Product(s): WaterGEMS, WaterCAD, HAMMER, SewerGEMS,CivilStorm,SewerCAD, StormCAD, PondPack Version(s): 08.11.XX.XX and later (features vary) Environment: N\A Area: Licensing Problem When Clicking Make Default in the Municipal License Administrator the following error appears: "Bentley.lictransmit for Windows has stopped working" Solution Perform a clean uninstall and reinstall as described in the following article. How do I perform a clean uninstall and reinstall of the Hydraulic and Hydrology products? See Also Hydraulics and Hydrology Product Licensing (Activation) FAQs and Troubleshooting [TN] Hydraulics and Hydrology product licensing (activation) SELECTsupport TechNotes And FAQs Product TechNotes and FAQs Original Author: Craig Calvin
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Wiki Page: [DELETED]Licensing Error: "Bentley.lictransmit for Windows has stopped working"
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Wiki Page: Licensing Error - "LicenseTool for Windows has stopped working"
Product(s): WaterGEMS, WaterCAD, HAMMER, SewerGEMS, SewerCAD, StormCAD, CivilStorm, PondPack Version(s): 08.11.XX.XX and 10.00.XX.XX Area: Licensing Problem When trying to activate a license for Bentley Hydraulics and Hydrology products, the license will not activate. One of the following error messages may appear "Bentley.lictransmit for Windows has stopped working". "LicenseTool for Windows has stopped working" Solution 1. Perform a clean uninstall and reinstall as described in the following article. See: How do I perform a clean uninstall and reinstall of the Hydraulic and Hydrology products? 2. Download and install the latest update for the storm and sewer product. See: Cumulative Patch Sets for Hydraulics and Hydrology Products See Also Hydraulics and Hydrology Product Licensing (Activation) FAQs and Troubleshooting [TN] Haestad Product TechNotes And FAQs
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Wiki Page: Can simple or logical controls be used during a transient simulation?
Product(s): HAMMER Version(s): 08.11.XX.XX and 10.00.XX.XX Area: Modeling Problem Can simple or logical controls be used during a transient simulation? Background HAMMER is a transient modeling software and does not have the ability to use controls during the transient analysis. The controls that you enter under Components > Controls only apply to the initial conditions calculation, and do not apply to the transient simulation. To control elements during the transient simulation, you'll need to use configuration in the individual equipment (such as closure time for the check valve node) or operating rules (such as the pattern of time vs. relative closure for a valve). The steps below are designed using an example of having a bypass pipe going from the discharge side of a pump to the suction side to recycle water. On the bypass pipe there is a TCV and that needs to open when the pressure in a given downstream pipe reaches a given pressure. Solution Run the model, observe the results, create a pattern, rerun the model Make sure the model is set up correctly and run the initial conditions. The initial conditions should have the TCV being in a closed state with the Transient (Operational) Operating Rule set to fixed. Run the transient simulation Observe the results of this situation so that a pattern can be created to assign to the TCV and pump. You're looking for the time the pressure in your downstream pipe hits that critical pressure. The pattern is going to be designed based on this time. Go to Components > Patterns > Create a new Operational(Transient, Valve) pattern. This is a pattern based on the time from start (sec) vs. the relative closure (%). Note that a relative closure of 0% means the valve is 0% closed, or 100% open. Conversely, a relative closure of 100% means the valve is 100% closed, or 0% open. If the valve is supposed to open at 5 seconds the pattern might look as follows. Time from Start (sec) = 1 , Relative Closure(%) =100 Time from Start (sec) = 5 , Relative Closure(%) = 0 Time from Start (sec) = 400 , Relative Closure(%) = 0 This pattern assumes the valve open immediately and fully at 10 seconds. You can adjust you pattern to suit your needs if you valve fully opens over a period of time. Once this is done assign the pattern to your TCV valve. 5. You will need to do the same thing for you pump if you intend to shut it down too. Go to Components > Patterns > Create a new Operational(Transient, Pump) pattern. This is a pattern of Time vs. a Multiplier where the multiplier is 0 for off and 1 for on. 6. Rerun your model and observe the results. See Also Haestad Product TechNotes And FAQs
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Wiki Page: Why do I need to enter a "nominal head" and "nominal flow" when modeling a pump startup event?
Product(s): HAMMER Version(s): 08.11.XX.XX and 10.00.XX.XX Area: Layout and Data Input Problem Why do I need to enter a "nominal head" and "nominal flow" when modeling a pump startup event? Solution When modeling a pump startup event by using the "pump start - variable speed/torque" transient pump type, the "nominal head" and "nominal flow" represent the operating point of the pump once it has started up and reached full speed. The reason why this is needed is because HAMMER uses a special 4-quadrant pump curve during the transient simulation (not your pump definition) which has points that are relative to the nominal operating point. So, since the initial head/flow are zero in this case, HAMMER needs you to enter the nominal operating point, so it's able to use the 4-quadrant pump curve. Typically you would simply compute a steady state simulation with the pump on, record the operating point, turn it back off, then use that for the nominal head/flow. See Also Haestad Product TechNotes And FAQs Modeling A Pump Start-Up Transient Event In Bentley HAMMER V8i [TN] Is it possible to model more than one pump starting up at the same time? Pump Startup occurs too quickly / initial upsurge too severe
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Wiki Page: [DELETED] General StormCAD [FAQ]
Applies To Product(s): Bentley StormCAD Version(s): V8i Environment: N/A Area: N/A Subarea: N/A Original Author: Nancy Mahmoud, Bentley Technical Support Group Where did the flow go? Why is Flow in not equal Flow out? StormCAD uses the rational method which is only concerned with peak flows and has a high dependence on duration (system time). StormCAD does not simply add flow at a junction node; rather, it takes into account the attenuation of peak flow as it moves downstream by keeping track of upstream catchment properties and decreasing the peak intensity according to the time of concentration and travel. See more here: http://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/17061.why-does-flow-sometimes-decrease-when-moving-downstream-solution-500000075879.aspx Why is Known Flow not adding up? Flown (Known) remains constant as they travel downstream and combine with other flows, similar to additional loads. Known flows override upstream known flows in the system (only when it’s a non-zero flow), the local known load replaces the upstream known load, rather than the local known load adding directly to