Dear All,
I am running a simple 1D problem with the LiquidFlow Module of OGS.
Problem:
On the left boundary (inlet), I am applying a curve scaled Flow Rate BC, and on the right boundary (outlet) I am applying a pressure BC (p=0 MPa).
When plotting the flow rate over time at the inlet in ParaView, the resulting curve (blue and red) does not fit the expected curve (orange).
When using a constant flow rate, the result was similar:
Does anyone has a suggestion for this problem?
Implementation of the FlowRate BC at Inlet
<parameter>
<name>p_in</name>
<type>CurveScaled</type>
<curve>curve_p_in</curve>
<parameter>p_in_start</parameter>
</parameter>
<parameter>
<name>p_in_start</name>
<type>Constant</type>
<value>1</value>
</parameter>
<curve>
<name>curve_p_in</name>
<coords>1 80000 80001 6000000</coords>
<values>1e-9 1e-9 0.5e-9 0.5e-9</values>
</curve>
...
<boundary_conditions>
<boundary_condition>
<geometrical_set>line</geometrical_set>
<geometry>left</geometry>
<type>Neumann</type>
<parameter>p_in</parameter>
</boundary_condition>
Whole .prj-file configuration:
<?xml version='1.0' encoding='ISO-8859-1'?>
<OpenGeoSysProject>
<!-- <meshes>
<mesh>mesh/bulk_mesh_with_k.vtu</mesh>
<mesh>mesh/Sub_Xmax_0_0.vtu</mesh>
<mesh>mesh/Sub_Xmin_0_0.vtu</mesh>
</meshes> -->
<mesh>mesh/bulk_mesh_with_k.vtu</mesh>
<geometry>mesh/bulk_mesh_with_k.gml</geometry>
<processes>
<process>
<name>LiquidFlow</name>
<type>LIQUID_FLOW</type>
<integration_order>2</integration_order>
<!-- <dimension>1</dimension> -->
<process_variables>
<process_variable>pressure</process_variable>
</process_variables>
<secondary_variables>
<secondary_variable internal_name="darcy_velocity" output_name="v"/>
<!-- <secondary_variable internal_name="k" output_name="k"/> -->
</secondary_variables>
<specific_body_force>0.0</specific_body_force>
<!-- <mass_lumping>true</mass_lumping> -->
</process>
</processes>
<media>
<medium id="0">
<phases>
<phase>
<type>AqueousLiquid</type>
<properties>
<property>
<name>viscosity</name>
<type>Constant</type>
<value>1.006e-3 </value>
</property>
<property>
<name>density</name>
<type>Constant</type>
<value>998.2</value>
</property>
</properties>
</phase>
</phases>
<properties>
<property>
<name>permeability</name>
<type>Parameter</type>
<parameter_name>k</parameter_name>
</property>
<!-- <property>
<name>permeability</name>
<type>Constant</type>
<value>1e-16</value>
</property> -->
<property>
<name>reference_temperature</name>
<type>Constant</type>
<value>293.15</value>
</property>
<property>
<name>porosity</name>
<type>Constant</type>
<value>0.01</value>
</property>
<property>
<name>storage</name>
<type>Constant</type>
<value>8.730336828513545e-12</value>
</property>
</properties>
</medium>
<!-- <medium id="1">
<phases>
<phase>
<type>AqueousLiquid</type>
<properties>
<property>
<name>viscosity</name>
<type>Constant</type>
<value>1.006e-3 </value>
</property>
<property>
<name>density</name>
<type>Constant</type>
<value>998.2</value>
</property>
</properties>
</phase>
</phases>
<properties>
<property>
<name>permeability</name>
<type>Constant</type>
<value>1e-18</value>
</property>
<property>
<name>reference_temperature</name>
<type>Constant</type>
<value>293.15</value>
</property>
<property>
<name>porosity</name>
<type>Constant</type>
<value>0.01</value>
</property>
<property>
<name>storage</name>
<type>Constant</type>
<value>1.416e-11</value>
</property>
</properties>
</medium> -->
</media>
<time_loop>
<processes>
<process ref="LiquidFlow">
<nonlinear_solver>basic_picard</nonlinear_solver>
<convergence_criterion>
<type>DeltaX</type>
<norm_type>NORM2</norm_type>
<abstol>1.e-6</abstol>
</convergence_criterion>
<time_discretization>
<type>BackwardEuler</type>
</time_discretization>
<time_stepping>
<type>EvolutionaryPIDcontroller</type>
<t_initial>0</t_initial>
<t_end>500000</t_end>
<!-- <t_end>10000</t_end> -->
<dt_guess>50</dt_guess>
<dt_min>50</dt_min>
<dt_max>2e3</dt_max>
<rel_dt_min>0.05</rel_dt_min>
<rel_dt_max>4</rel_dt_max>
<tol>1</tol>
</time_stepping>
</process>
</processes>
<output>
<type>VTK</type>
<prefix>Flow2D_LiquidFlow_</prefix>
<timesteps>
<pair>
<repeat>1</repeat>
<each_steps>1</each_steps>
</pair>
</timesteps>
<variables>
