Problem to edit a rule

[Anonymous]

Hi,
I’ve got a problem to write an operation rule : I read the Users Manual (chapter 16) but I didn’t find who to solve the problem.

In my 1D/2D model, there is an Inline Structure with 2 gates (Gate#1 and Gate#2). The end of the model is the sea (at XS – 8000), and the boundary condition at XS – 8000 is a stage hydrograph, based on the predictable tide.
I would like to edit a rule for the Inline Structure like :
* Simulation value : Hsea (sea level) = WS Elevation at XS – 8000 at (simulation time + 6h)
* If (‘Hsea’ >= 5.71) Then
Gate.Opening(Gate#1) = max opening (at simulation time)
Gate.Opening(Gate#2) = max opening (at simulation time)
I would like the 2 gates to be 100% opened during 6 hours before the moment when the sea level is more than 5.71 m. Then, when the sea level come to be more than 5.71 m, the gates must close. My issue concerns the time definition : how to make understand to the model that it have to consider the sea level 6hours before the simulation time, and from that moment, if the condition is fulfilled, the gates are fully opened during 6 hours.

I don’t know if my question is really clear and I apologize for my bad english, but I hope someone could be help me with this…
Thank you

[Anonymous]

Create a dummy reach and attach a boundary condition that has the tide levels six hours sooner.

HEC-RAS comes with example data sets. (If you didn’t install them, they should be available under Help.) Find the project \1D Unsteady Flow Hydraulics\Rule Operations\RuleAndTimeSeries.prj. This example has Rules and it uses a dummy reach as part of the rules.

Make a copy of your stage hydrograph and move it six hours sooner.
So if your data is:

1000 4.0
1100 4.5
1200 5.1
1300 5.6
1400 6.1
1500 6.2

Make a copy that looks like:

0400 4.0
0500 4.5
0600 5.1
0700 5.6
0800 6.1
0900 6.2

Use this stage boundary on your dummy reach. Your rules can then look at this stage to know what the tide will be in six hours.

[Anonymous]

Thank you very much for your advice.
I downloaded the project “RuleAndTimeSeries.prj” and the exemple of the 2 dummies storage areas with the dummy connection is pretty clear. I’ll use it to solve my problem.

[Author]

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