the upstream known load. Why is it sometimes a pipe whose calculated depth is below the pipe top has "Capacity (Flow/Full Flow)" above 100%. What is the meaning of Full Capacity? The Full Capacity is the flow through the pipe if normal depth were equal to the top of the pipe. You can verify this by using a simple Manning's equation normal depth calculator such as Bentley Flowmaster. However, StormCAD computes a varied flow profile. So, the HGL slope can be changing over the length of the pipe and thus depth can be different than normal depth and this "full capacity" value may not be a good thing to refer to. Also, dynamic effects such as momentum and tailwater are accounted for. So, your profiles are likely not flowing at normal depth, which is why they seem to be at odds with the full capacity values. You may want to look at the "depth/rise" result field instead. This is the middle depth of the pipe divided by the diameter/rise, which gives you an idea of how full the pipe is at the midpoint. See also: http://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/12438.why-does-the-profile-for-the-system-appear-to-be-at-odds-with-the-results-for-the-capacity.aspx Why is it that no matter how large the inlet on grade is the gutter spread always remains the same? HEC-22 inlet computations are concerned with when the gutter spread is maximum, which is immediately upstream of the inlet. Just downstream of the inlet, the spread is at its minimum because most, if not all, of the water has been intercepted. The spread is calculated for the flow in the gutter immediately upstream of the inlet, so the size of the inlet does not impact the width of the gutter spread. To remedy this situation, try increasing the size of the inlet(s) upstream of the inlet you have been working on. See also: http://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/29821.why-is-it-that-no-matter-how-large-the-inlet-on-grade-is-the-gutter-spread-always-remains-the-same Why is the HGL reset to rim elevation for flooded structures? See the following support solution for information: https://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/11166.why-is-the-hgl-reset-to-rim-elevation-for-flooded-structures.aspx Why do hand calculations for Rational Method flow in U.S. Customary units differ from the values presented in the software? See the following support solution for information: http://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/25381.why-do-hand-calculations-for-rational-method-flow-in-u-s-customary-units-differ-from-the-values-presented-in-the-software Is it possible to model a culvert in StormCAD? See the following support solution for information: http://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/27718.can-stormcad-use-the-hds-5-calculation-that-culvertmaster-uses-to-compute-culvert-hydraulics Why does the hydraulic grade line at my outfall start at a higher elevation than the user defined tailwater I entered? See the following support solution for information: https://communities.bentley.com/products/hydraulics___hydrology/w/hydraulics_and_hydrology__wiki/17510.why-does-the-hydraulic-grade-line-at-my-outfall-start-at-higher-elevation-than-the-user-defined-tailwater-i-entered See Also Product TechNotes and FAQs Haestad Methods Product Tech Notes And FAQs Licensing TechNotes and FAQs External Links Bentley LEARN Server
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Forum Post: Community Survey of Haestad Users
We are currently surveying our Haestad users for honest and direct feedback regarding their experience with our Events and Communities. If you can please take this survey, it is only open for a limited time. Typically, it only takes about 10 minutes to complete. Click Here to Start the Survey Thank you for your time and attention, and if you have any questions, comments, or concerns please let me know. Seth Guthrie, SE Director of User Success Analytical Modeling Products
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Wiki Page: Filtering the Sanitary Load or Inflow Control Center by attribute or by selection set
Applies To Product(s): SewerCAD, SewerGEMS, CivilStorm, StormCAD Version(s): 10.00.xx.xx, 08.11.xx.xx Area: Modeling Original Author: Jesse Dringoli, Bentley Technical Support Group Problem Is it possible to apply a filter the Sanitary Load or Inflow Control Center by attribute or by selection set? Problem Number: 35188 Background Typically, you would be able to filter elements in the element FlexTables . However, since the Sanitary Load Control Center and the Inflow Control Center can have multiple entries for a single element, it is not possible to filter the FlexTables by loading data. It is possible to filter like this in the control center dialogues. This allows the user globally edit only certain elements, while leaving the original values set as they were. In the CONNECT Edition of the product, you can open the control centers by going to the Home tab and choosing Loading > Sanitary Load Control Center or Inflow Control Center. In the V8i releases of the product, go to Tools > Sanitary Load Control Center or Inflow Control Center. Filtering by Attribute Once you are in the Sanitary Load Control Center or Inflow Control Center, choose the Options button, then select Filter > Custom. You can then choose the attribute you want to filter by from the pulldown menu in the Attribute column. Then you would select the Operator and the value you want to filter by. Filtering by Selection Set First, a selection set would need to be created. Once that is done, double-click on the selection set to highlight the elements in the drawing. Once this is done, open the Sanitary Load Control Center or the Inflow Control Center. Next, click the Options button and choose Filter > Current Selection. This will filter the table by only the elements in the selection set and allow you to make necessary changes. If you are using version 08.11.02.75 and earlier: The steps above will not work if you have older version of the storm-sewer products. Below you can find the steps to do this in these older versions. 1. Go to View > Selection Sets and double-click the selection set in question to select the element in the drawing 2. Go to View > FlexTables, right-click the manhole predefined FlexTable and choose "Open on Selection" 3. In the Manhole table, click the Options button and click "Relabel" 4. Choose "Append" as the operation and type in a unique string of characters for the "Prefix" field. For example, "SELECTIONSETA" 5. Click OK, close the manhole FlexTable, and open the Sanitary Load Control Center 6. Click Options > Filter > Custom. Choose "Label" as the attribute, "Begins With" as the operation, and "Value" for the Prefix 7. Click OK. You will now only see loads for manholes that are part of your selection set. 8. When done with your edit, you can restore the manhole labels by reopening the "Relabel" tool in the manhole table, choosing "Replace" as the operation and then your prefix in the "Find" field. "Replace with" will be blank, since you will essentially be deleting the prefix you had added in step 4. See Also Why are there entries for multiple elements in the Sanitary Load Control Center or the Inflow Control Center?
