[Many]

Hi everyone,

I need to study the flow uniformity in a pipe with different inlet/outlets. The pipe have variable porous media length, so I will have to choose the configuration of the best design regarding flow uniformity and pressure drop.

Which is the best way to that?

I have read that residence time is a good indicator of flow uniformity. Lower gradients in the outlet plane of porous media indicates a more uniform flow.

Other parameter that is used in flow uniformity index (gamma), which is something like a deviation from mean velocity value with respect to local velocity of cells in a plane.

The question is that the results for residence time suggest that the higher the porous media length is, the more uniform the flow is as well(lower difference between maximum and minimum value of residence time in the outlet plane). And the results from gamma index suggest that flow uniformity in the outlet plane of porous media is better when the length of porous media is shorter (gamma value increases at the outlet of the porous media when length of porous media decreases).

So this two values are given inconsistent results from my point of view.

Could somebody give some light about this? Is it possible to obtain this result? Can I use residence time at the outlet of porous media as a criteria for uniformity of the flow? Or should I go for gamma? Has my results physical meaning?

Maybe it is better to plot flow uniformity index along the whole pipe and select the top curve )closest to 1)...

Thanks for your comments!

Regards,

Many