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Viewing 15 posts - 271 through 285 (of 672 total)
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  • in reply to: Breach weir in a 2D mesh #11512
    cameron
    Participant

    Depending on your cell size, you may not have to erase anything. If the cells that are along the 2D connection extend far enough away from the top of embankment (beyond the toe) and have elevations which you want to breach to, then you don’t need to do anything. If this is not the case, you would have to make the grid cells along the dam larger.

    If you do want to remove the dam/embankments what I do is buffer the centerline of the embankment a width so that it covers the embankment, then generate a ton of vertices along the buffered line, convert to points, extract elevations, create TIN from points and buffered line, convert to raster, and mosaic to original terrain.

    I like the TIN option as it keeps it smooth, if you go from points to raster it can cause a rounding effect.

    in reply to: Breach weir in a 2D mesh #11510
    cameron
    Participant

    I agree with Scott about the issue. You need to either adjust the breach elevation or modify the terrain.

    in reply to: 1d model – flow direction? #11506
    cameron
    Participant

    You need to reverse the stationing of your stream centerline. station 0 is supposed to be the start of the model.

    in reply to: Plot data for Weirs in a 2Dmesh #11501
    cameron
    Participant

    They would have to be area connections

    in reply to: Dam break analysis – too much slow time computation #11499
    cameron
    Participant

    with 2 million elements at 5 meters (hope it is meters) the model will take a very long time to run.

    Did you check to see how long you actually need to run it? For instance, check when the peak occurs at the downstream end and maybe you can trim the model run time. The other comments provided should help as well. Another thing to think about is how deep the water is. If the max depth is really deep, you can probably get away with larger cells and get the same answer.

    It is common for very large models with small grid cells to take a long time to run.

    in reply to: Dam break analysis – too much slow time computation #11495
    cameron
    Participant

    Cannot read anything as it is blurry. 2D models can take a lot longer than 1D models. It all depends on time step, cell size, and number of elements.

    Dam breaches have highly dynamic fast moving flow so in general you will need a smaller time step than other applications.

    in reply to: Lateral flows in a 2D mesh #11491
    cameron
    Participant

    You can add internal boundary conditions into the 2D mesh in 5.0.5 so yes you can add in a lateral flow.

    in reply to: Issue in water surface profile of river #11490
    cameron
    Participant

    The profile is based on the invert of the cross-sections which picks the lowest value between your bank stations. It appears that your bank stations may not be set correctly.

    in reply to: 1/2 D Modeling help #11486
    cameron
    Participant

    Break it up into smaller pieces. It If you have a single lateral structure, editing the weir data will take forever as it will take a long time to load data.

    in reply to: Hydrograph output interval less than 1MIN #11428
    cameron
    Participant

    You can set it so it writes using the computation interval and what time you would like it to. the entire run or specific time frame. It is in the output options in the plan menu.

    in reply to: Rasmapper window not opening in HEC-RAS 5.0.4 #11411
    cameron
    Participant

    do you have a 32-bit system or 64-bit? the new mapper only works in 64-bit.

    in reply to: IC Points in Geometric Data 5.0.4 #11404
    cameron
    Participant

    That’s because it was more of a bug fix release than a new feature release, but they had to include some of the new stuff they did.

    in reply to: HEC RAS 1D-2D #11384
    cameron
    Participant

    set the max 1D/2D iterations to 20.

    What is the weir coefficient you are using for the lateral structure? Did you try setting it to use 2D equation instead of weir?

    This all only applies if the issues are near the 1D/2D connection.

    cameron
    Participant

    I would reach out to HEC to see if there is a way to automate the web map server tiles.

    in reply to: HEC RAS 1D-2D #11382
    cameron
    Participant

    what is your time step?

Viewing 15 posts - 271 through 285 (of 672 total)