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Wiki Page: Differences between solvers: GVF-Convex vs. GVF-Rational vs. Implicit vs. Explicit (SWMM)
Product(s): SewerGEMS, SewerCAD, CivilStorm, StormCAD Version(s): 10.00.xx.xx, 08.11.xx.xx Area: Modeling Problem What are the differences between the SewerCAD (GVF Convex Solver), SewerGEMS/CivilStorm (Implicit and Explicit Dynamic solvers), and StormCAD (GVF Rational Solver)? When should I use StormCAD instead of CivilStorm? Solution The SewerCAD GVF Convex solver uses convex routing and a gradually varied flow profile for design and analysis of of sewer networks including mixed gravity and pressure flow. SewerGEMS is a superset of SewerCAD, including all its functionality, plus two fully dynamic solvers (Implicit and Explicit) and ArcGIS integration support. SewerGEMS Sanitary was a separate program included with older versions of SewerGEMS V8i (08.11.01.21, 08.11.02.46, 08.11.02.49 and 08.11.02.75). It is installed automatically when installing these versions of SewerGEMS and includes all the functionality of the Bentley SewerCAD product, plus the ability to work inside of ArcGIS. As of SewerGEMS V8i SELECTseries 3 (08.11.03.77+) SewerGEMS Sanitary is no longer available with this specific brand name because of the conversion of all of our storm and sewer products into a unified file format. The unified file format now allows all the storm sewer products (StormCAD, SewerCAD, SewerGEMS, CivilStorm, and SewerGEMS) to open a model created in another product. In creating the unified schema SewerGEMS has been changed to incorporate all the storm sewer solvers, so if you want to run the SewerCAD solver (GVF-Convex) on your network you have the option to. This is really the same thing as having SewerGEMS Sanitary come with SewerGEMS, except you no longer need to open a separate program, and you also have the option to run the GVF-Rational (StormCAD) solver for your model if you choose. In other words, With the SewerGEMS SS3 release Bentley accomplished a convergence of SewerGEMS Sanitary modeling fully into SewerGEMS. As a result SewerGEMS embodies effectively a superset of the capabilities delivered in StormCAD, CivilStorm, SewerCAD, and SewerGEMS. All consolidate into a common data store. All differentiate by the computational solvers that are selectively packaged into each product in service to a range of commercial use-cases across stormwater, sanitary, and combined systems. With this release SewerGEMS Sanitary was deprecated. It was cleanly folded into the SewerGEMS application. How do I know which solver is best for me to use? SewerCAD (GVF Convex) vs. SewerGEMS (Implicit and Explicit) The SewerCAD application (and the GVF Convex numerical solver in SewerGEMS) is best used in systems that have complicated pumping, pressure sewers, and only need to use extended period simulation convex (EPS) routing as opposed to fully dynamic routing. SewerCAD should also be used if you need to perform a constraint-based automated design or if you need to run a steady state simulation, such as for a peak flow analysis with Extreme Flow methods. SewerCAD can be thought of as a bread-and-butter package that delivers conventional design and capacity analysis. Municipal-scale master planning is certainly part of it, but serves very well in site/civil arena as well. Routing is hydrologic with conventional back-water dominant hydraulics. Gravity analysis is complete with well-accepted state-of-the-practice hydraulic grade analysis with form losses. Diversions or splits are handled in explicit ways. I&I, similarly, is modeled using an array of fundamental and appropriate simplifying models. On the other hand, the SewerGEMS/Civlstorm applications layer into the mix solvers for dynamic wave simulation (implicit and explicit (SWMM), with ArcGIS integration support. So, if you have challenging cross-connections, loops or dynamic surcharging and ponding, this gives you the capabilities of EPA SWMM along with Bentley's own implicit solver. SewerGEMS (Implicit or Explicit Dynamic numerical solvers) is best for analyzing existing problematic systems, where catchment rainfall-runoff calculations are required or dynamic wave solutions are needed (if required by the reviewer or by way of the complicated nature of the particular network) or if you must work inside the ArcGIS platform. SewerGEMS can handle complex things like control structures, diversions (without having to enter a diversion rating curve required in SewerCAD/GVF Convex solver) or ponds. Long term continuous simulations would be done using the Explicit solver in SewerGEMS. The "solver" refers to the type of numerical finite difference solution used to solve the St. Venant equations, which describe unsteady one-dimensional, free surface flow. The software contains two different solvers:: Implicit solver - Uses a four-point implicit finite difference solver to find the numerical solutions for the hydrodynamic Saint-Venant equations. The implicit solver tends to be more stable than an explicit solver. This solver is based on the National Weather Service FLDWAV model. Explicit solver - Uses the solver from the EPA Stormwater Management Model version 5 (SWMM). This is an explicit solver which is more prone to stability problems. The results from this solver should exactly match the results from SWMM 5. There is an initial elevation attribute for manholes using the SWMM engine so that the calculation can simulate a filling process if the initial elevation is lower than the downstream start elevation. However in the Implicit engine the manhole initial elevation is not considered, so the initial manhole elevation is assumed to be the same as the downstream start elevation. Inflow hydrographs are also handled differently by the two engines. The implicit engine interpolates flows between the final flow in the hydrograph and the end time. The SWMM engine assumes that all flows after the final inflow point are zero. *Note: If a catchment is using the EPA SWMM runoff method and not using the default infiltration method specified in the SWMM calculation options then neither hydrology or network will calculate. If you are not using the EPA SWMM runoff method, then any combination of other runoff methods can be used. GVF-Convex (SewerCAD) solver is not intended to handle overflow situations such as a case where you want to analyze a problematic existing system. When an overflow condition arises with the GVF Convex solver, the HGL is reset to the rim for an overflow condition. However, the dynamic solvers in SewerGEMS (Implicit and Explicit SWMM solvers) do handle overflow, as they are intended for situations like this (problematic existing systems and/or complex situations). SewerGEMS Implicit and Explicit solvers automatically calculate the overflow using the weir equation. So, SewerGEMS differentiates in the market as being a singular, "top of the line" tool that will carry the engineer though all stages of design and analysis from conventional capacity and automated design of pipe networks into complex hydraulics of combined-sewer systems. SewerGEMS will handle both storm and sanitary models. Importantly, if you have any old StormCAD, SewerCAD or CivilStorm files they can all be loaded into SewerGEMS and brought cleanly ahead. The GVF Rational Solver Note: Currently the StormCAD numerical solver is included with CivilStorm, so CivilStorm has all of the functionality of StormCAD included, by way of selection of GVF Rational as the active numerical solver. The StormCAD product (and the GVF Rational Solver in SewerGEMS and CivilStorm) uses the rational method to analyze or design a system under peak flow conditions based on peak rainfall intensity, while the other solvers in CivilStorm and SewerGEMS such as the Implicit or Explicit, takes rainfall hyetographs (rain vs. time) and develops hydrographs (flow vs. time) for each pipe and routes the flows dynamically. If you are studying a small area where only peak flow is of interest, or if you need to design a system based on the standard rational method, then StormCAD or the StormCAD solver (GVF Rational) should be adequate. If you are working on a large area where hydrograph routing and storage are significant, where you need to use a dynamic solver, or if you need to otherwise analyze more complex effects such as flooding and controls structures, then the Implicit and Explicit solvers in CivilStorm (or SewerGEMS) is what you need. If you get involved with combined sewers where rain and sanitary sewage is carried in the same pipe, we recommend you use one of the dynamic solvers in SewerGEMS. See Also StormCAD FAQ SewerCAD FAQ SewerGEMS FAQ
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Forum Post: Query on drainage
Hello!I I have created 2 manholes on either sides and annotated them also on the active alignment after creating one drainage file. Between these manholes i have created a channel.But when i go to create profile and when i give the following inputs and say apply the second below window is popping up.Can you please help me to understand where i am going wrong and what is the meaning of this window message.
