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cameronParticipant
instantaneous. It will provide the velocities at the time it writes the output. It is the same as what you would see in Mapper where you go through the mapping output interval.
The values that get listed are the Vx and Vy in the HDF file when you select this option.
September 12, 2019 at 9:50 pm in reply to: Best way to update channel geometry with revised elevation data #12517cameronParticipantOpen the detailed terrain in Mapper
Create a new geometry called LiDAR and use Mapper to extract the LiDAR for each cross-section
Create a copy of the LiDAR geometry called combined and use the graphical editor to merge the channel data from the original model into the LiDAR.cameronParticipantwhat is your cell size? What is the minimum flow? Are you using full momentum or diffusion wave for the solver?
September 11, 2019 at 6:16 pm in reply to: Flows at d/s of the lateral structure and leaving it, after optimization does not add up to the flow in the u/s #12507cameronParticipantIf you look at the 7097 and 648 values they add up to the total amount upstream of the lateral structure. The lateral structures span at least two cross-sections (could be more) so the total split flow would not be seen until after the lateral structure.
September 10, 2019 at 6:04 pm in reply to: Flows at d/s of the lateral structure and leaving it, after optimization does not add up to the flow in the u/s #12505cameronParticipantFirst make sure your weir coefficient makes sense for a lateral structure (see link below) as 2.5 is out of range from what HEC recommends.
http://hecrasmodel.blogspot.com/2013/12/lateral-structure-coefficients.html
What is the discharge values downstream of the lateral weir in the cross-sections for both the main channel and the side channel? Do they match the table you presented? Have you done a simple hand calculation to make sure the values make sense from the model (CLH^(3/2)?
September 9, 2019 at 11:54 pm in reply to: Flows at d/s of the lateral structure and leaving it, after optimization does not add up to the flow in the u/s #12503cameronParticipantwhat is your weir coefficient? Does it make sense? Are you getting convergence when you turn on flow optimization or is it hitting the max iterations?
cameronParticipantare you modeling a bridge and a culvert at the same structure?? You cannot have both a bridge with piers and culvert at the same structure unless you do multiple openings and split the structure into multiple.
If it is really just one opening then you are modeling it wrong. You would adjust the low chord to represent the opening and add piers, no culvert.
September 9, 2019 at 5:39 pm in reply to: Floodway analysis using HEC-RAD 2D for FEMA Project #12497cameronParticipantyou currently cannot do a floodway in 2D. What you can do is create a 1D model that is calibrated to the 2D and create the floodway in the calibrated model. I have also done 1D/2D models where the floodway is only in the 1D section.
cameronParticipantYou can update the banklines in Mapper to match the bank points which should match what you set in the cross-section editor.
To do this go to edit mode and right click on the banklines.
cameronParticipantIs it switching from energy to momentum?
cameronParticipantThe FMA Modeling and Mapping Committee has just been doing this, but in the cloud and for a range of software not just HEC-RAS. The basic idea was we setup a cloud that people could remote into and test different types of software for three different datasets along with a few different machine configurations. The results of the findings are going to be presented at the FMA conference in San Diego in September.
We started working on this idea last year and was a big effort by those on the committee and I hope everyone at the conference enjoys panels.
Side note – none of your links worked
cameronParticipantThis happens all the time when you open up the channel. The velocities most likely reduced which causes the wse to increase.
cameronParticipantThere is a fix command in Mapper, but it is hit or miss as it just splits the cells with >8 sides in half.
August 5, 2019 at 5:18 pm in reply to: easiest way to extract courant number from results? 2D model #12429cameronParticipantThere is an result output for Courant Number in Mapper which would be the easiest way.
June 30, 2019 at 7:37 pm in reply to: Flow Optimization Failure and convergence for similar boundary conditions #12336cameronParticipantThe model starts trying to optimize with the initial split flow that you specify. If it doesn’t optimize with the first iteration, it tries different values. If you turn on the log file for the lateral structures, you will be able to see which values it is picking and what it is trying to converge to.
The reason why it works for one and not the next is how it is picking the next guess.
Based on your profile, is looks like the issue is around station 18000-19000 where the lateral structure is just barley overtops. The weir coefficient would probably be pretty low for this type of scenario to get it to be stable.
The things to fix it are as you have done, adjust weir coefficients, tolerances, or adjust the initial split flow values. You could also adjust the weir elevation slightly to see if it helps.
You may have to end up having different geometries where the only difference is the weir coefficient.
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