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Bill Syme

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  1. Hello all We are pleased to announce that we are transitioning to a new website (same www.tuflow.com address) over the next day or so which will change the URL to the forum. Whilst old URLs will be redirected, should you have any shortcuts to this forum it is recommended to change from the old link (https://www.tuflow.com/forum/) to the new link (https://forum.tuflow.com/) to maximise access speeds. The TUFLOW Wikis will not be affected by the changeover. Please note that during the transition the website and the forum will experience outages. Once the transition has completed we will make an announcement on this channel. Apologies for any inconvenience during the transition and we look forward to showing you our brand new website. Should you have any queries or experience any problems after the transition, please don't hesitate to contact support@tuflow.com. Best regards The TUFLOW Team
  2. The 2019 TUFLOW Release Australian Workshops start in a few weeks, and this year’s release is a big one so if you're interested signup soon as there are limited places remaining. The dates of the courses are provided further below and on our training page. To register download the flyer or email training@tuflow.com. The 2019 release is another game changer off the back of last year’s highly successful TUFLOW HPC engine release. This year there are major enhancements to the HPC engine and other exciting developments including: · Quad-tree mesh resolution refinement · Sub-Grid Sampling (SGS) that utilises the finer detail of the underlying DEMs/TINs in the hydraulic calculations · A new sub-grid turbulence scheme that has minimal cell size dependency · Non-Newtonian flow for modelling slurry and tailings dam failures · The TUFLOW Viewer GIS tools · Numerous new minor features Quad-tree refinement offers substantial benefits allowing you to very easily have finer cells where the hydraulics and topography require those extra levels of resolution (or coarser cells in areas that don’t need high resolution). Sub-Grid-Sampling (SGS) in combination with the new sub-grid turbulence enhancements is proving to be a game changer for fixed grid modelling. For whole-of-catchment models (e.g. direct rainfall models), the response times are quicker and water retention substantially less, especially where the DEM resolution is much finer than the cell size. For deep sided smooth channels, for example a concrete lined trapezoidal channel, that are not mesh aligned the flow patterns no longer have “saw-tooth” effects and now closely obey Manning’s formula. Sensitivity of results to mesh size is greatly reduced and effects due to rotation of the grid almost eliminated. This is far-reaching in that TUFLOW HPC is now able to produce the same quality of results as a well-designed, high resolution, flexible mesh construction, even if using a coarse cell size. The release workshops will provide detail on the new features and the hands-on computer-based training the day following allows you to apply the new features to models. Due to over-subscription of our introductory training courses in the middle of this year, we’re also offering another round of introductory courses the week prior to the release workshop/training. 2019 Release Workshop Schedule and Details Location Introductory Training (computer based) 2019 Release Workshop 2019 Release Training (computer based) Brisbane 15 - 16 October 22 October 23 October Sydney 5 - 6 November 12 November 13 November Melbourne 26 - 27 November 3 December 4 December Introductory Training Two-day computer-based training that is aimed at new TUFLOW modellers. The course includes TUFLOW theory, followed by practical model creation and review of results. 2019 Release Workshop Aimed at all TUFLOW users from modellers to managers. The day will provide detail and discussion of the new features included in the 2019 release. 2019 Release Training Computer-based training is tailored towards existing modellers who want to learn, and have a hands-on experience, using the 2019 release features. People attending this session are advised to also register for the release workshop the day before. Looking forward to seeing you there! Best Regards Bill Syme
