A pretty picture. For more pretty pictures, see here.


Here you can read about my offerings with respect to mechanical engineering simulation of fluids, a.k.a. computational fluid dynamics (CFD). First, some general remarks:

  • I strive to apply the general principle that what SimScale can do, I can do, too (in many cases, my in-house computer with 16 3.4 GHz cores will be used).
  • In addition, I can do everything that the software system OpenFOAM (read more here) can do.
  • A standard delivery will consist of results files that can be read by the free postprocessor ParaView (read more here)
  • - plus a harddisk file for either Docker or a virtual computer, enabling the customer to redo the entire analysis at home (read more here)
  • - meaning that already on the first delivery, the customer is close to having the entire procedure templated or automated!

A standard delivery is sparse when it comes to documentation. Further documentation may be produced by the hour.

Additional possibilities

Through the years, I have coded a number of modifications of OpenFOAM procedures for water flow in a rotating coordinate system. For instance:

  • I discovered that the sharp transition between water and air required by the VOF theory could without detection blur and ruin the whole analysis. Quantifying this erroneous behavior and displaying it graphically proved to be an indispensable quality check.
  • Large regions of air at standstill could develop an instability that no one else seems to have documented (possibly an attractor). Entering a very small amount of nonlinear Darcy seepage behavior quenched the problem.
  • Swarms of simulation data have been collected and handled by statistics analysis software (see here).
  • And then there is of course more deliberate scripting and automation.
  • Finally, I have invented a CFD teaching device which has attracted some positive attention.

Do not hesitate to bring forward any wish of having existing procedures modified to serve a special purpose. Until now, I have programmed in bash, Python, Visual Basic, Matlab, Fortran, C, C++ and C# to get things done.

Tailor-made meshes

My old-school upbringing tends to make me frown at today's idiom of spray-painting millions of cells onto an unprepared geometry and then mindlessly turn the crank. In Gmsh (see also here), I believe to have found a tool that I can use for the rest of my career. Especially when heading towards automation, it is a very bad idea not to create meshes and leverage symmetries according to a plan.

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Website for the defunct company Simxon by Kim Ravn-Jensen is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Permissions beyond the scope of this license may be available at kim@ravn-jensen.dk.