K71: droplet with obstacle: prepare the case

  • Which cooperation partners in K71 are responsible for the experiment with the droplet and the cylindrical obstacle? Check slides on Confluence.

  • Contact the cooperation partners and ask them for information on the experiment. What is the largest droplet that they use and what is the largest obstacle, to keep the range of lengthscales for first simulations as small as possibe? What are the fluid properties? Can they do inclined plate experiments? Describe the setup and put all this info into the wiki page of B01 here.

  • Install freecad

  • Create the solution domain in freecad: box with an incline and on it the cylindrical obstacle. See if you can save a macro or a python script in freecad that generates this geometry - we need a way to parameterize simulations easily, to change domain size and obstacle size easily and programmatically.

There is no need to tilt the domain, create a horizontal surface with the cylindrical obstacle, we can rotate the mesh easily in OpenFOAM with an app

  • Install cfmesh as openfoam module: run ./Allwmake in openfoam/modules that should do it. Go to cfmesh/userGuide, read and understand how cfMesh works, we'll be using cartesianMesh to mesh the domain.

  • Mesh the domain

  1. Start with the 2D damBreak case: $FOAM_TUTORIALS/multiphase/interIsoFoam/damBreak (could be slightly different path)

  2. Export a triangulation of the CAD domain from freecad: there is a surface mesh generator inside freecad, find it and use it to generate a surface triangular mesh as STL.

  3. Run feature edge detection on the STL from freecad using an angle of 60 degrees (cfMesh user guide). View the generated STL patches in paraview to understand which patch belongs to which boundary condition.

  4. Use cfmesh to rename the patches into boundary, inclinedWall, obstacle.

  5. Set parameters for cartesianMesh and mesh the boundary with boundary layers, edge detection, etc.

  • Automatize the mesh generation using python

  1. Make sure we can create the STL from the CAD in freecad by exporting a python script and making it take arguments that we want: position and size of obstacle, domain dimensions, etc.

  2. Make sure cfMesh mesh generation and patch identification run automatically.

  • Initialize the case and run interIsoFoam...
Edited by Asghar, Muhammad Hassan