update openfoam example

examples/OpenFOAM/readme.md

@@ -22,3 +22,31 @@ sudo chmod -R 777 motorBike
 cd motorBike
 ./Allrun
 ```
+
+
+To run on more cores, the domains needs to be updated including the hierarchy:
+
+```
+sudo mount -t cvmfs software.eessi.io /cvmfs/software.eessi.io
+source /cvmfs/software.eessi.io/versions/2023.06/init/bash
+ml load OpenFOAM
+source $FOAM_BASH
+export OMP_NUM_THREADS=4
+
+mkdir outputs
+cd outputs
+
+# Brute force copy, since this comes from a read-only, non-owned filesystem
+sudo cp -r $FOAM_TUTORIALS/incompressibleFluid/motorBike .
+sudo chown -R `id -u`:`id -g` motorBike
+sudo chmod -R 777 motorBike 
+
+
+cd motorBike
+
+sed -i 's/numberOfSubdomains  8;/numberOfSubdomains  16;/' motorBike/system/decomposeParDict
+sed -i 's/    n               (4 2 1);/    n               (4 4 1);/' motorBike/system/decomposeParDict
+
+
+./Allrun
+```