added tutorial for foam-extend

quickstart/README.md

@@ -115,6 +115,12 @@ You can also run OpenFOAM in parallel: `./run.sh -parallel`.
 
 In serial, the simulation should take less than a minute to compute (simulated time: 2.5s).
 
+{% note %}
+While we recommend starting with the latest OpenFOAM version from openfoam.com,
+this case can alternatively be executed with foam-extend.
+For that, replace `run-openfoam.sh` with `run-foam-extend.sh` in the `run.sh` script.
+{% endnote %}
+
 ## Visualizing the results
 
 You can visualize the simulation results of the `Fluid` participant using ParaView and loading the (empty) file `fluid-openfoam/fluid-openfoam.foam`. The rigid body does not generate any readable output files, but the OpenFOAM data should be enough for now: click "play" in ParaView, the flap should already be moving! 🎉

quickstart/fluid-openfoam/0/U

@@ -22,11 +22,14 @@ boundaryField
     top
     {
         type            noSlip;
+        value           uniform (0 0 0);
+        // Note: Values in noSlip are only needed for foam-extend
     }
 
     bottom
     {
         type            noSlip;
+        value           uniform (0 0 0);
     }
 
     inlet

quickstart/fluid-openfoam/constant/dynamicMeshDict

@@ -14,6 +14,8 @@ motionSolverLibs ("libfvMotionSolvers.so");
 solver      displacementLaplacian;
 // OpenFOAM9 or newer: rename "solver" to "motionSolver"
 
+diffusivity uniform; // Only relevant to foam-extend
+
 displacementLaplacianCoeffs {
     diffusivity quadratic inverseDistance (flap);
 }

quickstart/fluid-openfoam/system/controlDict

@@ -3,13 +3,17 @@ FoamFile
     version     2.0;
     format      ascii;
     class       dictionary;
+    location    "system";
     object      controlDict;
 }
 
+// Note: This file is prepared to run with the latest supported version of OpenFOAM.com.
+// The tutorials/tools/run-foam-extend.sh script can modify this and other files to run with foam-extend.
+// The format of the file (e.g., linked libraries in one line each) is at parts important to the script.
+
 application     pimpleFoam;       // latest OpenFOAM
 // application     pimpleDyMFoam; // OpenFOAM v1712, OpenFOAM 5.x, or older
 
-
 startFrom           startTime;
 
 startTime           0;
@@ -36,7 +40,10 @@ timeFormat          general;
 
 timePrecision       8;
 
-libs ("libpreciceAdapterFunctionObject.so");
+libs
+(
+    "libpreciceAdapterFunctionObject.so"
+);
 functions
 {
     forces
@@ -47,6 +54,13 @@ functions
         rho                 rhoInf;
         log                 true;
         rhoInf              10;
+        // The following entries are only relevant to foam-extend
+        functionObjectLibs  ( "libforces.so" );
+        outputControl       timeStep;
+        outputInterval      1;
+        pName               p;
+        UName               U;
+        rhoName             rhoInf;
         CofR                (0 0 0);
     }
 

quickstart/fluid-openfoam/system/fvSchemes

@@ -21,6 +21,7 @@ divSchemes
 {
     default         none;
     div(phi,U)      Gauss linearUpwind grad(U);
+    div((nuEff*dev(T(grad(U))))) Gauss linear;  // Only relevant to foam-extend
     div((nuEff*dev2(T(grad(U))))) Gauss linear;
 }
 

quickstart/fluid-openfoam/system/fvSolution

@@ -14,6 +14,10 @@ solvers
         tolerance        1e-6;
         relTol           1e-4;
         smoother         DICGaussSeidel;
+         // The following entries are only relevant to foam-extend
+        agglomerator    faceAreaPair;
+        nCellsInCoarsestLevel 10;
+        mergeLevels 1;
     }
 
     pFinal
@@ -78,3 +82,17 @@ potentialFlow
 {
     nNonOrthogonalCorrectors 1;
 }
+
+// The relaxationFactors and fieldBounds are only relevant to foam-extend
+relaxationFactors
+{
+    U          0.7;
+    UFinal     1;
+}
+
+fieldBounds
+{
+    p -1e5 1e5;
+    U 100;
+}
+

quickstart/fluid-openfoam/system/preciceDict

@@ -36,4 +36,5 @@ interfaces
 FSI
 {
   rho rho [1 -3 0 0 0 0 0] 1000;
+  nu nu [0 2 -1 0 0 0 0] 0.001; // Only relevant to foam-extend
 }

tools/run-foam-extend.sh

@@ -0,0 +1,47 @@
+#!/usr/bin/env sh
+set -e # Not setting -u as it gets triggered by the OpenFOAM RunFunctions
+
+# Prepare an (intentionally empty) .foam file for the ParaView OpenFOAM reader
+CASENAME="$(pwd | xargs basename)"
+touch "$CASENAME.foam"
+
+# Keep a backup of the files to modify
+echo "backing up the original files (copies: 0/U.orig, system/controlDict.orig, constant/dynamicMeshDict.orig)"
+cp 0/U 0/U.orig
+cp system/controlDict system/controlDict.orig
+cp constant/dynamicMeshDict constant/dynamicMeshDict.orig
+
+# Modify code for foam-extend
+echo "modifying everything now"
+sed -i "s/noSlip;/noSlipWall;/g" 0/U
+sed -i "s,application     pimpleFoam;,//application     pimpleFoam;,g" system/controlDict
+sed -i "s,// application     pimpleDyMFoam;,application     pimpleDyMFoam;,g" system/controlDict
+sed -i '41i\ \ \ \ "liblduSolvers.so"' system/controlDict
+sed -i '41i\ \ \ \ "libforces.so"' system/controlDict
+sed -i "s,writeCompression    off,writeCompression    uncompressed,g" system/controlDict
+
+sed -i "s/libfvMotionSolvers\./libfvMotionSolver\./g" constant/dynamicMeshDict
+
+# OpenFOAM run functions: getApplication, getNumberOfProcessors
+# shellcheck disable=SC1090 # This is an OpenFOAM file which we don't need to check
+. "${WM_PROJECT_DIR}/bin/tools/RunFunctions"
+solver=$(getApplication | cut -f 1 -d " " | sed '\~//~d')
+if [ "${1:-}" = "-parallel" ]; then
+    procs=$(getNumberOfProcessors)
+    decomposePar -force
+    mpirun -np "${procs}" "${solver}" -parallel
+    reconstructPar
+else
+    ${solver}
+fi
+
+# Reverse code for OpenFOAM
+#rm -rf constant/polyMesh
+#sed -i "s/noSlipWall;/noSlip;/g" 0/U
+#sed -i "s,application     pimpleDyMFoam;,// application     pimpleDyMFoam;,g" system/controlDict
+#sed -i "s,//application     pimpleFoam;,application     pimpleFoam;,g" system/controlDict
+#sed -i '/   "liblduSolvers.so"/d' system/controlDict
+#sed -i '/   "libforces.so/d' system/controlDict
+#sed -i "s,writeCompression    uncompressed,writeCompression    off,g" system/controlDict
+#
+#sed -i "s/libfvMotionSolver\./libfvMotionSolvers\./g" constant/dynamicMeshDict