Forum Replies Created
-
AuthorPosts
-
cameronParticipant
The arrival time is at what time the cell gets to a depth you specify.
The duration is how long it is at a depth you specify.
The recession is how long until it drops below a certain depth you specify.cameronParticipantDoes your terrain cover the extent of the cross-sections? This occurs in GeoRAS when the cross-sections extend beyond the terrain it is trying to extract elevations from.
July 2, 2017 at 5:56 am in reply to: Breakline and Cell Spacign Techniques at Roads/Linear Strutures in 2D #10683cameronParticipantwhat is your time step and are you using the full momentum equation? Do you have any water surface errors as the model is running?
July 1, 2017 at 12:48 am in reply to: Breakline and Cell Spacign Techniques at Roads/Linear Strutures in 2D #10688cameronParticipantWhat does your terrain look like. where the breaklines are? Does the terrain pick up the road?
cameronParticipantDid you adjust the Htab parameters? Are there any structures in the model? Do the hydrographs at any of the structures look funny? Have you tested different timesteps? Do you get any errors when running in unsteady?
cameronParticipantYou could have opened it in QGIS (which is free) and converted the depth grid to a polygon.
cameronParticipantWe use some custom scripts to create cell sizes that vary. You could also use SMS which has added the option to generate RAS meshes.
June 3, 2017 at 5:21 pm in reply to: Can you put a stop at end of hec-ras channel to force all flow over the lateral weir #10617cameronParticipantWhat are you using for your weir coefficient on the lateral structure?
cameronParticipantI have done models with over 2,000,000 elements, but I have 64gb of ram.
There is no way to nest models so you would have to use unstructured meshes or break up the model into multiple 2D meshes connected by 2D connectors.
cameronParticipantSteady state does not account for attenuation as it assumes an infinite amount of water.
May 18, 2017 at 6:24 pm in reply to: Error loading data for geometry schematic plot. Overflow #10587cameronParticipantWhat is in the geometry?
Did you try to import in the geometry to a new geometry file?
cameronParticipantin the Options|Output Options|HDF5 Write Parameters window you can check a box for it to write velocity data at the face node locations.
The data will be saved in the hdf file for the plan (*.p01.hdf).
May 18, 2017 at 6:16 pm in reply to: 1D/2D Lateral Structure Volume Accounting Errors (solution) #10596cameronParticipantI have seen this before. Did you have the 1D/2D Options iterations turned on (found in the options and tolerances window)? What was the lateral structure weir coefficient set to?
This should force the flow over the lateral structure to fall within some value that you specified and should have resolved the 25K cfs issue. I have seen issues where the wse in the channel is a couple feet higher than the overbank due to not enough flow being able to get out over the lateral structure as the weir coefficient was to small.
Switching to the 2D equations is also another fix for this issue.
cameronParticipantThere are some general guidance for cross-section spacing such as Samuel’s Equation or 5 times the channel width.
But as Keith stated, it is reach/model dependent.
cameronParticipantdid you try and delete the hdf files for that plan/geometry and then rerunning it?
-
AuthorPosts