[igorce]

I appreciate your support. Thank you very much

[igorce]

Thank you cameron.
I have additional simple short question.
Why the software give us output hydrographs with negative values?

[igorce]

I hope is more clear now. Exactly like you say, if i need more stabiliti results i must use smaller time step.
This is big area who is modeled with DX=5, DY=5 computation mesh (2.033.000 cells) , Computation interval is 2 second, mapping output interval is 6 second, hydrograph output interval is 1 minute.

Here i will repet my dilemma: Till now my computer work (you can see, from 06jul2018 10:03:48AM) cca 75 hours.
Did someone have experience with this?
Did you make analyse with this software more than 5 days?

[igorce]

Yes, the geometry is different because it is a different project, but it is not important that, i think this is the procedure for conducting a hydraulic analysis through a tunnel (I followed the tutorial).
Irrelevant how the boundary conditions are selected, they are at a enouch distance to not have affect the flow regime through the tunnel. In this case boundary conditions are (Normal depth upstream and downstream, Mixed flow analysis).
The longitudinal profile shows that the water passes through the barrier. I do not know why? (Picture No.1)
Down you can see the cross section near the start of tunnel
I THINK SOMETING IS MISSING IN THE INPUT DATA!

[igorce]

I agree with Keith M about point one, about unrealistic WSE downstream of the bridge (honestly that part downstream analyzes are not important), but I’m still in doubt about the correct analysis (mixed or supercritical) near the bridge.
Jake G, about your comment in part “b”, you say: Supercritical flow would only be expected in limited situations, such as a concrete channel or steep bedrock channel.
Please read this additional information:
From first Cross section(XS) upstream from the bridge, to third XS downstream from bridge are just how you say: REGULATED CONCRETE CHANEL whit 1% slope (that make me supercritical flow and freoud number more than 1.0).
Now the doubt is:
1. If i make a mixed flow analysis near the bridge, i cant belive on results, becouse i have WSE more than orientation results with equation Q=A*V, but if i make a Supercritical flow analysis than i think i have correct results.
2. Can HEC-RAS combine, mixed flow before regulation(natural zone),and Supercrtical flow in regulation zone (before, in, and after the bridge)?_Honestly i dont belive in this!

PS.
In this case the bridge is part of highway and here i have one more important question:
Did i must make solution for subcritical flow or i can use the slope of the natural terrain?

Thank you for answers and i really appreciate this!

[igorce]

We have misunderstanding my friend.
In this case, i have a lot off changed points, i can’t XY coordinates one by one change in Civil 3D(to much time lost).
I’m try to find answer how to input station and elevation with original coordinates from Hec-Ras to Civil3d. After that, i will recreate model and make geo. file.
About your question, completly i agree. We will wait some who know to tell us.
But that is different problem than my.

[igorce]

I’m still waiting for answers or comments.

Is it possible no one can answer the questions?
Is there a possibility to set boundary conditions in each section?
How can we solve the problem of illogical flow?

[igorce]

I was get warnings, not errors. In continue i share you print screen !
Thanks in advance if you can halp me

[igorce]

Thanks for the reply to my message:
If you look at the new situation, when i expand the channel from 8 to 10m, then there is no problem, even though the slope is retained, and get logical results. I am now confused what is really going on here!?
I’ve seen many projects and designers that use this software to calculate the mixed flow regime through the spillway,with steep slopes, such as slope of 50%.
In my case this is spillway.
how do you think i can use boundary layer theory?
can a few sentences to give me suggestions and any literature that you use.
It would be good to compare the theories used in my country.
Which software to use for this type of problems?

greeting!

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