Balancing steady flow at junctions

[Jennifer Kampa]

I am trying to convert an unsteady model to a steady model for permit purposes. The model has a junction where a portion of the flow is diverted, and then ~300′ downstream of the 1st junction there is a 2nd junction where more flow gets diverted. We are trying to use approved FIS hydrology (HEC-1), but revising the rating curves for the diversions. The HEC-1 output flows are then input into the HEC-RAS steady flow profiles, the model is run, and the W.S. Elev and E.G. Elev are compared in the junction output table. The HEC-1 rating curves are adjusted again based on whether more or less flow needs to be diverted at each junction, and the iterative process continues. I have not been able to balance the flows after almost 30 iterations, so I am hoping someone has successfully done this before. I have tried using flow optimization, but that was unsuccessful. Do you have any suggestions on how to balance flows when you have 2 junctions with diversions close together?

[Luis Partida]

The optimization process should have gotten you there. The rule when using optimization is that you are supposed to take the resultant flows from the optimized flow file in Standard table-1 and enter those as flows in the steady state flow editor. THEN you have to turn optimization OFF with the new flows and re run the model. If this doesnt work and you know the amount of flow diverting in the original model you could just add them as static reductions within the steady state flow editor

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