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Wiki Page: Modeling Reference - Headwalls
Applies To Product(s): CivilStorm, SewerCAD, SewerGEMS, StormCAD Version(s): 10.00.xx.xx, 08.11.04.xx and later Area: Modeling Original Author: Sushma Choure, Bentley Technical Support Group Introduction The new element which is introduced with the release of SS4 is the headwall. This technote explains about general structure of headwall as an element. The Headwalls are generally concrete or masonry retaining walls, which are placed at the outlet side of a drain or culvert. Headwalls should be designed as such by considering factors such as earth pressure, loading and soil properties. The Headwall element has been added in SS4 in order to support subsurface utilities projects allowing users to directly analyze and design these structural elements without having to insert inlet and/or cross-section elements as proxy hydraulic elements. The Headwall element is available for modeling in the layout toolbar as shown below. Headwall node within the Standalone Layout Toolbar A headwall node that is the Start Node to a conduit will be laid out as a mirror image to headwall node that is a stop node. A headwall can only be designed for a closed conduit and only a conduit link can be used to model a culvert. It is not possible to connect two conduit links with a headwall node during layout. By hydraulic convention, culvert entrances usually have end-treatments that correspond to headwalls at the entrance and endwalls at the outlet. But we will refer to all end treatments, regardless on upstream or downstream location or structural aspect as Headwalls. While setting up the headwall in the model you need to define the referenced culvert in the properties of the headwall as seen below. A conduit that is declared to be a culvert link may have a headwall node at either end. Conduits can be set as culverts by changing "Is Culvert?" property to 'True' in the properties of the conduit. You may model projected or mitered end treatments on a culvert link with connection to a cross section or outfall node. Different possible combinations of headwalls can be seen below. If you attempt a configuration that is not permissible, you will get user notification for that. You may model projected or mitered end treatments on a culvert link with a connection to a cross section or an outfall node. Different possible combinations of headwalls can be seen below. If you attempt a configuration that is not permissible, you will get user notification for that. More Valid Configurations: Culvert with channel links Some Invalid Configurations, yet possible to layout. User notifications expected Headwall Property Grid: Basic Attributes The following attributes of a headwall node are visible in the headwall property grid. Headwall Property Grid Culverts in SS3 & in SS4 Culverts in SS3 used to be designed using a cross section node at the end. Culvert inlet coefficients could be specified through conduit properties. With release of SS4 headwalls can be designed for the culvert at one end or at both the ends. A comparison can be seen in the screenshot below. Culverts in SS3 & Culverts in SS4 The headwalls are the end treatments of the culverts. If you need to model a headwall there has to be an adjacent culvert for that. Set the 'Is Culvert?' to 'True' in the properties of the conduit and then upstream and downstream headwalls in the physical properties of culvert (see screenshot above). Culvert inlet Coefficients: In previous software releases you could reference an entrance loss and other Form 1 and 2 coefficients by selecting a culvert inlet coefficient engineering library data instance through the conduit property grid as seen below. Selection of Culvert Library Data from Conduit Property Grid in Bentley SewerGEMS SS3 Starting with SS4, element manager called the 'Culvert Inlet Coefficients' dialog is accessible from the Components menu, appearing just after Conduit Catalog. The manager dialog is similar to Conduit Catalog manager, including sync capabilities to the Culvert Inlet Coefficients type of engineering library data. The headwall section properties can be set through the headwall property grid & as well as the conduit property grid. The Culvert Inlet Coefficients manager dialog has two label columns: Label and Barrel Shape. Mock-up of Culvert Inlet Coefficients dialog All the attributes of culvert inlet coefficients engineering library data are mirrored and made available for editing in the right side of the dialog. From a headwall property grid, you can reference from the culvert inlet coefficient manager by selecting […] from inlet description. This function is similar to selecting a conduit catalog reference. A non-editable preview of referenced support element data values is displayed in the corresponding fields in the headwall property grid. Conduit Property Grid & Headwall Property Grid in SS4 The culvert barrel shape field reflects as a read-only value of the downstream conduit’s shape if the headwall node is a start node. It reflects the value of the upstream conduit shape if it is a stop node. The read-only 'Is Inlet?' attribute is 'True' if the headwall node is a start node. It will be set to 'False' if the headwall node is the connected downstream node of the culvert link. Boundary types of Headwall Inlet Intermediate Free outfall Discharge to Pond Pond Outlet Headwall with no upstream connections- Inlet A headwall node can be the most upstream node in a gravity sub-network, similar to other gravity network nodes. In this case, a derived result field 'Boundary Type' will have value of 'Inlet'. This value is presented in headwall property grid when it detects there is no incoming link. The default value of this attribute is 'Intermediate', if headwall is an intermediate element in the model. When the node has a state of 'Inlet' or 'Outlet', the 'Cross Section' related attributes are visible in the property grid but they will not be validated, you will get a user notification – Cross section dimensions are ignored. Conduit attributes are used instead. Headwall with no downstream connections – Free Outfall A headwall node can be the terminal point of a gravity sub-network, in place of an outfall element. In this case, a derived result field "Network Boundary Type" has value of "Outlet". This value is presented in headwall property grid when it detects there is no outflow link. Headwalls as end nodes for a channel By setting the headwall property field "Has Cross Section?" to True, you can place a channel between two headwalls. When you set this to True, you will be able to enter the start and/or stop properties for an irregular or trapezoidal channel. Headwall as an alternative to a Pond Outlet Structure In previous releases, only the Pond Outlet Structure node modeled the downstream connections in the network from a pond. But you may now model the Pond outflow through a headwall node and culvert link. When headwall node is not a stop node (the headwall node has no incoming channel or conduit link), When a headwall node is at an upstream end of the network with no upstream elements, then the upstream pond can be connected to headwall, which will act as pond outlet structure, if required. A dashed line connected to pond will be drawn, with the same behaviour as a pond outlet structure node. In this configuration, the 'Boundary Type' is set to 'Pond Outlet'. Valid configuration: Headwall instead of a Pond Outlet Structure. Headwall empties to a Pond If the headwall node has no outgoing link, then user can select the 'Boundary Element' option, so the Boundary Element field can be used from the headwall property grid to select a neighboring downstream pond. This mimics the function of an outfall to pond connection. In this configuration, the 'Boundary Type' is set to 'Pond Inlet'. Property grid state for Headwall when selecting a Pond as a Boundary Element. Valid configuration: Headwall empties to a Pond. Profile View: The headwall element can be seen in the profile view as below, wherein the drop in the HGL is seen in the conduit. Limitations of Headwall: At a headwall node you cannot have: J unction headloss Locally injected sanitary flows Incoming conduit (closed Pipe shape) links Outgoing conduit (closed Pipe shape) links Headwall elevations are not modified during Design run Headwalls cannot be designed using Explicit SWMM solver Velocity Head (In-Governing), because multiple incoming pipes are not permitted Elevation (Invert in 1, 2, 3…), because multiple incoming pipes are not permitted Sample File You can download the sample file of H eadwall model from the below mentioned link. http://communities.bentley.com/products/hydraulics___hydrology/m/hydraulics_and_hydrology_gallery/270016.aspx
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Wiki Page: Source of the default Specific Speed for pumps and turbines
Applies To Product(s): HAMMER Version(s): 10.00.xx.xx, 08.11.xx.xx Area: Modeling Original Author: Jesse Dringoli, Bentley Technical Support Group Problem In the Transient tab of a pump definition, there are several default selections available for Specific Speed. What is the source of the 4-quadrant characteristic curves behind these specific speeds? Also - what is the source of the curves behind the default Specific Speeds for turbines Solution Pumps For Pumps, the specific speeds 25, 94 and 145 (SI units) were derived from data published by Stepanoff (1957), as well as personal correspondance, in terms of relative Q and N along lines of constant head and torque throughout the entire operating range. The other default specific speeds are from Thorley, A.R.D and A. Chaudry., "Pump Characteristics for Transient Flow Analysis", Department of Mechnical Engineering & Aeronautics, City University, London ECIV OHB Turbines For turbines, the specific speeds 115, 170 and 230 (SI units) are from published data from the US Bureau of Reclamation (USBR).
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Wiki Page: Differences between the Constant Speed transient pump types
Applies To Product(s): HAMMER Version(s): 10.00.xx.xx, 08.11.xx.xx Area: Settings/Attributes Original Author: Jesse Dringoli, Bentley Technical Support Group Problem What is the difference between "Constant Speed - Pump Curve" and "Constant Speed - No Curve", for the transient pump type? Solution "Constant Speed - Pump Curve" - This option is used to represent a pump that does not change speed (no shutdown or start up) and operates only in the first quadrant. (no negative flow) It utilizes the pump definition selected in the pump properties (instead of a 4-quadrant curve) to adjust the flow produced by the pump in response to changing system heads at its suction and discharge flanges throughout the simulation period. Use this option if the constant speed pump will only operate in the first quadrant during the transient simulation (no reverse flow.) "Constant Speed - No Curve" - A pump that operates at constant speed throughout the simulation, using a built-in 4-quadrant characteristic curve based on the selected specific speed (in the "transient" tab of the pump definition). Use this option if the constant speed pump can operate in all 4 quadrants (reverse flow possible) or if a pump definition is not available (in which case you would only need to enter the nominal head and flow). See Also Source of the default Specific Speed for pumps and turbines General HAMMER FAQ
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Wiki Page: Submodel Import/Export
Applies To Product(s): WaterGEMS, WaterCAD, HAMMER, StormCAD, SewerCAD, SewerGEMS, CIvilStorm, PondPack Version(s): CONNECT Edition, V8 XM and V8 i Area: Modeling Original Author: Mark Pachlhofer, Bentley Technical Support Group Overview This TechNote will show you how to import one model file ("submodel") into another model file ("target"). It is meant to provide clarification and explanation beyond what is given in the Help documentation. Note that this Technote was written for WaterCAD and WaterGEMS but the same concepts apply to HAMMER, StormCAD, SewerCAD, SewerGEMS, CIvilStorm and PondPack (V8i and V8 XM.) Definitions Target Model - The model that is accepting the submodel file. Submodel - The model that is being imported. Network Elements - The elements in your drawing pane that make up your model. These are junctions, pipes, valves, tanks, reservoirs, pumps , hydrants, etc. Rules for Importing Submodels 1. Existing elements in the target model will be matched with incoming elements from the submodel using their labels. 2. Incoming submodel input data will override target model data for any element matched by its label. 3. If a submodel element of the same label does not already exist in the target model, it will be created during the submodel import. Element Types Governed by Submodel Rules The rules for importing submodels govern the following element types: Analysis Menu Scenarios Alternatives Calculation Options Components Menu Controls Pump Definitions Unit Demands Zones Patterns Minor Loss Coefficients Pressure Dependent Demand Funtions GPV Headloss Curves ConstituentsValve Characteristics Time Series Field Data Tools Menu User Data Extensions Hyperlinks Example 1 In this example, the Submodel and Target Model have no elements in common (i.e., scenarios, alternatives, calculation options, and network elements do not match). Town 'A' (The Target Model) In the model illustration below, take notice of the labels for the elements outlined in red: Alternatives e.g., "Year 2000 Active Topology" "Plus Two 18in Pipes," "Diameter times 2") Scenarios (e.g., "Year 2000 Conditions," "Plus Two 18in Pipes") Calculation Options (e.g., "Year 2000 Conditions") Network Elements (e.g., Pipes P-90 and P-60, Junctions J-50 and J-40, Pumps, Reservoirs, Tanks, etc.) Town 'B' (The Submodel) In the model illustration below, take notice of the labels for the items outlined in red: Alternatives (e.g., "Model_B_Active Topology") Scenarios (e.g., "Model_B_Average_Day") Calculation Options (e.g., "Model_B") Network Elements (e.g., Pipes B_Pipe-9 and B_Pipe-11, Junctions B_Junc-7 and B_Junc-6, Pumps, Reservoirs, Tanks, etc.) Result of Importing Submodel into Target Model In the illustration below, the target model network elements are visible on the left, and the imported submodel network elements are outlined in red on the right. Since the target model elements have no label names in common with the submodel elements, all of the submodel elements will be created the target model, according to rule 3 above. None of the data in the target model will be overwritten in this case, since there were no matching labels. Observe how the scenarios, alternatives, calculation options, and element labels for all the submodel items have been brought into the target model (see red outlined areas). For example, for the Active Topology alternatives, all of the submodel's (Town 'B') network elements have come in as inactive for the original "Year 2000 Active Topology." The reason is because the newly imported elements did not previously exist in that alternative, so the default attributes are used. In the case of active topology, the default is inactive. So, the newly imported elements are inactive in the "Year 2000 Active Topology" alternative. In the case of the physical alternative, if the submodel's physical alternatives don't match the target model's, the default physical attributes will be used for the newly imported elements, for the physical alternatives that already existed in the target model. So in this example, since the physical alternative in the submodel ("Model_B_Physical") doesn't exist in the target model, it was brought in as a new alternative. So, the pipes from the submodel in the scenarios that use the "Year 2000 Physical" will have 6" diameters and junctions will have zero elevations and so forth. In order to see the original attributes of the submodel elements, the scenario would need to use the "Model_B_Physical" physical alternative. Example 2 In this example, the submodel and target model have some elements in common (i.e., scenarios, calculation options, and network elements J-100, J-210, and P-250). Town 'A' (The Target Model) In the model illustration below, take notice of the labels for the items outlined in red: Alternatives (e.g., "Year 2000 Active Topology" "Plus Two 18in Pipes," "Diameter times 2") Scenarios (e.g., "Year 2000 Conditions," "Plus Two 18in Pipes") Calculation Options (e.g., "Year 2000 Conditions") Network Elements (eg., Pipe "P-250" and Junctions "J-100" , "J-210") Town 'B' (The Submodel) In the model illustration below, take notice of the labels for the items outlined in red: Alternatives (e.g., "Model_B_Active_Topology") Scenarios (e.g., "Year 2000 Conditions") Calculation Options (e.g., "Year 2000 Conditions") Network Elements (eg., Pipe "P-250" and Junctions "J-100" , "J-210") Result of Importing Submodel into Target Model In this model below we have connected the submodel (right) network to the target model network (left) at junctions J-100, J-210, and pipe P-250 (center). This connection occurs because both models shared some of the same junction and pipe labels as import rule 2 states. The submodel data is therefore going to overwrite the existing target model data in any items governed by the rules that are common to both models (illustrated below). You can see that for both the submodel and target model there is also a common scenario name. If any of the properties for this scenario were different the submodel properties for this scenario would overwrite the properties for the target model. Above we see the target model network has all become inactive except for the junctions and the pipe that are shared by both models. This happens because the submodel data is overwriting the scenario data for the 'Year 2000 Conditions' scenario (import rule 2). In the illustration below, Town 'A' Demands and Pipe Diameter before the import are outlined in red Junction Demands Pipe P-250 Diameter J-100 = 19.60 gpm 6 inches J-210 = 72.60 gpm In the illustration below, Town 'B' demands and pipe diameter before the import are outlined in red Junction Demands Pipe P-250 Diameter J-100 = 72.0 gpm 8 inches J-210 = 40.0 gpm In the illustration below, pipe size and junction demands after the import are outlined in red Junction Demands Pipe P-250 Diameter J-100 = 72.0 gpm 8 inches J-210 = 40.0 gpm **If there is a case where the target model and the submodel share elements in common, as in the example above, but the X and Y coordinates differ they will be updated with the X and Y coordinates from the submodel. Example 3 In this example, the submodel and target model share all of the same network elements but, none of the same scenarios, calculation options, or alternatives. Town 'A' (The Target Model) In the model illustration below, take notice of the labels for the items outlined in red: Scenarios Calculations Options Alternatives Average Day Demand Average Day Conditions Average Day Fire Flow Fire Flow Fire Flow Constituent Analysis Constituent Constituent Alternative - 1 Town 'A'_2 (Submodel) In the model illustration below, take notice of the labels for the items outlined in red: Scenarios Calculation Options Alternatives Peak Conditions Peak Condtiions Peak Peak Times 2 Peak Times 2 Result of Importing Submodel into Target Model In the model below we can see the import of the submodel results in all the network elements remaining the same because all these elements had the same labels. Hypothetically, if any of the properties of the network elements were different in the submodel from the target model the properties of the result would contain the values that were contained in the submodel (import rule 2). The significant change that happens in this model, much like in the first example, is that the scenarios, alternatives, and calculation options from the submodel all get added to the target model without overwriting anything. In the model illustration below, take notice of the labels for the items outlined in red: Scenarios Calculation Options Alternatives Average Day Demand Average Day Conditions Average Day Fire Flow Fire Flow Fire Flow Constituent Analysis Constituent Constituent Alternaitve - 1 Peak Conditions Peak Conditions Peak Peak Times 2 Peak Times 2 Steps for completing a Submodel Export/Import 1) Open the model that you want to export the submodel part from. 2) Select the part (or entire) model that you want to export. This can be done in many ways. Three common ways are by using your mouse to draw a box around certain areas, using your mouse to left click and select one element or multiple elements while holding down the shift key, or by holding down the CTRL key + A , which will select all the elements on screen. The default color for selected elements is red. 3) With the elements selected in the display panel go to File > Export > Submodel. Name and save your model to a location that you will remember. 4) Now open your target model and after it load go to File > Import > Submodel. Note: if you would like to import the entire model and not a subsection of the model, only step 4 is required. Meaning, in the target model, simply go to File > Import > Submodel, then select the .wtg.mdb file associated with the submodel you would like to import. Troubleshooting If you know you imported the model but don't see anything or are missing part of the model on in your display area. Answer: Go to Tools > Options and see if the option on the Global tab for "Display Inactive Topology" is checked. Also notice the color the inactive topology is set to. If all or part of the model you imported is gray Answer: Your model has likely imported correctly but, all or part of it is currently inactive. If you want it to appear as an "active" status element the active scenario you have to use the active topology tool (Tools > Active Topology Selection) or go into the active topology alternative and change the status of the inactive elements. The reason this happens is because the active topology alternative in the submodel did not match the target model. So, the default status of inactive is used. If you do not want to manually change this in the resultant model, you will need to first go back to the target model and change the labels and structure of the active topology alternatives, so that they match between the models. The attributes/data from the submodel were lost Answer: If the properties of the submodel elements appear to use the default values (such as 6" for all diameters, zero elevation, etc), most likely the physical alternative(s) in your submodel did not match the physical alternatives in the target model. For example if a scenario and physical alternative exist in the base model but not in the submodel, any new elements imported from the submodel will use default values for physical properties in that scenario in the base model. You will either need to correct this manually, or go back to the target model and change the labels and structure of the alternatives so they match exactly to the target's What if models have same labels? Answer: If models have same labels such as P-1 in Project A and P-1 in Project B as well, then the tool from the link below can be used to prefix the Labels before importing. Once the import process is done, the prefixed label can be removed too. http://communities.bentley.com/other/old_site_member_blogs/peer_blogs/b/akshayas_blog/archive/2013/07/11/update-labels-of-a-hydraulic-model-using-waterobjects-net.aspx OR You can use the relabel function in the flextables to relabel some elements. The wiki for how to do that can be found here: See Also Product TechNotes and FAQs Haestad Methods Product Tech Notes And FAQs Hydraulics and Hydrology Forum External Links Bentley SELECTservices Bentley LEARN Server
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Wiki Page: "Error 1406" when installing
Product(s): WaterGEMS, WaterCAD, HAMMER, SewerGEMS, SewerCAD, StormCAD, CivilStorm, PondPack Version(s): 08.11.XX.XX Area: Installation Problem "Error 1406" appears when attempting to install. [Problem ID#: 35484] Solution This error typically indicates a problem with permissions. First, ensure you are logged in with administrative permissions. Also, temporarily disable any security/antivirus applications, such as McAffee. [Solution ID#: 500000062232] See Also Generating a log file for installation problem troubleshooting
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Wiki Page: Why does the profile for the system appear to be at odds with the results for the capacity?
