inputfile.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- Kaiser, J. W. J., Hoppe, N., Adami, S., & Adams, N. A. (2019).
     An adaptive local time-stepping scheme for multiresolution simulations of hyperbolic conservation laws.
     Journal of Computational Physics: X, 4, 100038.
     Section 4.2 Shock-tube problem of Sod.
     -->
<configuration>
   <domain>
      <!-- Size of a single multi-resolution node on the coarsest level, i.e. level 0. -->
      <nodeSize> 1 </nodeSize>

      <!-- Number of nodes per dimension on the coarsest level.
           Multiplying nodeRatio_x/y/z * nodeSize gives the domain size in x/y/z-direction.
           Multiplying nodeRatio_x/y/z * internal_cells_per_node_and_dimension (adjustable in code: compile_time_constants.h)
           gives the number of cells in x/y/z-direction on the coarsest level. Refinement of the coarse mesh is possible
           by using a multi-resolution scheme. It can be adjusted in the multiResolution section of this inputfile. -->
      <nodeRatio>
         <x> 1 </x>
         <y> 1 </y>
         <z> 1 </z>
      </nodeRatio>

      <!-- Boundary conditions have to be specified for all six faces of the cuboid domain (in 3D). They have to be specified
           for the material as well as the levelset. The faces are denoted according to their geographic orientation:
               East -> positive x direction
               West -> negative x direction
               North -> positive y direction
               South -> negative y direction
               Top -> positive z direction
               Bottom -> negative z direction -->
      <boundaryConditions>
         <material>
            <!-- Types of material boundary conditions:
                     zeroGradient,
                     symmetry,
                     wall,
                     fixedValue. -->
            <west> ZeroGradient </west>
            <east> ZeroGradient </east>
            <!-- In case a fixedValue boundary condition is used, a xml node specifying the
                 fixed prime states has to be added (see example below). -->
            <valuesEast>
               <density> 1.0 </density>
               <velocityX> 0.0 </velocityX>
               <velocityY> 0.0 </velocityY>
               <velocityZ> 0.0 </velocityZ>
               <pressure> 1.0 </pressure>
            </valuesEast>
            <south> ZeroGradient </south>
            <north> ZeroGradient </north>
            <valuesNorth>
               <density> 1.0 </density>
               <velocityX> 0.0 </velocityX>
               <velocityY> 0.0 </velocityY>
               <velocityZ> 0.0 </velocityZ>
               <pressure> 1.0 </pressure>
            </valuesNorth>
            <bottom> symmetry </bottom>
            <top> symmetry </top>
         </material>

         <!-- Levelset boundary conditions. -->
         <levelSet>
            <!--types of level-set boundary conditions:
               zeroGradient,
               symmetry -->
            <west>   symmetry </west>
            <east>   symmetry </east>
            <south>  symmetry </south>
            <north>  symmetry </north>
            <bottom> symmetry </bottom>
            <top>    symmetry </top>
         </levelSet>
      </boundaryConditions>

      <!-- The initial state of each material and the levelset have to be defined. It is possible to use conditional expressions as given below. -->
      <initialConditions>
         <material1>
            if (x &lt; 0.5)
            {
            density : = 1.0;
            velocityX := 0.0;
            velocityY := 0.0;
            velocityZ := 0.0;
            pressure := 1.0;
            }
            else
            {
            density := 0.125;
            velocityX := 0.0;
            velocityY := 0.0;
            velocityZ := 0.0;
            pressure := 0.1;
            }
         </material1>

         <material2>
            density := 1.0;
            velocityX := 0.75;
            velocityY := 0.0;
            velocityZ := 0.0;
            pressure := 1.0;
         </material2>

         <!-- Xml node defining the levelset input. Possible types are: functional, STL, parametric. For each type, a set of parameters must be specified.  -->
         <levelSet1>
            <type> functional </type>
            <input> phi := 1.0; </input>
            <boundingBox>
               <xMin> 0.0 </xMin>
               <xMax> 1.0 </xMax>
               <yMin> 0.0 </yMin>
               <yMax> 1.0 </yMax>
               <zMin> 0.0 </zMin>
               <zMax> 1.0 </zMax>
            </boundingBox>
         </levelSet1>
      </initialConditions>
   </domain>

