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Viewing 15 posts - 286 through 300 (of 672 total)
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  • in reply to: HEC RAS 1D-2D #11379
    cameron
    Participant

    This basically means your model is going unstable or it means your 1D htab parameters need to be adjusted.

    You may need to lower your timestep or turn on the 1D/2D iteration option.

    cameron
    Participant

    What do you mean from tiles? Do you mean raster results or are you talking about the tiles that can be in a web map?

    You would need to set up the ras map file to save out the rasters you want and have the floodplain mapping button checked when you run the program for it automatically create raster outputs. This can be done with some scripting.

    in reply to: RAS 2D Terrain Accuracy #11389
    cameron
    Participant

    The second terrain is what you will want to use. Terrain is not flat like you have for the first terrain and will for mess up the mapping results. Each cell face is a cross-section and applies the n value the same way the 1D models do.

    You are over thinking it.

    in reply to: Advanced Time Step Control-Precipitation #11368
    cameron
    Participant

    Residence time should not be used for rainfall models. Yes you will get models that are stable, but they will be very very slow. This is also true for very steep areas.

    Grid cells that only a small volume of water get into will cause the residence time timestep to need to be very small.

    I have found that you need to take care in which values you specify for the min and max values or else the model either does not run faster or you get bad results.

    in reply to: geometry error 5.0.4 #11371
    cameron
    Participant

    was the software installed correctly? do you have the exe on your machine?

    in reply to: Hec-Ras 2D results doesnt appear #11266
    cameron
    Participant

    is the 1D model connected to the 2D model?

    in reply to: flow hydrograph #11304
    cameron
    Participant

    Well the discharge in the second figure is quite a bit higher than the first figure. Hard to know how far apart they are from each other.

    Does the second one have a bunch of discharge from somewhere to make it have a constant flow?

    in reply to: Model Efficiency – 2D Culvert at Issue #11306
    cameron
    Participant

    does the problem grid cell get a lot of depth of water or is only a small corner of it getting wet? If only a small corner is getting wet, you may need to adjust it by stretching it out (moving adjacent cells around) to allow more volume in the problem grid cell.

    Not sure what the overall cell size of the model is, but a 24 hour run with a 2 second time step that takes an hour to run is not unheard of.

    in reply to: Flat Water Surface Elevation #10117
    cameron
    Participant

    what is your downstream boundary?

    in reply to: I can’t see the cross sections #11297
    cameron
    Participant

    Did you set up a spacial coordinate system first? My guess is the line you drew is very small and does not match real world coordinates.

    in reply to: HEC-RAS 5.0.4 Beta #11290
    cameron
    Participant

    This version should be out this month or next month.

    in reply to: new to HEC-RAS #11286
    cameron
    Participant

    You could just use QGIS to project the data. QGIS is free.

    cameron
    Participant

    Do you have the 1D/2D iteration option turned on? Try using the weir equation instead of the 2D equation for the weirs as this sometimes hides issues.

    in reply to: Output Sa/2D connection #11260
    cameron
    Participant

    Do you mean the hydrograph and stage for the structure? You can find it in the plot stage hydrograph button and selecting storage area connection as the type. You could also look in the dss file.

    in reply to: 2D Mesh only: Output flooded areas not connected #11254
    cameron
    Participant

    It also has to do with the fact that you removed the decimals from the terrain.

Viewing 15 posts - 286 through 300 (of 672 total)