Flow regime for internal pipe flow
 

Hello Foamers,

I am not 100% sure how I should proceed with my simulations. My case/simulation setup looks as follows:

I have a "zeolite-like" (http://cdn4.explainthatstuff.com/zeo...-structure.jpg) 3d structure inside a tube. The structure itself consists of 10x10x20 cells, which look similar to those from the picture.
I would like to investigate the effect of superficial gas velocity on the flow field. (0.5 - 7m/s)
I think that for the slow velocities, the flow should be laminar. For the higher velocities it will turn to a turbulent flow.

So, the questions which I could not answer myself are:

1) How do I calculate a Re number? Should I calculate a particle Re number instead of the overall tube Re number for estimating y+?

2) When I start laminar (simpleFoam), how can I find out if my flow is in the transition to turbulent flow?

3) Should I use the kklomega model to scan through all the different velocities with the same case setup? Can I use simpleFoam for every velocity or pimpleFoam for the higher velocities?

Any help is highly appreciated...Thank you for your thoughts!

Best regards,

Sebastian