How is the Maximum Link Flow Applied in SWMM 5?

Subject:  How is the Maximum Link Flow Applied in SWMM 5?

How is the Maximum Link Flow Applied in SWMM 5?

by dickinsonre
Subject:  How is the Maximum Link Flow Applied in SWMM 5?
The maximum flow limit for a link applies to the kinematic wave and the dynamic wave solution.   The inflow to the link  in the kinematic wave solution is limited (Figure 1) but the calculated link flow is limited in the dynamic wave solution after the link flow (Figure 2):
1.       Is checked using the Culvert Inlet Equations (optional)
2.      The normal flow equation is checked (internally optional depending on the Normal flow options) and
3.      The Picard iteration solution under relaxation parameter (always 0.5) is applied (Figure 3).
Figure 1.  Kinematic Wave Solution Limits the Inflow to  the Link Maximum limit.
Figure 2. Dynamic Wave Solution link  flow limit.
Figure 3.  The Link  flow in the dynamic wave solution has three checks at each iteration in a time step.

Comments

Post a Comment

Popular posts from this blog

Water Analogies for Divergence, Curl and Gradient

Image
Comment: A really nice water analogy for the field properties Divergence, Curl and Gradient from the Blog Starts With a Bang

....it's pretty mathematically intensive, but what's missing from most textbooks and E&M courses are physical explanations of what the mathematics means. For instance, I've started teaching about fields, and pretty much every textbook out there goes on and on about the properties of fields. They say you can do three things to fields, take the gradient, divergence, orcurl of them. (Are you asleep yet? I'm sorry!) What do these things mean? An easy way to picture it is in terms of water. If you placed a drop of water anywhere on, say,Earth, the magnitude and direction of how it rolls down is the gradient of the Earth's elevation. If you let that drop of water flow, as it goes downhill, it can either spread out or converge to a narrower stream. When we quantify that, that's what the divergence of the field is. And finally, when that water is …
Read more

Soffit Level

Image
Soffit Level
(pipe technology)The top point of the inside open section of a pipe or box conduit.
The soffit is the highest point of the internal surface of a pipe or culvert at any cross-section. The soffit is also referred to as the pipe obvert.
So it is not quite the Crown of the Pipe.  Here is an image I found that hopefully explains it better.


Read more

SWMM 5 Error Messages

Engine Error Number Description ERROR 101: memory allocation error.                                                                                             ERROR 103: cannot solve KW equations for Link                                                                                   ERROR 105: cannot open ODE solver.                                                                                              ERROR 107: cannot compute a valid time step.                                                                                     ERROR 108: ambiguous outlet ID name for Subcatchment
Read more