OGS
sandwich_fixed_power.prj
<OpenGeoSysProject>
  <meshes>
    <mesh>sandwich.vtu</mesh>
  </meshes>
  <processes>
    <process>
      <name>HeatTransportBHE</name>
      <type>HEAT_TRANSPORT_BHE</type>
      <integration_order>2</integration_order>
      <process_variables>
        <process_variable>temperature_soil</process_variable>
        <process_variable>temperature_BHE1</process_variable>
      </process_variables>
      <borehole_heat_exchangers>
        <borehole_heat_exchanger>
          <type>1U</type>
          <flow_and_temperature_control>
            <type>FixedPowerConstantFlow</type>
            <flow_rate>1e-3</flow_rate>
            <power>10</power>
          </flow_and_temperature_control>
          <borehole>
            <length>3.0</length>
            <diameter>0.2</diameter>
          </borehole>
          <grout>
            <density>2190.0</density>
            <porosity>0.0</porosity>
            <specific_heat_capacity>1781</specific_heat_capacity>
            <thermal_conductivity>1.4</thermal_conductivity>
          </grout>
          <pipes>
            <inlet>
              <diameter>0.02</diameter>
              <wall_thickness>0.003</wall_thickness>
              <wall_thermal_conductivity>0.43</wall_thermal_conductivity>
            </inlet>
            <outlet>
              <diameter>0.02</diameter>
              <wall_thickness>0.003</wall_thickness>
              <wall_thermal_conductivity>0.43</wall_thermal_conductivity>
            </outlet>
            <distance_between_pipes>0.075</distance_between_pipes>
            <longitudinal_dispersion_length>0.001</longitudinal_dispersion_length>
          </pipes>
          <refrigerant>
            <density>1000</density>
            <viscosity>0.005</viscosity>
            <specific_heat_capacity>4000</specific_heat_capacity>
            <thermal_conductivity>0.5</thermal_conductivity>
            <reference_temperature>293.15</reference_temperature>
          </refrigerant>
        </borehole_heat_exchanger>
      </borehole_heat_exchangers>
    </process>
  </processes>
  <media>
    <medium id="0">
      <phases>
        <phase>
          <type>AqueousLiquid</type>
          <properties>
            <property>
              <name>phase_velocity</name>
              <type>Constant</type>
              <value>0 0 0</value>
            </property>
            <property>
              <name>specific_heat_capacity</name>
              <type>Constant</type>
              <value>3795</value>
            </property>
            <property>
              <name>density</name>
              <type>Constant</type>
              <value>1000</value>
            </property>
          </properties>
        </phase>
        <phase>
          <type>Solid</type>
          <properties>
            <property>
              <name>specific_heat_capacity</name>
              <type>Constant</type>
              <value>2000</value>
            </property>
            <property>
              <name>density</name>
              <type>Constant</type>
              <value>1000</value>
            </property>
          </properties>
        </phase>
        <phase>
          <type>Gas</type>
          <properties>
            <property>
              <name>specific_heat_capacity</name>
              <type>Constant</type>
              <value>1000</value>
            </property>
            <property>
              <name>density</name>
              <type>Constant</type>
              <value>2500</value>
            </property>
          </properties>
        </phase>
      </phases>
      <properties>
        <property>
          <name>porosity</name>
          <type>Constant</type>
          <value>0</value>
        </property>
        <property>
          <name>thermal_conductivity</name>
          <type>Constant</type>
          <value>2.0</value>
        </property>
        <property>
          <name>thermal_longitudinal_dispersivity</name>
          <type>Constant</type>
          <value>5</value>
        </property>
        <property>
          <name>thermal_transversal_dispersivity</name>
          <type>Constant</type>
          <value>0.5</value>
        </property>
      </properties>
    </medium>
  </media>
  <time_loop>
    <processes>
      <process ref="HeatTransportBHE">
        <nonlinear_solver>basic_picard</nonlinear_solver>
        <convergence_criterion>
          <type>DeltaX</type>
          <norm_type>NORM2</norm_type>
          <reltol>1.e-6</reltol>
        </convergence_criterion>
        <time_discretization>
          <type>BackwardEuler</type>
        </time_discretization>
        <time_stepping>
          <type>FixedTimeStepping</type>
          <t_initial>0.0</t_initial>
          <t_end>600</t_end>
          <timesteps>
            <pair>
              <repeat>10</repeat>
              <delta_t>60</delta_t>
            </pair>
          </timesteps>
        </time_stepping>
      </process>
    </processes>
    <output>
      <type>VTK</type>
      <prefix>sandwich_fixed_power</prefix>
      <timesteps>
        <pair>
          <repeat>1</repeat>
          <each_steps>1</each_steps>
        </pair>
      </timesteps>
      <variables>
        <variable>temperature_soil</variable>
        <variable>temperature_BHE1</variable>
      </variables>
    </output>
  </time_loop>
  <parameters>
    <parameter>
      <name>T0</name>
      <type>Constant</type>
      <value>293.15</value>
    </parameter>
    <parameter>
      <name>T_soil_imposed</name>
      <type>Constant</type>
      <value>273.15</value>
    </parameter>
    <parameter>
      <name>T0_BHE</name>
      <type>Constant</type>
      <values>293.15 293.15 293.15 293.15</values>
    </parameter>
  </parameters>
  <process_variables>
    <process_variable>
      <name>temperature_soil</name>
      <components>1</components>
      <order>1</order>
      <initial_condition>T0</initial_condition>
      <boundary_conditions />
    </process_variable>
    <process_variable>
      <name>temperature_BHE1</name>
      <components>4</components>
      <order>1</order>
      <initial_condition>T0_BHE</initial_condition>
    </process_variable>
  </process_variables>
  <nonlinear_solvers>
    <nonlinear_solver>
      <name>basic_picard</name>
      <type>Picard</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 cg -p jacobi -tol 1e-16 -maxiter 10000</lis>
      <eigen>
        <solver_type>BiCGSTAB</solver_type>
        <precon_type>ILUT</precon_type>
        <max_iteration_step>1000</max_iteration_step>
        <error_tolerance>1e-16</error_tolerance>
      </eigen>
      <petsc>
        <prefix>gw</prefix>
        <parameters>-gw_ksp_type cg -gw_pc_type bjacobi -gw_ksp_rtol 1e-16 -gw_ksp_max_it 10000</parameters>
      </petsc>
    </linear_solver>
  </linear_solvers>
</OpenGeoSysProject>