Create a System Curve in EPANet for a network 1

[flowless]

Hi everyone,
I'm trying to generate a system curve from EPANet. I found a reply by Fel3 explaining how to do this here Link and here Link but I have a different situation...

The problem is that my system is ill-conditioned at node 3 and the both resevoir seem to be closed at initial time. I think it's because there's no reservoir in the second part of the model but I didn't know where to put it cause I have a distibution network with many nodes and many demands. I really don't know if and how it's possible to generate a system curve in this case... please help

Thanks for any advice! Model is attached

 

[fel3]

When you have two disconnected systems in one model, each system requires its own tank or reservoir.. This is to establish a boundary condition in each system for the hydraulic grade line.

BTW, both links are to the same thread. I suspect one of the links was supposed to go here:

https://www.eng-tips.com/viewthread.cfm?qid=458044

============
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[flowless]

Thank fel3 for your reply and yes the second link had to lead you there, my fault.
I understand what you mean but how can I do that in this case? do i have to connect every link (with a demand>0) to resevoir?

 

[fel3]

You do not have to connect every link to a reservoir. You just need one reservoir in each disconnected system. Because your larger system has no reservoir (or tank), there is no way to establish the HGLs within it.

If the larger (downstream) system in your model doesn't actually have a reservoir or tank, then you are pumping into a closed system. However, most closed systems that I have seen have a pressure relief of some sort. If yours has one, then that relief can be used as the reservoir. For example, you can use the upstream pressure setting on a pressure sustaining valve. Convert it to an HGL and that becomes the elevation of your reservoir.

============
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill