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Tina O'Connell

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Everything posted by Tina O'Connell

  1. Hi Mick, Thanks for that. I downloaded the tools earlier today so I'll install them tonight and give the new feature a go. CHeers Tina
  2. Ben2 Wow! If only I'd read the manual from cover to cover! That's a very useful tool. I've been writing a DXF from 12d and using that DXF twice. Once with Universal Translator to give me a MI table of polylines. Once with a crude macro I wrote for Ultraedit that converts the DXF file into a CSV file of all the points. Then I have to open the CSV file in MI and save it as a MI table. Glad this came up in the forum. T
  3. Hi, Could the "Label zpt or zln layer with elevation" tool's capability be expanded to include labeling of 2d_ztin layers please? Tina
  4. Hello All, I am using Create TIN Zpts WRITE TIN == to very effectively add lineal infrastructure to my developed case model. I have 4 separate commands for 4 separate TINs. I know all 4 are being processed because I get the same elevation check files and results if I swap the order of them around. However, only the first TIN is written to the 2d_sh_obj_check.mif layer. Is this on purpose or can the program be altered to write all TINs to the same 2d check file? Tina
  5. Very handy to find this remedy on the Forum at 8.30PM on a Sunday night. I kind of figured it was telling me I needed channels but I was going to add one channel for each node, something I knew I'd never done in the past (because I'd always previously had a 1D channel network) and something which was going to be onerous for my 60 inflows. Cheers Tina
  6. Hi Bill, Yes it seems I am alone in this world thinking that 30mm is an unacceptable difference. I will move on. Thanks Tina
  7. Maria, The AustRoads publication "Waterway design - a guide to the hydraulic design of bridges, culverts and floodways" has a section "Effect of Dual Bridges" which you may want to read if you haven't already. But the duality (or in your case triplicate nature) is dependent on the embankment of each interfering with contraction and expansion of flow rather than on interacting pier turbulence losses. I think (and I stress it is only my thoughts) that you should apply the same additional form losses at each pier set at each bridge. And provided you have sufficient grid resolution, TUFLOW will handle the embankment interference in expansion and contraction in the 2D domain. Tina
  8. HMax in the 100 year event is 30mm lower. They have only pier resistance in the model. No weir flow or higher roughness at the relevant 2D cells. What would you decipher "Constant 0.2 m^2/s Eddy Viscosity - Velocity based" (as taken from the attached print screen of the MIKE 21 simulation file) to mean? I've included extracts from the HD manual as an attachment. The more I think about it, the "Velocity based" part would only be for Smagorinsky Formulation, the pre-processor is just not fine-tuned to "grey it out" for Constant Formulation. Eddy_Viscosity_in_MIKE_21.doc
  9. Rhys, Thanks for your reply. I have bridge decks way above the 100 year flood levels and a grid size small in comparison to the overall bridge length (5m for a 180m bridge) so wall and roof resistance are not coming into play and cell width is not reduced. All the FCs are attempting to model is the additional form loss due to pier resistance. MIKE 21 does indeed apply pier resistance differently from TUFLOW in that you specify pier size, shape, invert and obvert at a specific location and the program internally calculates the turbulence losses. As far as I can determine, it is impossible to plot the magnitude of these losses or the coefficient of loss calculated within the MIKEZero or MIKEToolBox framework, so the only reference to whether TUFLOW is operating similarly through the structures is in replicating current speeds and water levels. Having said that, it is difficult to replicate these when the downstream tailwater level is not consistent. I will persevere in changing eddy viscosity and its application to raise the downstream tailwater levels. Regards Tina
  10. The manual does not mention that a fourth option is available for calculating the bed resistance at cell sides. That is "MAXIMUM n" which seems to take the highest of the two adjoining ZC values. So Bed Resistance Cell Sides == [ AVERAGE M | AVERAGE n | {INTERROGATE} ] should read Bed Resistance Cell Sides == [ AVERAGE M | AVERAGE n | MAXIMUM n | {INTERROGATE} ]
