Modeling Swirl Concentrators and Drop Shafts (U. Shamsi)

Dear List Members:

Can you model a swirl concentrator in SWMM/EXTRAN? If not, is there another hydraulic model which can do that?

Also, how would you model a 100 ft deep drop shaft in EXTRAN? Some potential options may be:

1. Model as a conventional manhole
2. Model as a storage junction
3. Model as a bottom outlet (sump) orifice

However, flow through a drop shaft is affected by air entrapment and swirling action of water fall through the shaft which cannot be accounted for using any of the above three options available in Extran. Any more ideas will be appreciated.

Thanks in advance.
Best regards,
Uzair Shamsi
UShamsi@chester-engineers.com