Applies To Product(s): StormCAD, SewerGEMS, SewerCAD, CivilStorm Version(s): 10.00.xx.xx, 08.11.xx.xx Area: Calculations Original Author: Scott Kampa, Bentley Technical Support Group Problem Description Why does the profile for the system appear to be at odds with the results for the capacity? For example, the profile does not show a conduit as being full, but the capacity results indicate that it is. For example, "Capacity (Full Flow)" = 50 ft^3/s and flow through a conduit is 60 ft^3/s, but the hydraulic grade is below the top of the conduit in profile view. The opposite symptom can also occur, where the profile shows the conduit as being full/surcharged yet the flow through it is less than the reported Full Flow Capacity. Solution In short, it may be that the water in the conduit has not had a chance to reach a normal depth condition yet, in which case the result you see in the profile view should be considered, rather than the capacity result. The full capacity is the flow through the conduit if normal depth were equal to the top of the conduit. Using Manning's equation as shown below, the program calculates the "Capacity (Full Flow)" results of a conduit. The "Capacity (Full Full)" results are based on the assumption that flow through the conduit is absolutely at a normal flow condition and the normal depth equals the rise of the conduit (for circular conduit the rise = diameter). Q = k/n*A*R^(2/3)*S^0.5 [Manning's Equation] At normal flow: • The water depth, flow area, flow, and velocity distribution at all cross-section and throughout the entire length of conduit remains constant. • The Energy Grade Line (EGL), Hydraulic Grade Line (HGL) and the Channel Slope are parallel. • The velocity/depth ratio is constant. • There is no acceleration or deceleration of the moving mass. You can verify this by using a simple Manning's equation normal depth calculator, such as Bentley FlowMaster. However, in SewerGEMS, CivilStorm, StormCAD, and SewerCAD, water does not always flow at normal flow; it computes a varied flow profile . As a result, the HGL slope can change over the length of the conduit. Because of this, the actual depth in the conduit can be different than normal depth and the "full flow capacity" results may not be a good comparison, especially with short conduits that may have otherwise achieved a normal depth condition if extended further. In the case of a conduit that does not appear full in profile, but has a flow that is greater than the capacity, then the gradually varying flow results that the model computes are telling you that the conduit is not flowing full, but the normal-depth based capacity results indicate that the conduit is full. The gradually varying flow results as seen in the profile should be considered in this case since they are a truer representation of what would happen in the real system, rather than the capacity result, which makes the assumption of normal depth. In this example case, to help visualize this in the actual model, try increasing the length of the conduit in question by 10 times the original length and then look at the profile of that conduit. You will notice that the upstream end of the conduit will extend above the top of the conduit as it tries to find a normal depth condition. If not, increase the length of conduit again. What this means is the initial conduit length is not long enough for the water surface to settle on the surcharge condition even though the flow exceeds the maximum capacity and therefore the HGL in the profile is not above the conduit crest elevation. If you see a discrepancy between the profile and the capacity results, that likely means that the profiles are likely not flowing at normal depth. In such a case, you may want to look at the " Depth (Average End)/Rise " (called "Depth/Rise" in the latest version) result field instead. This is the middle depth of the conduit divided by the conduit diameter or rise, which provides a better gauge of how full the conduit is at the midpoint when normal depth conditions are not met. In other words, it shows the actual calculated depth in the conduit in the gradually varying flow condition - the truer result that the model predicts and should be considered over the capacity result. A note on automated design Automated design is also based on these same capacity concepts. By default, it will attempt to pick a pipe size whose full capacity is greater than the flow through the pipe. It seems logical to ask that the pipe size instead be based on the actual calculated depth in the pipe, but there are a few reasons why this would not work well. The depth of flow in the pipe based on the gradually varied flow calculations, can be influenced by adjacent pipe hydraulics. For example consider an outfall pipe that discharges below the surface of a body of water. The connected conduit will be at least partially surcharged even when the flow through it is less than the normal-depth based capacity. If the design were instead based on calculated depth, it may choose a very large pipe size that may not be reasonable. Example #1 - Flowing above full capacity yet not surcharged in profile Observe the following example conduit, whose "Capacity (Full Flow)" is 50 ft^3/s. This means that if normal depth were equal to the top of this conduit, the flow through it would be 50 ft^3/s. In this case, the flow through the conduit is 60 ft^3/s, yet the conduit is not surcharged. Now observe what happens if we extend this conduit upstream. Notice that the hydraulic grade eventually reaches the top of the conduit, indicating the surcharge condition. This surcharging is not seen over the entire length of the conduit because there is a transition to a steeper downstream conduit. Example #2 - Flowing below full capacity yet surcharged in profile In this example we have a conduit with capacity of 29 CFS and a calculated flow through the conduit of 21 CFS, however, the profile shows that conduit is surcharged. The reason is because there is a tailwater / backwater effect from other flow entering downstream and causing a backup. Since the network is solved as a whole and the downstream HGL is essentially communicated upstream during the backwater analysis (SewerCAD and StormCAD solvers) or dynamic wave calculations (SewerGEMS and CivilStorm Implicit or Explicit solvers), the conduit in question becomes surcharged. The full capacity figure of 29 CFS is based on a normal depth assumption, but a normal depth condition is not experienced in this case, so the capacity figure is at odds with the profile/HGL.
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Wiki Page: Pond Results "Flow (outlet)" vs "Flow (Total Out)"
Product(s): PondPack, SewerGEMS, CivilStorm Version(s): 08.11.XX.XX Area: Output and Reporting Problem What is the difference between the "Flow (Outlet)" and "Flow (Total Out)" results fields for a pond? [Problem ID#: 39296] Solution "Flow (Outlet)" is the flow out of the pond via pond outlets, not including infiltration. "Flow (Total Out)" is the total flow leaving the pond, which includes infiltration. [Solution ID#: 500000065904] See Also How can I find the total volume from a hydrograph? Velocity through outlet structure
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File: TCV Closure Example model
This illustrates the use of the TCV node element in Bentley HAMMER to model valve closure.
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Wiki Page: Modeling Reference - Valves
Applies To Product(s): HAMMER, WaterGEMS, WaterCAD Version(s): V8i, CONNECT Edition Area: Modeling Original Author: Jesse Dringoli, Bentley Technical Support Group Overview This technote explains how various types of valves work and their typical application in HAMMER and in WaterGEM / WaterCAD. It also provides an example model file for demonstration purposes. Primary Valve Elements The main "valves" icon on the layout toolbar offers several generic valves: GPV, TCV, FCV, PRV, PSV and PBV. These are sometimes collectively referred to as "valves of various types" in older versions of HAMMER. These valve elements serve various purposes and are frequently used in steady state or Extended Period hydraulic models. They can generally be categorized as flow control. For example, the GPV defines a curve of flow versus headloss, the FCV (Flow Control Valve) controls flow to a set point and the PRV (Pressure Reducing Valve) controls the downstream pressure to be below a set point. The important thing to understand about dynamic valves like FCVs, PSVs and PRVs is that their controlling effects (pressure reduction, flow control, etc) only apply to the initial conditions calculation (steady state or EPS). For a given steady state or EPS timestep, a specific headloss occurs across the valve. For example, in order for the PSV element to sustain upstream pressure, a specific headloss occurs through the valve, such that in order to balance energy across the network, the upstream hydraulic grade ends up being higher than the PSV set point. During the transient simulation, a discharge coefficient is calculated based on that valve's headloss during the initial conditions timestep. Note: the following equation is used to convert between headloss coefficient and discharge coefficient: H = 39.693 * D^4/Cv^2 Where: D = Diameter (ft), H = Headloss coefficient (K), Cv = discharge coefficient (cfs/ftH20^0.5) It can be re-written as: Cv = ((39.693 * D^4) / H)^0.5 As the transient simulation progresses and the system conditions change, these valves will not automatically react, like they do during the initial conditions. Meaning, if the transient conditions cause a higher flow through a FCV, it will not automatically throttle (change its headloss) to react accordingly. The reason is because HAMMER assumes that these valves cannot react fast enough during the transient simulation. So, they will stay in a fixed position based on the aforementioned discharge coefficient from the initial conditions. However, the user can manually open