Pipe flow discrepancy

[Brett Robinson]

Hello, just a quick question.

When modeling a pipe network say, with an inlet at the top of the network with a few manholes downstream of the inlet, assuming uniform pipe size. The documentation mentions 'pipe flow' solely as directly from the Rational method and yet 12d is applying a loss factor after each chamber. (Say upstream of manhole it is 100L/s and after the manhole it is 95L/s) Does it calculate the flow rate through the pipe network from the Rational Method and then modify that pipe flow through a second iteration of calculations?

Thanks,
Brett

[Owen Thornton]

The Rational Method accounts for the pipe travel time, which adds to the Tc of the catchment.
So, flow rates from a catchment, will attenuate as they move further and further downstream, through the pipe system.
This is to synthesize the storage effect of the pipes.

[Brett Robinson]

Oh of course, appreciate for clearing that up Owen.