Quick and dirty Rayleigh-Taylor instability

The Rayleigh-Taylor instability is a well-known benchmarck for CFD codes. The idea is to start with two phases, on on top of the other, the lighter one being underneath. The interface is slightly perturbed, and this plume appears. I describe a quick and dirty way of getting this instability.

OpenFOAM cheatlist

A quick cheatsheet for OpenFOAM. In italics, things that are useful but not part of OpenFOAM proper. Interesting read: The OpenFOAM Technology Primer

Sites

• OpenFOAM official site
• the OpenFOAM foundation
• The OpenFOAM Extend Project
• OpenFOAM forums on CDF-online forums
• sourceflux
• Unofficial OpenFOAM wiki

Shortcuts to directories

(type “alias” to reveal these)

• run (go to own’s running directory)
• foam
• foamfv
• foam3rdParty (hit <tab> for these longish commands!)
• tut
• app
• sol
• util
• lib
• src

Environment variables

• echo $FOAM_ <tab>  (directories)
• echo $WM_ <tab>  (building, aka compiling, settings)

Mesh

• Generation
  • blockMesh
  • snappyHexMesh
  • funkySetFields (part of the swak4Foam project, together with groovyBC)
  • foamyHexMesh
  • foamyQuadMesh
  • cfMesh (provided by creative fields )
• Import / export
  • foamMeshToFluent
  • fluentMeshToFoam, etc …
• Operations
  • refineHexMesh
  • transformPoints
  • makeAxialMesh
  • collapseEdges
  • autoPatch
  • mirorMesh
• Properties
  • checkMesh

Fields

• setFields
• topoSet
• patchAverage
• patchIntegrate
• vorticity
• yPlusRAS
• yPlusLES
• boxTurb
• applyBoundaryLayer
• R
• wallShearStress

Help

• foamHelp (e.g. foamHelp boudary -field U)

Postprocessing

• sample
• paraview
• probeLocations

Solvers

• icoFoam
• interFoam
• many, many others

Running

• foamJob
• decomposePar
• reconstructPar
• mpirun
• nohup

Building

• foamNew source App …
• doxygen doxyfile
• gdb
• valgrind
• wmake
• wclean
• aliases for settings: wm32, wm64, wmSP, wmDP, wmSET, wmUNSET