[Tutankhamun]

hi i modelled a case where 2 sewerpipes flow with maximum capacity (fully filled, heavy rain maybe), were the one pipe flows in the other one (the bigger one). now i simulated it with 2 mass flow inlets so that 15 ltr comes out... 50% over maximum capacity of the pipe. but now i think it maybe not realistic... should not be a backflow/backlog there because normally there should be only 10ltr in the bigger pipe and the 5 cannot enter, or only partially... it is no extra pressure on it. that result looks like i can give as much water as i want in the channel.. only result is higher flowvelocity (Q=v*a)... but is that realistic.?






..................5 ltr
....................\
....10 ltr ______\_____ 15 ltr ?