Two recent e-mails question SWMM's lack of ability to simulate real time controls. Just want to let everyone know that SWMM44 EXTRAN can simulate these in a fashion.
A new orifice type has been added that opens or closes based on the head in any junction in the model. The orifice shape can be either rectangular or circular. The orifice can be configured to have a fixed invert (represent a sluice gate) or a fixed crown (inflatable dam). The maximum rate of orifice opening or closing can be specified. The orifice opening can be a linear function of head. Alternatively, orifice can be configured to open or close when specified head conditions are met. The user specifies the "open" and "closed" dimensions. I believe that the code and inputs is flexible enough to handle most real-world cases.
A new pump type 4 can be used to simulate flow control devices where flow is a function of the upstream head. This could be used where the stage/discharge relationship is known say for a detention pond outlet or for a CSO control device such as a vortex valve where the stage vs. flow relationship is defined.
Just another note: the most recent version of the program (not yet delivered to Dr. Huber) has an option to limit the maximum flow in any closed conduit in the system. This is specified through the SPHI variable on the C1 lines.
Any comments or suggestions about these features are welcome.
Charles I. Moore, P.E.
MOORECI@CDM.COM
Linear Mode