  3. Hi This was a rarely used (legacy) feature that allowed the user to place SX cells in one location, but use cell depths slightly offset from the SX cell to distribute the 1D flow across the SX cells. It was occasionally used when SX cells were entered by row,col rather than a GIS object - yep, that's how the very very early TUFLOW models were created! - and, for example, a proposed road embankment levels might change slightly and affect the SX cell level. By using the offset, the elevations of cells not being modified by the embankment could be used to distribute the SX flow and thereby have consistency between what-if scenarios. These days with much smaller cell sizes and all the advantages of GIS, this feature is not used or recommended. If using, double check what happens to the SX cells and their elevations via the check layers and make sure the results look sensible. Cheers Bill
  4. We are pleased to announce that the TUFLOW Release 2017-09 is now available. To download the release and view the release notes please use the links further below. The 2017-09 release includes some major new features and range of enhancements. The most significant of these are: New HPC solver (major rework of TUFLOW GPU). Changes include: Ability to run on CPU or GPU. New cell schematisation (to be consistent with Classic and use of cell side elevations and sampling). Enhanced 1st order and new 2nd order spatial schemes. Full 1D/2D linking using the same SX and HX methods as TUFLOW Classic, giving access to all 1D functionality. Significantly better scaling when running one simulation over multiple GPU devices. Inclusion of more TUFLOW Classic functionality (e.g. layered flow constrictions, SA Trigger boundaries, and additional outputs). Previous “GPU” solver available for legacy models. Improved stability and stability options for SX connections to large 1D structures for Classic and HPC. New software based licencing options. Numerous enhancements and new functionality in TUFLOW for both Classic and HPC solvers, including a range of new output options including new map output formats and data types, as well as plot output regions. Links to download: Downloads Page Release Notes Any queries or issues, please don't hesitate to email support@tuflow.com. And enjoy! Best Regards Bill Syme (TUFLOW Author and Manager)
  5. New Price List – First Update in 6 Years! We’re finally updating our price list, and offering new licensing options, for the first time since 2011! Note: the new prices come into effect on May 31st, 2017, but any new sales quotes issued prior to this time using the existing price list will be honoured within the 30-day expiry date of the quote. The 2017/2018 annual software upgrades and support fees will be based on the new price lists. Links to the new price lists are provided at the end of this post. The main points and changes are: Introductory Perpetual Licences (Local 1 to 4 and Network 1 to 3) remain unchanged for our base AUD rate. The monthly rental rate of 10%, and the annual software upgrades and support fee rate of 15%, remain unchanged. Australian rates are now listed including GST. Previously, the rates were excluding GST. GBP, USD and EUR prices better reflect current exchange rates relative to the AUD. Perpetual Licence prices have increased by up to 10% (depending on the currency) for Local 8 and greater and Network 5 and greater. The Local Licence multiple purchase discount has been reduced from 15% and 30%, to 10% and 20%, for the 2nd, 3rd, … licences to the same Licensee. The GPU Hardware Module (formerly GPU 2D Solver Module) is now priced in the same manner as other modules, i.e. as a percentage of the TUFLOW Engine price. For example, a Local 4 GPU licence is now simply 50% of the Local 4 TUFLOW price. Previously, GPU Licences had their own (somewhat confusing!) pricing structure. Of note is the new approach translates to lower prices for larger local GPU module orders. Yearly Subscription licences are now available. A Yearly Subscription is 40% of the Perpetual Licence price plus one year’s annual software upgrades and support fee. This option is also potentially very attractive to Licensees considering renting for 4 months or longer. Software Locks in addition to the existing Hardware (Dongle) Locks will be available with the 2017 release and potentially updates to past releases. Rental locks no longer need to be returned, but are covered by a one-off nominal purchase/admin fee. The Lock may be retained by the Licensee indefinitely for future rentals or purchases. The 50% of rental costs discount on Perpetual Licences is being discontinued (we will honour this discount for rentals invoiced prior to May 31st, 2017 if the rented licences are purchased at the end of the rental period). A new Cloud Simulation Service is now available. The BMT WBM Cloud Simulation Service is a bespoke service quoted at a per hour rate, which varies depending on the hardware, priority and order size. This service is suited to short term bulk simulations. For example, Monte Carlo simulations, where large numbers of simulations are to be completed within a short timeframe. TUFLOW Classic 2017 Release and the New HPC 2D Solver The new HPC 2D Solver (formerly referred to as TUFLOW GPU) is now included, at no extra cost, in the TUFLOW 2017 release for CPU processors. The 2017 release includes: TUFLOW Classic’s well-established 2D ADI Implicit Solver on CPU (single-threaded). TUFLOW’s new HPC (Heavily Parallelised Compute) 2D Explicit FV Solver, with 1st and 2nd Order options, on CPU (multi-threaded). Full 1D/2D linking and all 1D functionality available via the new HPC solver running on CPU or GPU devices. HPC’s 2nd Order Finite Volume solver offers similar performance to the world leading, proven and tried, TUFLOW Classic 2D Solver, with the addition of being unconditionally stable, mass conserving and benefiting from FV shock capturing. The HPC 1st Order solver was previously branded as TUFLOW GPU, but has now been further enhanced. Backward compatibility to the original TUFLOW GPU 1st Order Solver to be provided for legacy models. The GPU Solver Module is replaced by the GPU Hardware Module that can reduce HPC run-times by one or two orders of magnitude by allowing simulations to run across one or more GPU devices, significantly reducing TUFLOW licensing costs. The HPC Solver is also multi-threaded (parallelised) for CPUs. Links to New Price Lists Fixed Grid Modelling: TUFLOW Classic and HPC (formerly TUFLOW GPU) Solvers AUD: TUFLOW_Fixed_Grid_Modelling_Price_List_AUD.pdf EUR: TUFLOW_Fixed_Grid_Modelling_Price_List_EUR.pdf GBP: TUFLOW_Fixed_Grid_Modelling_Price_List_GBP.pdf USD: TUFLOW_Fixed_Grid_Modelling_Price_List_USD.pdf Flexible Mesh Modelling: TUFLOW FV AUD: TUFLOW_Flexible_Mesh_Modelling_Price_List_AUD.pdf EUR: TUFLOW_Flexible_Mesh_Modelling_Price_List_EUR.pdf GBP: TUFLOW_Flexible_Mesh_Modelling_Price_List_GBP.pdf USD: TUFLOW_Flexible_Mesh_Modelling_Price_List_USD.pdf miTools: All Currencies: miTools_Price_List_ALL.pdf Please don’t hesitate to contact sales@tuflow.com should you have any queries. Best Regards Bill Syme BMT WBM Software Business Manager
  6. We are pleased to announce an update to the 2016-03 TUFLOW Release (Build 2016-03-AE) is now available. It is recommended that all users update to this build. The changes consist of minor enhancements and bug fixes - please see Item 153 onwards at the end of the release notes for details. Links:Downloads Page2016-03 Release NotesLatest 2016-03 Manual (*.pdf) (Please note: A manual update commensurate with 2016-03-AE is to be uploaded in the coming week.) Any queries or issues, please don't hesitate to email support@tuflow.com. Best Regards TUFLOW Team
  7. Hi Sam Sorry, we're not quite sure where that line came from! Most of the functionality we've been using for large scale Monte Carlo simulations stepping of a single .tcf file were already built in (for example If Scenarios/Events, etc). The line has been removed from the release notes and I'll edit the above post. And yes, Set IWL == Auto was extremely useful for running 11,340 MC events, each with a different starting ocean level! Thanks for alerting us to the above. Cheers Bill
  8. We are pleased to announce an update to the 2016-03 TUFLOW Release (Build 2016-03-AD) is now available. It is recommended that all users update to this build. Note that some of the bug fixes may cause a change in results - please see the release notes for details. The most significant changes include: TUFLOW Classic: Bug fix if using the “Read GIS CWF ==” or “Read Grid CWF ==” commands. Licence free mode support for the new Tutorial Model 9 and the new Flood Modeller Pro - TUFLOW Tutorial. Up to 1,000 different soil classifications now allowed (previously 100). GPU Solver: Significant improvements in how the GPU Solver handles water level boundaries. New HQ boundaries based on a user specified water surface slope in a similar approach to TUFLOW Classic. Bug fix that caused strange results in occasional simulations when using soil infiltration in the GPU. An improved treatment of the eddy viscosity term in the GPU Solver (backward compatibility switch provided). Up to 255 soil classifications now allowed (previously 100). Links:Downloads Page2016-03 Release NotesLatest 2016-03 Manual (*.pdf) Any queries or issues, please don't hesitate to email support@tuflow.com. Best Regards TUFLOW Team
  9. We are pleased to announce an update to the 2016-03 TUFLOW Release (Build 2016-03-AC) is now available. It is recommended that all users of Builds 2016-03-AA and AB update to this build. The release notes provide a description of the 2016-03-AC improvements. The most significant include: TUFLOW Classic enhancements and bug fixes: New "Read GIS Zpt Modify Conveyance ==" .tgc command to easily increase/decrease waterway conveyance for sensitivity testing. Bug fixes to BB bridge inputs and above/below deck structure group output (these fixes do not change the hydraulic computations). New check files for structure groups. GPU Solver enhancements and bug fixes: Variable geometry (via 2d_vzsh layers) now supported in GPU for levee and dam breaches. ZUK0 hazard maximum output now tracked every timestep by the GPU Solver. Clarification of how to implement normal flow (HQ) boundaries in the GPU Solver. Bug fix if using the SRF (Storage Reduction Factor) in the GPU Solver. Links:Downloads Page2016-03 Release Notes2016-03-AA Manual (*.pdf) Any queries or issues, please don't hesitate to email support@tuflow.com. And enjoy! Best Regards TUFLOW Team
  10. We are pleased to announce that the TUFLOW Release 2016-03 is now available. To download the release and view the release notes please use the links further below. 2016-03 includes major new features and a range of enhancements along with minor bug fixes. There is also a new and updated manual in both pdf and word formats. The most significant changes are: Numerous GPU enhancements: Virtual Pipes. This feature provides a functional methodology to represent pipe drainage networks and cross drainage structures within a GPU model. Improved Source Area (SA) boundary options. All of TUFLOW Classic’s SA functionality is now supported by the GPU solver. Maximum outputs are now available. The GPU Solver now tracks the maximum value and time of maximum for water level, velocity and Z0 (VxD). Increased number of multiple GPU Cards available for parallel processing. Improved RAM allocation. This means even larger GPU models are possible! New and improved structure options: 1D Bridge options that automatically account for the losses due to flow contraction, expansion, and pressure flow. New time varying weir options. These are proving useful to simulate structures such as fabri (inflatable) dams. New grouped output options including combined structures (1D and/or 2D) can be associated with one another so model results can be output that are representative of the structure group. New Rainfall Control File. This creates a rainfall grid internally within TUFLOW based on point pluviograph rainfall data. Additional Map Output Formats: Now available for WaterRIDE, 12D, Delft-FEWS in NetCDF and also new direct GIS options. A new free version of TUFLOW allowing models to be developed and simulated within the following limits: 100,000 total cells and 30,000 active (potentially flooded) cells; 100 1D channels; One 2D domain; and A simulation time of 10 minutes. Links to download:Downloads PageRelease Notes2016 Manual (*.pdf) Any queries or issues, please don't hesitate to email support@tuflow.com. And enjoy!Best RegardsBill Syme(TUFLOW Author and Manager)
  11. The impending TUFLOW Classic and GPU release is now expected to be finalised during February and made available late February or early March. We are currently resolving a couple of (obscure) issues arising from a few of our 130 models we now benchmark against to check for backward compatibility, plus we can’t help ourselves and have been adding in some nice last minute requests. The delay is also caused by prior consulting commitments of key staff during February. Apologies from all us for the delay. Should you have any queries, please don’t hesitate to email us on support@tuflow.com. For some info on many of the new features you can view this pdf from a presentation at the UK TUFLOW Conference. Best Regards Bill
  12. Please note that this command has been renamed "Read GIS Objects RECORD GAUGE DATA ==" for the 2016 TUFLOW release (you can also use "Read GIS Receptors RECORD GAUGE DATA =="). The "USE ZC" and "ZPTS" options also remain available. The feature is essentially the same and now supports .shp format for the GIS layer written by TUFLOW. The main change, needed to accommodate the .shp format, is that all objects/receptors are output as point objects in one layer (irrespective of the number of input layers). For regions the point is located at the region's centroid. This feature is now documented in the 2016 TUFLOW Manual. Cheers Bill
  13. The UK TUFLOW Conference is looking to be another great get together and opportunity to learn and network. We are now approaching capacity for number of places, so if you are planning to come and haven't registered, please register ASAP or contact EdenvaleYoung to reserve a place. For details on the conference, the programme and how to register, please see this post. Looking forward to catching up with everyone and a warm beer! Best Regards Bill Syme
  14. The programme for the upcoming two day TUFLOW UK Conference 2015 is now available. The successful format of the previous 2013 Conference featuring three streams consisting of presentations, workshops and round table discussions has been retained. Both days contain a varied array of presentations delivered by leading flood risk management practitioners, TUFLOW developers and users, and our software partners. Beginning this week and leading up to the conference we will be showcasing some of these presentations to provide attendees with a taste of what to expect on the day. The conference is now only a few weeks away, so reserve your place soon using the event page: https://www.eventbrite.co.uk/e/tuflow-conference-2015-tickets-18033479623. We also encourage all attendees to join our official TUFLOW Users LinkedIn Group. We will be posting future announcements to this page and recommend the Group be utilised by attendees as a means of networking prior to, during and after the conference. Looking forward to meeting you there! Best Regards Bill Syme (TUFLOW Author and Manager)
  15. The Sydney Water Panel is running a full day 2D Modelling Workshop. Those with an interest in two-dimensional modelling and flood hydraulics should find this a fascinating insight into the current techniques for application in solving complex flooding problems. The workshop will also be a great opportunity to network and hear what other 2D modellers are doing. Highlights of the event include: Appraisal of approaches for assessing bridge losses using a 2D model Assessment of bridge losses using a range of 2D modelling tools – Gold Coast Case Study Sources of information which are available to validate numerical models (bridge hydraulics) Modelling Structures and Bends – Benchmarking Study Direct Rainfall versus Lumped Rainfall-Runoff Modelling Approaches The event will be held on 16th June 2015 at UTS Aerial Function Centre. Costs are: Members $250 + GST, Non Members $300 + GST. The event is now a little more than a week from now. It is very close to the last day for registrations as we will have to confirm final numbers at the venue within the next 24-48 hours. If you are interested please register ASAP at: https://goo.gl/lHVzbX or contact Peter Brady (peter.brady@wmawater.com.au) immediately. Full details are available at: http://www.sydneywaterpanel.org.au/ Looking forward to seeing you there. Best Regards Bill Syme
  16. Dear TUFLOW users, The TUFLOW FV developers are holding a TUFLOW FV New Features and Application Seminar. The seminar is free to attend and will be led by Dr Ian Teakle, the primary developer of TUFLOW FV. The seminar will be held in Brisbane, Melbourne and Sydney during 2015 with the Brisbane seminar scheduled for Thursday, 19 March 2015. Please see the flyer (link below) for more information about the seminar. Should you have any queries or wish to register please email training@tuflow.com. Flyer link: www.tuflow.com/Download/Flyers/150108_TUFLOW_FV_Training.pdf Best Regards Bill Syme
  17. We are pleased to announce the availability of Build 2013-12-AD, an update to the 2013-12 TUFLOW Release. It is recommended that all users of Builds 2013-12-AA to AC update to this version. The update includes: · A range of minor bug fixes. · New map output features/enhancements. · Materials check grid (similar to the new DEM_Z elevation check grid). · Other minor enhancements. Useful links: Release Notes (for changes due to 2013-12-AD see Items 75 to 92 on p42-46 shaded in red) TUFLOW Build 2013-12-AD (w32) Download TUFLOW Build 2013-12-AD (w64) Download Downloads Page Any queries or issues, please don't hesitate to email support@tuflow.com. Best Regards Bill Syme (TUFLOW Author and Manager)
  18. We’ve identified and fixed the bug that is causing the problem Alec describes. It occurs where there are both ESTRY and ISIS WLLs, and was introduced with the new map output zone feature, so is only in the 2013-12 builds. The bug allows only ESTRY or ISIS WLLs but not both. The bug fix will allow both ESTRY and ISIS WLLs as is the case for builds prior to 2013-12-AA. We’ll be incorporating the bug fix into the next update (2013-12-AD) and uploading in the next couple of weeks. Thanks Alec for sending your files through and your patience on this one. Cheers Bill
  19. We are pleased to announce an update to the 2013-12 TUFLOW Release (Build 2013-12-AC) is now available. It is recommended that all users of Builds 2013-12-AA or AB update to this build. The update includes: Much improved handling of 2D/2D linking of 2D domains. Models using the 2D/2D linking should upgrade to this build where possible. More new map output features and minor bug fixes. WaterRIDE .wrb output now works for TUFLOW DP simulations. Ability to adjust weir flow equation across HX 1D/2D link lines. Support for QGIS Version 2.2's handling of .shp layers. USA FMA Challenge Models can be downloaded as demo models and run without a licence. Enhancements and bug fixes to the GPU Solver. Other minor bug fixes. Useful links: Downloads Page Release Notes (changes highlighted in blue) TUFLOW Build 2013-12-AC (w32) Download TUFLOW Build 2013-12-AC (w64) Download Any queries or issues, please don't hesitate to email support@tuflow.com. We now have very few bugs or known issues with the 2013-12 release, so our focus is nearly 100% on major new features for the 2014 release (and of course updating the manual which is in progress!). In the meantime, enjoy! Best Regards Bill Syme (TUFLOW Author and Manager)
  20. We are pleased to announce an update to the 2013-12 TUFLOW Release (Build 2013-12-AB) is now available. It is recommended that all users of Build 2013-12-AA update to this build. The update offers some nice new enhancements and features along with bug fixes including: Support for reading and outputting binary grids (much much faster than .asc grids). Scenarios and events are automatically available as variables anywhere within your control files. New cell width factor adjustment layer. Can now control which attribute to read from GIS layers. New Horton soil infiltration option. Restart files are time-stamped. .xf files can be made model dependent so different models can use the same DEM(s) without re-sampling. The GPU solver now supports form loss coefficients, storage reduction factors, cell width factors, and the new Horton soil infiltration option. Blue Kenue and the SMS TRIANGLES option output now works. Bug fixes to soil infiltration if using US Customary Units with manually specified parameters. Range of other minor enhancements and bug fixes. Useful links: Downloads Page Release Notes (changes from 2013-12-AA highlighted in green) TUFLOW Build 2013-12-AB (w32) Download TUFLOW Build 2013-12-AB (w64) Download Any queries or issues, please don't hesitate to email support@tuflow.com. And as always, enjoy! Best Regards Bill Syme (TUFLOW Author and Manager)
  21. We are pleased to announce that the TUFLOW Release 2013-12 is now available and offers a range of exciting new features and enhancements. To download the release and view the release notes please use the links further below. The most notable changes, new features and enhancements are: · GPU Module allowing 2D models of hundreds of millions of cells to be run hundreds of times faster. · New map output formats including direct writing of 12D, waterRIDE, Blue Kenue and GIS Grids. · New triangular mesh format for SMS .dat and .xmdf formats that includes the results at the cell centres. · Ability to assign different map output settings to different output formats. · Output Zones that allow you to produce map output in different formats, different time resolutions, different data formats, etc for different regions within your model. · Much improved interpolation/extrapolation to the 2D cell corners at the wet/dry front that resolves issues associated with tracking maximums and inconsistencies between events of different probability. · New .csv time-series format for our GIS based time-series results viewer. · New 1D structures including pumps, sluice gates, radial gates, Q (stage-discharge) channels, spillways and eight types of weirs. · Operational controls of gated rectangular culverts, pumps, sluice and radial gates, Q channels and gated spillways via simple logical scripts. · Direct reading of land .xml TINs