How to zoom in only a region of my geometry
 

Hi

my problem is that my geometry exist of a porous region and a "normal" navier stokes region. So if want to visualise the vecolity i got the following problem. Either i can't see anything in the porous region because the velocity in this region is very very low or i take bigger arrows and cant see anything because then they are m uch too big in the ns region. So how is it possible to zoom in only a part of my geometry?

Thanks

Two ways that I can think of (
 

Two ways that I can think of (depending on how you specify the porous region)

1. Assuming you have a field filter that is 1 in the porous region and 0 elsewhere: in paraFoam use the Calculator-filter and specify a new (cell based) vector-field U*filter. These should give you OK cell-values, but for vectors paraFoam will insist on interpolatin it to the vertices (and propably the values at the porous/free-interface will be wrong)

2. The porous region is specified by a cellSet: use foamToVTK with the -cellSet option to write out the data just for that cellSet and view the data with paraview (or import it into paraFoam in addition to the normal case data)

I should think before posting:
 

I should think before posting: there is a simpler way for the first option (the one with the filter-field): Use the Threshold-filter of paraFoam with values that are only valid in the porous material (in my example 0.5 < filter < 1.5). Voila: You get exactly what you want.

Thank you very much for your f
 

Thank you very much for your fast answer!

bye Nico