Hec-Ras Unstready Flow Model Dam Failure Analysis
Hec-Ras Unstready Flow Model Dam Failure Analysis
(OP)
I am using Hec-Ras for a Dam Failure analysis using an unsteady flow hydrograph.
The dam has a constant 170 cfs flow through low flow outlets.
What is the best way to model this constant flow through the dam?
The dam has a constant 170 cfs flow through low flow outlets.
What is the best way to model this constant flow through the dam?





RE: Hec-Ras Unstready Flow Model Dam Failure Analysis
RE: Hec-Ras Unstready Flow Model Dam Failure Analysis
If you're entering the breach hydrograph directly as an upstream boundary condition (which it sounds like you are), then enter 170 cfs as a minimum flow in the breach hydrograph boundary condition dialog box(there should be no inline structure representing the breached dam in the model). If you're modeling the breach directly in RAS using an inline structure, then build a constant upstream inflow hydrograph boundary condition of 170 cfs througout the simulation, and enter 170 cfs as a pilot flow in the inline structure dialog box.
In either case, the first ordinate of the upstream inflow boundary hydrograph, the inline structure pilot flow, and the downstream reach initial flow all have to be equal.
RE: Hec-Ras Unstready Flow Model Dam Failure Analysis
We are modeling the breach directly in RAS using an inline structure. I looked but I did not see where it gives an option to enter in a pilot flow in the inline structure dialog box.
Thanks for the post.
RE: Hec-Ras Unstready Flow Model Dam Failure Analysis
RE: Hec-Ras Unstready Flow Model Dam Failure Analysis
Thank you very much for the help.