[Hiroya Matsuura]

I use OpenFoam studying for car analysis.

I don't understand how to indicate vorticity magnitude.

I want to see that vortical strctures with various scales are developed around the car.

Please let me know what should I do?

[clapointe]

There are a few function objects that should be useful. The first can be used to compute vorticity (https://github.com/OpenFOAM/OpenFOAM...ty/vorticity.H) as a volume field that you can then view, for example, using paraview. Another option to view vortical structures is by using the Q (https://github.com/OpenFOAM/OpenFOAM...ts/field/Q/Q.H) or Lambda2 (https://github.com/OpenFOAM/OpenFOAM...bda2/Lambda2.H) function objects. These will compute volume fields that can be used to identify coherent structures, where Q > 0 or Lamba2 < 0, respectively if I remember correctly. This appears to be a good reference : http://www.georgehaller.com/reprints/vortex.pdf.

All of the function objects I mentioned can be used as a post process step so you don't have to rerun a simulation.

Caelan

[fumiya]

In aerodynamics simulations, the total pressure coefficients fields are also used to check the regions of vortical structures that cause drag increase.

Best regards,
Fumiya