that can be exported from software such as AutoDesk’s Civil3D. · SA inflows via GIS streamline layer(s). · New _DEM_Z ASCII grid check layer of your final model ground/bathymetric elevations. · Control of which GIS check layers are output, and output of the large check layers (DEM_Z, 2s_zpt, 2d_grd, 2d_uvpt) for output zone(s). · User defined variables in your control files. · You can now use “If Event ==” in the same way you can use “If Scenario ==”. · .qgs project file that allows you to open all input and output (check) layers in QGIS. · Specification of a road crossfall slope to improve the capture of water at pit inlets. · _mmQ GIS layer has two additional attributes for the drop and slope in peak water level along channels. · 2D variable Z shapes can now be triggered based on 1D water level(s). · New folders are now automatically created (no dialog query prompt anymore). · TUFLOW Override files that allow you to specify computer dependent .tcf and .ecf commands. · Issues relating to 2D PO flow lines slowing down simulations resolved. Links to download: Downloads Page Release Notes TUFLOW Build 2013-12-AA (w32) Download TUFLOW Build 2013-12-AA (w64) Download Any queries or issues, please don't hesitate to email support@tuflow.com. And enjoy! Best Regards Bill Syme (TUFLOW Author and Manager)
  22. Hi Laura Can you please email the .tlf file to support@tuflow.com. Thanks Bill
  23. Hi Laura The K value should be set equal to the 2*g*dh/V^2 where g is gravity (9.81), dh is water level drop and V^2 the velocity squared. Note that by default TUFLOW does not adjust the loss coefficient for bridges by the approach/departure velocities as is done (by default) for culverts, as the effect of the approach/departure velocities are usually taken into account in the derivation of bridge losses (as is the case for Hydraulics of Bridge Waterways and may or may not be the case for HEC-RAS depending on whether you specify "no flow" zones on the sides of your cross-sections upstream/downstream of the bridge). You can have TUFLOW adjust the loss according to the approach/departure velocities by specifying the A flag (ie. a BA channel). For more info, please see Section Adjustment of Contraction and Expansion Losses of the 2010 TUFLOW Manual. This post may also be useful: http://www.tuflow.com/forum/index.php?showtopic=1259. Cheers Bill
  24. Hi Faye Once the bridge deck is submerged there will still be losses, so it would be incorrect to reduce your losses to zero (usually the deck loss value is maintained above the deck). You will also need to have a weir structure if there is flow over the bridge deck (this can be automatically done by specifying a BW channel - see "Weir over the Top" entry at the end of Table 4.13 in the 2010 TUFLOW manual) or manually by digitising a W channel. If you don't have a weir structure, and there is flow over the deck, then the losses will be overestimated as all the water is being forced under the bridge forcing your velocities to be artificially high, and therefore your losses will be high (losses are proportional to velocity squared so it is very important to get the velocity correct). The 1.56 is a conservative value and it is entirely appropriate to use a smaller value if Hydraulics of Bridge Waterways (which AustRoads is based on) or other literature indicates so. The losses at a bridge structure are highly complex (it's really a 3D CFD problem!) and will vary significantly depending on the bridge shape/dimensions, approach/departure velocities, embankment configurations, etc. If the bridge is a critical structure you may also want to cross-check loss values by making a simple HEC-RAS model of the structure. Also see this post: http://www.tuflow.com/forum/index.php?showtopic=1258 I hope this helps. Cheers Bill
  25. Hi Fil The D flag will force a culvert to only consider the downstream controlled flow regimes (except when the culvert is treated as having a zero length, ie. less than 0.01m). As-a-rule this option is rarely if ever used (so please cross-check the results!), and it may lead to incorrect flows being computed through the culvert. A culvert with the D flag would be a CD or RD Channel_Type in the 1d_nwk layer. For more information, see Table 4.13 1D Channel and Node Types in the 2010 manual. There is no option to force a culvert to only run as inlet control other than making sure the downstream water level is always below the invert (or below critical depth). Cheers Bill
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