_old_x + (np.sin(n*math.pi*x_soln/Lx)*np.exp(-chi*pow(n,2)*pow(math.pi,2)*t/pow(Lx,2))*(80./(3.*pow((n*math.pi),2)))*np.sin(n*math.pi/2.)*np.sin(n*math.pi/4.)*np.sin(3.*n*math.pi/20.))
epsilon = np.max(np.abs(sum_term_old_x-sum_term_x))
n = n + 1
p1x = sum_term_x
for i in range(int(nx)):
for j in range(int(ny)):
p_soln[time,i,j] = ( p0*p1x[i]*p2y[j] + p_offset ) # [MPa]

p_soln[0,:,:] = p_soln_t0[:,:]

# run PFLOTRAN simulation
run_pflotran(input_prefix,nxyz,dxyz,lxyz,remove,screen_on,pf_exe,mpi_exe)

# load data from HDF5
index_string = 'Time:  0.00000E+00 d/Liquid_Pressure [Pa]'
'/2D_transient_pressure_BC_1st_2nd_kind.h5',index_string,False)
index_string = 'Time:  4.00000E-02 d/Liquid_Pressure [Pa]'
'/2D_transient_pressure_BC_1st_2nd_kind.h5',index_string,False)
index_string = 'Time:  6.00000E-02 d/Liquid_Pressure [Pa]'
'/2D_transient_pressure_BC_1st_2nd_kind.h5',index_string,False)
index_string = 'Time:  1.00000E-01 d/Liquid_Pressure [Pa]'
'/2D_transient_pressure_BC_1st_2nd_kind.h5',index_string,remove)
ierr = check(p_pflotran)

# Convert units [Pa -> MPa]
p_pflotran = p_pflotran/1.e6

max_percent_error = calc_relative_error(p_soln,p_pflotran,ierr)
record_error(error_analysis,dxyz_record,max_percent_error,dxyz,try_count)
test_pass = does_pass(max_percent_error,try_count,num_tries)
nxyz[0] = nxyz[0]*2.
nxyz[1] = nxyz[1]*2.
dxyz = lxyz/nxyz

# Plot the PFLOTRAN and analytical solution:
plot_2D_transient(path,t_soln,'day',x_soln,y_soln,p_soln,p_pflotran,
'Distance [m]','Pressure [MPa]',"{0:.2f}".format(max_percent_error))

# Plot error analysis
plot_error(error_analysis,dxyz_record,path,try_count)

# Add test result to report card

Refer to section Python Helper Functions for documentation on the qa_tests_helper module, which defines the helper functions used in the Python script above.