and close these valves during the transient simulation by using the Operating Rule. The operating rule is an attribute of the valve, found under the "Transient (Operational)" section of the properties. It allows you to define a pattern of Time versus Relative closure, to be using during the transient simulation. Note: PRVs are currently an exception to this, as they have the ability to modulate (throttle automatically to meet a setpoint) during the transient simulation. See related article: Using Modulating PRVs For example, if you have a gate valve that is fully open in the initial conditions and you want it to fully close during the transient simulation, you could define your operating rule with a starting relative closure of 0% and pattern that rises to 100% at some point. You would then select that in the valve's properties, under the "Operating Rule" field. You can analyze the effect of various closure patterns either by manually changing the operating rule and re-running the simulation or by creating multiple scenarios, computing a batch run in the scenario manager and then individually examining the transient results. Note: The operating rule designation is stored in the "Transient" alternative. Generally the transient surge will be more severe for a faster closure. So, typically the last bit of closure should occur slowly. For example, the valve may close quickly between 0% and 95% closure, then slowly close for the last 5%. However, you may want to analyze the worst case scenario where the valve is closed too quickly. The speed of closure can easily be reflected in your Operating rule pattern. Note: Do not confuse the Operating Rule with the "Pattern (Valve Settings)" or "Pattern (relative closure)". The latter two fields may be found under the "physical" section of the valve's properties and are used to establish a manual closure pattern for the valve during the initial conditions (EPS) only. For general valve closure purposes such as gate valves, isolation valves, etc, it is recommended that you use the TCV valve type (throttle control valve). This valve represents a standard headloss or discharge coefficient during the initial conditions. So, in the above example of an initially open valve, you would specify the loss coefficient representing the losses through the fully open valve. Other Valve Types Valve with Linear Area Change - The "Valve with Linear Area Change" element represents a simplified valve that either closes linearly (with respect to area) or acts as a check valve that stays closed upon reverse flow. The user only specifies a time to close, so no delay can be incorporated with the closure. Meaning, it starts closing as soon as the transient simulation begins. See more here: Modeling Reference - Valve With Linear Area Change Pump valves - The pump element has a built-in valve, that can either operate as a check valve (when the "Pump Valve Type" is set to "check valve") or a linearly closing valve (with the "Pump Valve Type" set to "Control Valve"). The Control valve will either open or close over a given duration, depending on the initial status of the pump (on or off). See also: Modeling a pump that has neither a check valve nor a control valve Check valves - a check valve can be simulated in a pipe, as a separate node element, and built into a pump. These close upon reverse flow. A slow closing operation can be modeled with the check valve node element. More on this here: Modeling Reference - Check Valves Isolation valve - this element can be associated with the pipe, so it has the benefit of not adding an extra pipe from a split. However, the operation of this type of valve cannot be simulated during a transient simulation. Meaning, it can only be used to set the initial status of the related pipe to open or closed. If you need to control an isolation valve, use the TCV element instead. Initially Partially Closed Valves The TCV also has the ability to model the opening/closing of a valve that is initially partially closed. This is done by way of the "valve characteristics curve" coefficient type and "Valve Type". Normally, the discharge coefficient that the program computes based on what the valve is doing during the initial conditions is interpretted by HAMMER as the fully open position. For example, if you use a GPV, the headloss calculated through it in the initial conditions is always interpretted as a relative closure of 0%, even though in reality, it may be partially closed. This can cause confusion when defining the operating rule. However, with the valve characteristics curve coefficient type for a TCV, the user can define the relationship of discharge coefficient versus relative closure; therefore, a partially closed valve can be properly modeled. Detailed instructions on how to do this are beyond the scope of this technote. For more information, please see Modeling An Initially Partially Closed Valve Custom Valve Characteristics By default, several standard valve types are available, in the "valve type" field (such as butterfly, globe, needle). This essentially defines the discharge coefficient that HAMMER uses for various values of "relative closure" in the operating rule. For example, some valves may have a sharp reduction in area as they start to close (stroke) and then a slower reduction in area just before they are fully closed. Meaning, a value of 90% closure in your operating rule might not necessarily mean the valve's open area is 10% of the original area. The user can also define a user defined table of relative closure versus relative discharge coefficient, by selecting "user defined" as the valve type. This exposes the "Valve Characteristics" attribute, which is where you would enter the table of relative closure versus relative discharge coefficient to define the characteristics of your valve. The relative discharge coefficient values are relative to the value entered for "Discharge Coefficient (fully open)". Valve Characteristic Curves Valve characterisic cuves for standard types are based on published data (Fok, 1987). The curves have the functional form: 1 – Yk ... where needle valves have k = 2.0; circular gate valves, k = 1.35; and globe valves k = 1.0; or (1 – Y )k ... where for ball valves, k = 1.35; and butterfly valves, k = 1.85. More information can be found at the following paper: Fok, A.T.K., “A Contribution to the Analysis of Energy Losses in Transient Pipe Flow”, Ph.D. Thesis, University of Ottawa, 1987. Note: most valve manufacturers can provide the discharge coefficient(s) Note: When modeling a valve whose initial status is "inactive", ensure that you've entered a value for the "minor loss coefficient". When computing initial conditions, the "minor loss coefficient" is used to compute headloss through the fully open (inactive) valve. This headloss is important since it is used to define the relationship between head loss and discharge as the valve closes. Example Model In the latest version of HAMMER, this example model can be found in the "Samples" folder within the installation folder and is called "Valve_Closure_Example.wtg". For older versions that do not have this, you can download a version of it here: Click to Download Note : the above model is for example purposes only. It can be opened in version 08.11.00.30 and above and you can find additional information under File > Project Properties. Also, you must be signed in to Bentley Communities or the link will not work . Reference Advanced Water Distribution Modeling and Management - Walski, 2007 See Also Protective Equipment FAQ Modeling An Initially Partially Closed Valve Modeling Reference - Valve With Linear Area Change Using Modulating PRVs General HAMMER V8i FAQ
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Wiki Page: User Notification "The Output increment is not an equal interval of the simulation duration..."
Product(s): PondPack Version(s): 08.11.XX.XX Area: Output and Reporting Problem User encounters a user notification stating that the simulation duration was adjusted due to the output increment not being an equal interval of the duration entered. However, the output increment is in fact an equal interval. For example: "The output increment (0.002 hours) is not an equal interval of the simulation duration (30.000 hours). The actual simulation duration is 29.999 hours." [Problem ID#: 39293] Solution This message is just informational. The reason for this is because the output increment is converted to seconds, then rounded to the nearest second. So in the above example, the output increment was entered as 7.2 seconds (0.002 hours), but PondPack uses 7.0 seconds. Since 7.0 is not an equal interval of the user-entered simulation duration of 108,000 seconds (30 hours), the total simulation duration is rounded and adjusted accordingly. [Solution ID#: 500000065901] See Also PondPack TechNotes and FAQs
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Wiki Page: PondPack User Notification "The X structure with the id 'Y' is out of range..."
Product(s): PondPack Version(s): 08.11.01.56 Area: Calculations Problem When computing an outlet structure with a downstream channel for tailwater, the following error occurs: "The X structure with the id 'Y' is out of range. If using a Downstream Channel tailwater type, make sure the channel has enough capacity." [Problem ID#: 43780] Solution There are two things to check: 1) Make sure that for the range of flows through the outlet (you can check using free outfall for tailwater) the corresponding tailwater is less than the corresponding headwater. Basically make sure the capacity of the downstream channel is greater than the outlet structure. 2) If using an irregular channel cross section for the downstream channel, make sure the bottom elevation of the irregular cross section is higher than the lowest elevation in the outlet structure (for example culvert downstream invert) [Solution ID#: 500000070205] See Also PondPack TechNotes and FAQs
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