   <!-- Xml nodes defining the equation of state and its properties for each material. -->
   <!-- Explanation:
        type: Choose the equation of state that has to be applied.
              Possible choices are: StiffenedGas or WaterlikeFluid (Tait), NobleAbelStiffenedGas, StiffenedGasComplete.
              For each equation of state a set of parameter must be specified.
        -->
   <materials>
      <!-- The number of materials in the simulation. Note: Currently, 2 is the maximum. -->
      <numberOfMaterials>  2  </numberOfMaterials>
      <material1>
         <!-- available options are: Fluid, SolidBoundary -->
	 <type> Fluid </type>
	 <equationOfState>
            <type> StiffenedGas </type>
            <gamma>               1.4   </gamma>
            <backgroundPressure>  0.0   </backgroundPressure>
	 </equationOfState>
         <properties>
            <specificHeatCapacity> 0.0 </specificHeatCapacity>
            <thermalConductivity>
               <fixedValue> 0.0 </fixedValue>
               <model>
                  <name> Constant </name>
                  <parameter>
                     <lambdaConstant> 10.0 </lambdaConstant>
                  </parameter>
               </model>
            </thermalConductivity>
            <shearViscosity>
               <fixedValue> 0.0 </fixedValue>
               <model>
                  <name> PowerLaw </name>
                  <parameter>
                     <consistencyFactor> 1.0 </consistencyFactor>
                     <powerLawExponent> 0.0 </powerLawExponent>
                  </parameter>
               </model>
            </shearViscosity>
            <bulkViscosity> 0.0 </bulkViscosity>
         </properties>
      </material1>

      <material2>
	 <!-- available options are: Fluid, SolidBoundary -->
	 <type> Fluid </type>
         <equationOfState>
            <type> WaterlikeFluid </type>
            <gamma>               1.4   </gamma>
            <A> 1.0 </A>
            <B> 1.0 </B>
            <rho0>  1.0   </rho0>
	 </equationOfState>
         <properties>
            <specificHeatCapacity> 0.0 </specificHeatCapacity>
            <thermalConductivity>
               <fixedValue> 0.0 </fixedValue>
               <model>
                  <name> Constant </name>
                  <parameter>
                     <lambdaConstant> 0.0 </lambdaConstant>
                  </parameter>
               </model>
            </thermalConductivity>
            <shearViscosity>
               <fixedValue> 0.0 </fixedValue>
               <model>
                  <name> PowerLaw </name>
                  <parameter>
                     <consistencyFactor> 1.0 </consistencyFactor>
                     <powerLawExponent> 0.0 </powerLawExponent>
                  </parameter>
               </model>
            </shearViscosity>
            <bulkViscosity> 0.0 </bulkViscosity>
         </properties>
      </material2>
   </materials>

   <materialPairings>
      <material1_2>
         <surfaceTensionCoefficient>
            <fixedValue> 0.0 </fixedValue>
            <model>
               <name> Constant </name>
               <parameter>
                  <sigmaConstant> 0.0 </sigmaConstant>
               </parameter>
            </model>
         </surfaceTensionCoefficient>
      </material1_2>
   </materialPairings>

   <!-- Define a volume force, due to gravity in this case, in x/y/z direction.  -->
   <sourceTerms>
      <gravity>
         <x> 0 </x>
         <y> 0 </y>
         <z> 0 </z>
      </gravity>
   </sourceTerms>

   <!-- Employ a multi-resolution scheme as described in the paper cited at the top of this file. -->
   <multiResolution>
      <!-- Number of possible refinements. Uniform meshes are obtained for maximumLevel = 0 or 1 -->
      <maximumLevel> 2 </maximumLevel>

      <refinementCriterion>
         <!-- The reference error on the given reference level for the wavelet-based refinement decisions. -->
         <epsilonReference> 0.01 </epsilonReference>
         <!-- The level on which the stated epsilon value should be enforced.
              Note: allowed values are 0-13. -->
         <levelOfEpsilonReference> 1  </levelOfEpsilonReference>
      </refinementCriterion>
   </multiResolution>

