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OpenFOAM is an open-source Computational Fluid Dynamics (CFD) software.

This Kubernetes chart will deploy OpenFOAM for distributed computing using OpenMPI, which runs a cluster of worker nodes controlled by a single master node.

The latest container images are available from

You can also build OpenFOAM from a custom source using Dockerfiles, starting with

Helm Chart on GitLab


Install the app through Rancher.

Login with SSH

Open the App openfoam in Rancher, and check which external port to use for SSH.

ssh -p 30684 -t '/openfoam/run'

Available users are openfoam and root.

Shared volume

Master and worker nodes share the same home directory /home/openfoam by rook-ceph-fs persistent volume.

Sync a file system with SSHFS

Connect with SSHFS

sshfs ~/local_dir -C -p 30684

Download with S3 storage

To download result data, rclone can be used with ICE Connect S3 Storage

zip -r ~/motorBike
rclone copy s3:my-bucket/

S3 access and secret keys are configured in ~/.config/rclone/rclone.conf

Add/remove worker nodes

Worker nodes are listed in /kube-openmpi/generated/hostfile

openfoam-master.openfoam slots=64 max_slots=64
openfoam-worker-0.openfoam slots=64 max_slots=64
openfoam-worker-1.openfoam slots=64 max_slots=64

slots represent max available CPU threads, max_slots limits over-subscription, as in the OpenMPI documentation.

By default, worker nodes reserve 1 CPU thread but are allowed to use the maximum number of threads if available. Increase/decrease the number of workers through Rancher.

increase the number of workers

Nodes can access each other by SSH, e.g.

openfoam@openfoam-master:~$ ssh openfoam-worker-0.openfoam

Run motorBike demo

Log in and perform the initial setup on the master node

cp -r "$FOAM_TUTORIALS"/incompressible/simpleFoam/motorBike ~
cd ~/motorBike
mkdir -p constant/triSurface
cp -f "$FOAM_TUTORIALS"/resources/geometry/motorBike.obj.gz constant/triSurface/
cp system/decomposeParDict.6 system/decomposeParDict
ls -d processor* | xargs -I {} \rm -rf ./{}/0
ls -d processor* | xargs -I {} \cp -r 0.orig ./{}/0 > /dev/null 2>&1
ln -s /kube-openmpi/generated/hostfile .

The following foamJob sends OpenMPI commands to worker nodes

foamJob -screen -parallel snappyHexMesh -overwrite
foamJob -screen -parallel topoSet
foamJob -screen -parallel patchSummary
foamJob -screen -parallel potentialFoam -writephi
foamJob -screen -parallel checkMesh -writeFields '(nonOrthoAngle)' -constant
time foamJob -screen -parallel simpleFoam

Reconstruct the decomposed mesh

reconstructParMesh -constant
reconstructPar -latestTime

Graphical tools such as paraFoam are not supported in the Kubernetes app, because of performance limitations. It is recommended to download the results locally for post-processing.

scp -r -P 30684 /home/myname


Last update: 2023-08-15
Created: 2022-12-27