<variable>pressure</variable>
<variable>v</variable>
<variable>k</variable>
</variables>
<suffix>_ts_{:timestep}_t_{:time}</suffix>
<fixed_output_times>1 5e3 10e3 80e3 100e3 140e3 160e3</fixed_output_times>
</output>
</time_loop>
<parameters>
<!-- Model parameters -->
<parameter>
<name>zero</name>
<type>Constant</type>
<value>0</value>
</parameter>
<parameter>
<name>k</name>
<type>MeshElement</type>
<field_name>k</field_name>
</parameter>
<parameter>
<name>p_test</name>
<type>Constant</type>
<!-- <value>1e5</value> -->
<value>0</value>
</parameter>
<parameter>
<name>pressure_ic</name>
<type>Constant</type>
<!-- <value>1e5</value> -->
<value>0e+00</value>
</parameter>
<parameter>
<name>p_in</name>
<type>CurveScaled</type>
<curve>curve_p_in</curve>
<parameter>p_in_start</parameter>
</parameter>
<parameter>
<name>p_in_start</name>
<type>Constant</type>
<value>1</value>
</parameter>
<parameter>
<name>p_in_const</name>
<type>Constant</type>
<value>1e-9</value>
</parameter>
<parameter>
<name>v_test</name>
<type>Constant</type>
<value>1e-8</value>
<!-- <value>2e6</value> -->
</parameter>
<parameter>
<name>p_out</name>
<type>Constant</type>
<value>0e+00</value>
</parameter>
<parameter>
<name>kappa1</name>
<type>Constant</type>
<values>1.e-12</values>
</parameter>
</parameters>
<curves>
<!-- Pressure curve -->
<!-- <curve>
<name>curve_p_in</name>
<coords>1 80000 80001 6000000</coords>
<values>1e+06 1e+06 0.5e+06 0.5e+06</values>
</curve> -->
<curve>
<name>curve_p_in</name>
<coords>1 80000 80001 6000000</coords>
<values>1e-9 1e-9 0.5e-9 0.5e-9</values>
</curve>
<!-- <curve>
<name>curve_p_in</name>
<coords>1 50 51 70000 70001 90000 90001 140000 140001 500e3</coords>
<values>0 0 1.5e-9 1.5e-9 0 0 0.5e-9 0.5e-9 0 0</values>
</curve> -->
</curves>
<process_variables>
<process_variable>
<name>pressure</name>
<components>1</components>
<order>1</order>
<initial_condition>pressure_ic</initial_condition>
<!-- Version with .vtu meshes
<boundary_conditions>
<boundary_condition>
<mesh>Sub_Xmin_0_0</mesh>
<type>Neumann</type>
<parameter>v_test</parameter>
</boundary_condition>
<boundary_condition>
<mesh>Sub_Xmax_0_0</mesh>
<type>Dirichlet</type>
<parameter>p_out</parameter>
</boundary_condition>
</boundary_conditions> -->
<!-- Version with GMESH -->
<boundary_conditions>
<boundary_condition>
<geometrical_set>line</geometrical_set>
<geometry>left</geometry>
<type>Neumann</type>
<parameter>p_in_const</parameter>
</boundary_condition>
<boundary_condition>
<geometrical_set>line</geometrical_set>
<geometry>right</geometry>
<type>Dirichlet</type>
<parameter>p_out</parameter>
</boundary_condition>
</boundary_conditions>
<!-- <source_terms>
<source_term>
<mesh>Sub_Edge_X_neg_0_0</mesh>
<type>Nodal</type>
<parameter>p_in</parameter>
</source_term>
</source_terms> -->
</process_variable>
</process_variables>
<!-- Setting from Embedded Fracture Modell -->
<!-- <nonlinear_solvers>
<nonlinear_solver>
<name>basic_newton</name>
<type>Newton</type>
<max_iter>100</max_iter>
<linear_solver>general_linear_solver</linear_solver>
</nonlinear_solver>
</nonlinear_solvers>
<linear_solvers>
<linear_solver>
<name>general_linear_solver</name>
<lis>-i SparseLU -p ilu -tol 1e-8 -maxiter 10000</lis>
<eigen>
<solver_type>SparseLU</solver_type>
<precon_type>DIAGONAL</precon_type>
<max_iteration_step>10000</max_iteration_step>
<error_tolerance>1e-8</error_tolerance>
</eigen>
</linear_solver>
</linear_solvers> -->
<!-- ============================================================= -->
<!-- Setting from Liquid Flow: -->
<nonlinear_solvers>
<nonlinear_solver>
<name>basic_picard</name>
<type>Picard</type>
<max_iter>10</max_iter>
<linear_solver>general_linear_solver</linear_solver>
</nonlinear_solver>
</nonlinear_solvers>
<linear_solvers>
<linear_solver>
<name>general_linear_solver</name>
<lis>-i cg -p jacobi -tol 1e-20 -maxiter 10000</lis>
<eigen>
<solver_type>CG</solver_type>
<precon_type>DIAGONAL</precon_type>
<max_iteration_step>10000</max_iteration_step>
<error_tolerance>1e-20</error_tolerance>
</eigen>
<petsc>
<prefix>lf</prefix>
<parameters>-lf_ksp_type cg -lf_pc_type bjacobi -lf_ksp_rtol 1e-16 -lf_ksp_max_it 10000</parameters>
</petsc>
</linear_solver>
</linear_solvers>
</OpenGeoSysProject>
```
