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cardno

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  1. This is a known 'feature'. The TUFLOW manual states "Slightly different results (mostly fractions of a mm) will occur between w32 and w64 for the same model" Given the small differences, it shouldn't really matter which version of TUFLOW you use. If you are using 64-bit computers at work, I would use the 64-bit version of TUFLOW.
  2. cardno

    SMS ALL.sup

    Notwithstanding this would be a good new feature, note that the SUP file is a text file, so you can edit it or create a new one, and include the _Times.dat file in the list of files to be loaded.
  3. Paul You could import the peak water level grid for both cases into MapInfo (Vertical Mapper), and use Vertical Mapper to calculate the difference between the two grids.
  4. Hi Tom You are correct - TUFLOW used to show a line in the TLF file like: Run Complete ... Steps: 3601 Errors 0 Av.Wet/Step: 507 Simulation took 0.02 hrs at 28116 wet cells/sec This was stopped around version 2005 I think. Our experience with 2.4-3.0 GHz computers is that TUFLOW runs at about 150,000 to 200,000 wet cell timesteps per second. Other users might be able to comment on the speeds they get with different computers. Bill - maybe you could put this "average speed" result back into the TLF file so users could compare computer speeds?
  5. The TUFLOW log file keeps track of who is using the dongle. Refer to Section 7.1.3.2 of the Manual for details on how to set this up.
  6. cardno

    QT Boundaries

    If TUFLOW is saying that Qo is 0, then no flow is leaving the model. I agree that the flow should be gradually introduced, rather than immediately added as a large lump. Some other suggestions are: 1. Have you checked the boundary inflow in 2d_2d_bc_tables_check.csv? 2. The large instability at the first timestep suggests a problem with the initial conditions. Is the IWL set correctly? The extent of inundation shown in the SMS image looks unusual. 3. Have you checked the Z levels in the model at the boundaries, to make sure there are no -9999 metre values? Hope this helps.
  7. Please see http://www.tuflow.com/forum/index.php?showtopic=639
  8. If it's not working from UltraEdit, it will not work from a batch file either. Are you using the latest Dongle Drivers?
  9. I would suggest varying the "d" value in the 2d_bc layer connecting the 2D domains. Start with the minimum value (30 metres in this case), then try some larger values, depending on how you have digitised the boundary.
  10. The problem may be due to a change in the defaults used by TUFLOW since 2004, especially regarding the invert levels in the 1D domain (refer to the TUFLOW Manual, page B-16 under "Apply All Inverts"). If you are running the 2008 version of TUFLOW, you may want to turn on the "Defaults == PRE 2006-06" command in your TCF file. Cheers
  11. Hi Paul You've probably already seen this, but I would also refer you to QUDM 8.03.4 regarding Coincident Flooding.
  12. I have modelled the weir as a 1D link, and this has resolved the stability issue around the weir (and gives the expected water level upstream of the weir). Thanks all for your suggestions. However I would still like to understand the reasons why the 2D weir gave such unstable results. Cheers
  13. Thanks for the responses. To provide some more info to the questions raised: 1. The weir is level along its full width, and is sharp crested. 2. The weir is modelled using a THICK z-line. (Perhaps a THIN line would be better?) 3. I tried using the double precision TUFLOW, but it did not make the results more stable. 4. The boundary of the model is about 1800 metres downstream of the weir. I will try modelling the weir as a 1D link to see if that improves the stability of the results.
  14. Hi all I am modelling flood flows in a tidal canal. The canal is approximately 100 metres wide with a Manning's n of 0.025, and an invert level of -3.5mAHD. The model uses a 6 metre grid and 3 second timestep. A 48 metre wide weir is located across the canal, at a level of 0.6mAHD. The 100 year flood level upstream of the weir is 2.0mAHD. Everything is modelled in the 2D domain. The model runs well and has a low mass balance error of -0.1%, however the flows and water levels in the vicinity of the weir are quite "unstable" when the flood flow starts to increase, particularly just downstream of the weir. Because of the very high conveyance provided by the canal, a small change in water level means a very large change in flow. Is there a way to make the model results more stable around the weir? I tried halving the timestep, but that did not help. Would the weir be better modelled in 1D? Thanks
  15. What slope have you used in the model for your HQ boundary? Our experience has been that very low slopes produce the effect you are describing. I suggest you use a steeper slope, to get a stable boundary.
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