   <!-- Block where the start, end time and Courant–Friedrichs–Lewy number of the simulation are defined. -->
   <timeControl>
      <startTime> 0.0  </startTime>
      <endTime>   0.2  </endTime>
      <CFLNumber> 0.6 </CFLNumber>
   </timeControl>

   <!-- ALPACA internally calculates with nondimensionalized values. Reference values used for
        nondimensionalization have to be specified to length scales, velocity, density and temperature. -->
   <dimensionalization>
      <lengthReference>       1.0  </lengthReference>
      <velocityReference>     1.0  </velocityReference>
      <densityReference>      1.0  </densityReference>
      <temperatureReference>  1.0  </temperatureReference>
   </dimensionalization>

   <!-- This xml node specifies whether a simulation should be restarted or not, and all relevant parameters that
            have to be specified. -->
   <restart>
      <!-- xml node to restore the simulation from a snapshot  -->
      <restore>
         <!-- Mode: Off, Soft (if file exists) OR Forced -->
         <mode> Off </mode>
         <!-- The path to the .h5 file that has to be used to restore the simulation. Only used if restore is active -->
         <fileName> inputfile/restart/restart_***.h5 </fileName>
      </restore>
      <!-- xml node to specify details about the snapshots writing-->
      <snapshots>
         <!-- Type how the snapshots are written: Off, Stamps, Interval OR IntervalStamps -->
         <type> Stamps </type>
         <!-- in wall seconds. Only used if type Interval or IntervalStamps is active. -->
         <interval> 3600 </interval>
         <!-- Number of interval snapshots that are kept. Timestamp-based snapshots are always kept -->
         <intervalsToKeep> 2 </intervalsToKeep>
         <!-- Time stamps for specific snapshots. Only used if type Stamps or IntervalStamps is active. -->
         <stamps> <!-- always kept -->
            <!-- <ts1> 0.1 </ts1> -->
            <!-- <ts2> 0.2 </ts2> -->
         </stamps>
      </snapshots>
   </restart>

   <!-- Below xml node is used to specify output related settings. The output is always written in Xdmf/Hdf5 format. -->
   <output>
      <!-- Factor to manipulate the naming of the output files. TimeInName = physical time * timeNamingFactor-->
      <timeNamingFactor> 1.e0 </timeNamingFactor>
      <!-- Output settings used for the general output of the full domain (also in Debug mode (adjustable in code: debug_profile_settings.h)) -->
      <standardOutput>
         <!-- Specify whether output should be written with a fixed interval (Interval), specific timestamps (Timestamps) or both (IntervalStamps).
              To disable aoutput use Off. -->
         <type> Interval </type>
         <!-- The interval with which output is written in case interval output is active. Neglected otherwise. -->
         <interval>  1e-6 </interval>
         <!-- If output at timestamps is active, the timestamps can be specified below. Neglected otherwise. -->
	      <stamps>
            <ts1> 0.0004 </ts1>
            <ts2> 0.0006 </ts2>
            <ts3> 0.0008 </ts3>
            <ts4> 0.0010 </ts4>
            <ts5> 0.0012 </ts5>
            <ts6> 0.0014 </ts6>
            <ts7> 0.0016 </ts7>
            <ts8> 0.0018 </ts8>
            <ts9> 0.05   </ts9>
            <ts10>0.15    </ts10>
            <ts11>0.2    </ts11>
            <ts12>0.4    </ts12>
         </stamps>
      </standardOutput>
      <!-- Output settings used for the output of only interface nodes. Details about specifications, see above in standardOutput. -->
      <interfaceOutput>
         <type> Interval </type> <!--Off, Interval, Stamps OR IntervalStamps-->
         <interval>  1e-6 </interval>
	      <stamps>
            <ts1>  0.0004 </ts1>
            <ts2>  0.0006 </ts2>
         </stamps>
      </interfaceOutput>
   </output>

</configuration>