  11. Hello, I have a purely 2D MIKE 21 HD model for which I am trying to replicate resulting levels for a range of flood probabilities. It has an upstream QT boundary, downstream HT boundary, and starts from a constant IWL on a regular 5m grid centring on two existing bridge crossings. The ZCs were created from the MIKE 21 bathymetry file. The ZUVH points were interpolated. The Materials file was produced from the MIKE 21 resistance grid. There is an area downstream of the bridges where the TUFLOW model consistently (for viscosity formulations constant, smagorinsky and a combination of both, for a range of viscosities from 0.2 to 1) shows lower levels in the 100 year event (I haven't progressed to smaller events so can't comment there) than the MIKE 21 model. Froude numbers in this area are approaching 1. Could someone give some discussion on which TUFLOW commands I should be considering changing to more closely replicate MIKE 21 levels. Here are some of those I am considering /have considered: Cell Wet/Dry Depth == 0.02 MIKE21 has drying depth 0.02/flooding depth 0.03, levels downstream of bridges are insensitive to changes in this parameters from 0.02 to 0.03 BC Zero Flow == OFF First Sweep Direction == POSITIVE Bed Resistance Cell Sides == INTERROGATE Switching to Average M/n makes the TUFLOW results in this area even lower Wetting and Drying == ON NO SIDE CHECKS Supercritical == ON Switching to OFF made minimal difference downstream, dropped levels slightly upstream (2mm) due to changes at bridge abutments Froude Check == 1. Free Overfall == ON Global Weir Factor == 1. Shallow Depth Weir Factor Multiplier == 1. Shallow Depth Weir Factor Cut Off Depth (m) == 0.0001 !Latitude == -27.41 In MIKE 21 files, Coriolis forcing is not checked, TUFLOW results not sensitive to switching it on Water Level Checks == ON Oblique Boundary Method == ON Boundary Treatment == METHOD A Line Cell Selection == METHOD D Inside Region == METHOD B Density of Air == 1.25 Density of Water == 1025. Wind/Wave Shallow Depths == 0.2, 1. Thanks Tina@dks
  12. Bill, I attempted to use the QTA boundary on my 60 GIS points with the a flag set to 30.03 (approx. 30 degrees). The run stops at processing of the first boundary with the following error: ERROR 2041 - Too many QTA tables. I have tried only one of the points as a QTA with the rest reverted back to QT. Again same error. I have tried reducing the number of points in the timeseries for the one QTA point. Again the same error. To what is the error referring? Thanks Tina
  13. Hi, I recommend the manual get updated at page A-12 of TUFLOW Manual.2008-08.doc from: t eddy viscosity coefficient output (ā€œeā€ prior to Build 2002-10-AH) to: t Smagorinsky eddy viscosity coefficient output (ā€œeā€ prior to Build 2002-10-AH) to avoid the confusion of the t.dat containing a constant 0.0 value (geographically and spatially) when Viscosity Formulation == CONSTANT is chosen. Tina@dks
  14. Hi, I have the following code in my tcf file: Viscosity Formulation == CONSTANT Viscosity Coefficients == 0.8 The tlf for Build: 2008-08-AA-iSP and for Build: 2008-08-AB-iSP mirrors with: !______________________________________________________________________ ! EDDY VISCOSITY COMMANDS Viscosity Formulation == CONSTANT ! Options [ {CONSTANT} | SMAGORINSKY ] Viscosity Approach == METHOD A Viscosity Coefficients == 0.8, 0. ! Variable, Constant components Could someone please confirm that this is still applying a constant 0.8 coefficient. Certainly changes to the 0.8 value result in changes to model results, hinting that it is being applied correctly. Perhaps the coding for the tlf file should be changed to include "WARNING: expected two coefficients" when CONSTANT formulation is selected. Thanks
  15. Could someone please give me an example of this type of bridge shapefile. Is it supposed to be one polygon representing the deck of the bridge, or a series of polygons some of which are shaped as per the piers and inbetween the bridge deck? Also, does the first layer have to be to the underside or soffit of the deck, or can layer 1 be to the underside of the headstocks? ie does TUFLOW put a lid on layer 1 and increase the cell resistance even if layer 2 percentage blockage is not set to 100%? Thanks tina@dks
  16. Bill, Thanks for your reply. I am in fact using 60 QT points in cells that are active and along the code boundary. Adjacent the first and last cells are land (or inactive) cells. So in theory, the flow will cross only the one boundary, that into the model. The reason for this is to replicate a MIKE 21 model which applies a varying QT boundary (which I suspect was created from the output of a much larger model). Certainly a PO line along the active side of these cells produces a cumulative flow hydrograph equivalent to that shown in the MIKE 21 report. Greg suggested to me yesterday to switch to 60 ST point boundaries (as I am having trouble replicating MIKE21 levels in this region) but I have not had a chance to check this makes a difference. Tina@dks
  17. Further to Bill's comment about QT boundaries snapping to the code polygon, is there a default direction if the QT boundary is digitised as a point? ie Will it always be applied as a flow across ZU no matter where in the cell the point is digitised? Do you need to invoke the A flag and digitise a line if you want it applied in any other direction?
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