This will be the last 1D steady flow lecture we post for a while because the second half of the class needs to go out for editing. We'll start posting sediment transport classes in the interim. We are also working on 2D and 1D unsteady, but they will be a while.
Very good discussion on the energy gradeline at a drop in the water surface profile. That just recently came up in one of my model reviews, and this helps me give an informed response.
Just a quick question, if we have a tailing facility (non-Newtonian fluid) and a water dam (Newtonian fluid), then how these two can be modelled as in "Unsteady Flow Data", just one flow regime can be defined for the whole system, i.e. Newtonian or Non-Newtonian flow regime. Please correct me if I am wrong and if there is any solution to model these combination of flow regimes. Thanks
This may be the most common question we get about 2D and I really need to do a video on it. In the standard fixed-bed NN tool, no, you only get one global Cv. But you can "hack" this by setting up a simple "mobile bed" sediment model (we even added simplifying tools like "concentration only" mode and a "deposition limiter" that will use the sediment engine to use the AD equation to route your debris flow into clear water...mix with the clear water, update the concentration, and feedback on the NN parameters. I really need to do a video on this...but i'm not sure when I'll get to it.
@@stanfordgibson Thanks a lot! will be very useful for us, students. Could you please tell me on which webpage will it be published? I will be tracking it 🙏
Hello, I have a problem I am trying dam breach analys and I had an hdf error. It gives “Error in the time window Hdf error trying to close hdf output file hdf5 diag: Error detected in hdf5”
Many thanks for sharing such a wonderfull class. I love to hear about computational open channel hydraulics especially from a hydraulics lover like Dr Gibson.
Answering two previous questions in case the next viewer benefits. The auto-fixing option "Try Fix" can be found by right-clicking 2D Flow Areas under editing mode.
Hello, Thanks for the video. I'd like to know the HEC-RAS limitations. When we simulate sediment transport, usually we have rivers with steep slopes ( greather than 4%). Which is the max bed slope of the channel that HEC-RAS could handle? could you help me with this question please?
just wanted to ask do we have to import subbasins which were generated in hechms, in hecras and then do we need to define boundary condition for each subbasin separately or do we have to create a single 2d flow area perimeter for all the subbasins as whole, for 2D flood modeling? as we'll be using outputs from hechms which were generated for each subbasin
Is there a way to model infiltration losses of accumulated flow from a precipitation event? For example, having large runoff produced in high impervious areas be infiltrated as it flows into sandy soils?
How about 2D Computational Options? I was interested to the Layer Thickness parameters. How to assign Initial, Min and Max values? The Initial (or Min) value is the same of the Min Thickness that I have to assign in the Bed Mixing Options? Waiting for your support. Thanks a lot and compliments for sharing!
I got a question. Are the precipitation data you selected when reading in DSS data gradually changing over time, the same value throughout the entire plane, or different precipitation values at different points? I look forward to your answer or anyone else’s answer.
Great tutorial. Thank you Gary! Is there any tutorial link or documentation on using HEC MetVue to create a gridded rainfall input DSS file from raster data?
When we give the upstream hydrograph data, what is the time duration that we give for the hydrograph. Is it the same as breach formation time as calculated by different methods.
Thank you very much for another excellent lesson. I never gave this topic much importance because I never needed to. But when it comes time to use HEC-RAS to make these types of predictions, I come to watch your videos, because you are my source of knowledge.
Hello, according to the reference manual, in the SWE, the cell velocity is approximated from the face normal velocities. The cell center velocity terms that stem from the weighted least squares method are provided. However, it is not clear how to calculate wk (weight of face k) found in the terms. Inspecting Perot's (2000) paper hasn't helped.
