Visualisation of isocurves
 

Hi. I'm Architect who is learning about wind phenomena around buildings.
I've already run a wind simulation with OpenFoam using ODS-Studio and I had some beautiful visualization with Paraview
My question is about how to visualise isocurves of shelter parameter around the model like the picture in this paper:
http://i.imgur.com/oIKw4C5.png
http://i.imgur.com/OmUXWWj.png
The paper is by Wisse, J. A. A Philosophy for Teaching Wind in the Built Environment Energy and Buildings, 1988, 11, 157-161
http://www.sciencedirect.com/science...78778888900321

I would like to visualise similar isocurves representing the ratio of wind speed around the model to the input wind speed. I don't have clear idea how Paraview shows isocurves or isosurfaces in my simulation. Apparently, it shows pressure, but I like areas showing a ratio of speed.
Is it possible to set up Paraview for this kind of visualisation? I don't know if my question makes sense (my English is second language).

Regards