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Structure Width

Mon, 03/27/2017 - 6:44pm — Benjamin
I have been puzzled by the complexity of a model that I inherited. I have a system of two reservoirs, where one reservoir has a 3x3 matrix of 9 valves to pass water from one reservoir to another (on the upstream face of the dam). If I have 3 inlets that have the same inlet center-line elevation, and all exist in the same segment, would it make any difference to model it as is, or to simplify the model with a single intake at that one elevation? Therefore my 3x3 matrix of intakes would become a 3x1 matrix of intakes? My hesitation is that if this was true, then why would there be a card for structure width for use in LINE type structures? Thanks
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Hydrodynamics
Mon, 04/24/2017 - 2:01pm — Benjamin

I believe I have the answer to my question. For reference to anyone else, modeling several intakes is indeed important (at least in terms of preserving the width of the gates). So, although the intake center-lines are all the same, and that the segment is laterally well mixed (meaning all 3 intakes will pull from the same laterally mixed water), the extent of which layers the intake draws from is dependent on how big the inlets are. The height of the inlets is the same, but the widths become cumulative depending on what gates are open. If we imagine a case where 1 inlet gate (at a given elevation) is open vs. all 3 inlet gates (again at the same elevation), we can imagine for a given flow through the intake, the velocities will increase for the one gate scenario, as the same amount of water must pass through a smaller opening (1 gate instead of 3). This will effect the "cone of influence" of which layers that this water is drawn from, which will inevitably play a role in temperature balance.