Product(s): WaterGEMS, SewerGEMS, CivilStorm, StormCAD, SewerCAD, HAMMER, WaterCAD Version(s): 10.01.XX.XX Area: Data Input Problem Can interactive web map sources be used as background layers? Solution Starting with CONNECT Edition Update 1 (10.01.XX.XX), you can connect to Bing Maps to bring in aerial and road maps automatically. This is done from the Background Layers manager. For more information, see the related help topic on Bing Maps. For versions below 10.01.XX.XX, this can only be done on the platform products such as Microstation, ArcMap, or AutoCAD: ArcMap To use an interactive map as a background layer in ArcMap go to File > "Add Data" > "Add Data from ArcGIS Online" and sign in to the website if necessary. Microstation In Microstation this can be done using the steps in this wiki AutoCAD There is information found on the internet that has instructions for how to work with interactive map data. See Also How do I import a Google Earth image so it lines up with my model? How do I create a .KMZ Google Earth file out of my model? [Help Topic] Using a Google Earth View as a Background Layer to Draw a Model
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Wiki Page: Using Google Earth, Bing Maps, or other interactive data sources as a background layer
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Wiki Page: Adding Google Earth or Bing Maps aerial or road maps as a background layer
Applies To Product(s): WaterGEMS, SewerGEMS, CivilStorm, StormCAD, StormCAD, HAMMER, WaterCAD Version(s): 08.11.XX.XX and 10.XX.XX.XX Area: Other Original Author: Mark Pachlhofer, Bentley Technical Support Group Problem Description How do I import a Google Earth or Bing Maps image (road map or aerial image) so it lines up with my model? Solution - Bing Maps Starting with the CONNECT Edition Update 1 release (10.01.XX.XX), Bing Maps can be added directly from the background layers manager, with the ability to align to the model with up to three points of reference. See the related Help topic. Solution - Google Earth *Please note that this solution was created based on the Google Earth application that was current at the time of the making of the video. It may not be the exact solution for future versions of Google Earth. Note: you may need to watch this video in full screen mode in order to see it clearly. (Please visit the site to view this video) See Also [Help Topic] Using a Google Earth View as a Background Layer to Draw a Model How do I create a .KMZ Google Earth file out of my model?
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Forum Post: RE: Importing a file from google earth to sewergems
Hello Augustine, I have moved your post from the Academic forum to the Haestad | Hydraulics and Hydrology forum. What version of SewerGEMS are you using? See the following wiki articles: Adding Google Earth or Bing Maps aerial or road maps as a background layer Using Google Earth, Bing Maps, or other interactive data sources as a background layer Starting with the latest release (10.01.00.70), the easiest way would be to connect to Bing Maps in the background layer manager. The above articles also explain how to use Google Earth.
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Wiki Page: Controls not being followed
Applies To Product(s): WaterGEMS, WaterCAD Version(s): 08.11.xx.xx, 10.xx.xx.xx Area: Modeling Original Author: Bentley Technical Support Group Problem My pumps (or other element such as a valve) do not appear to be following their controls. For example a pump should stay off but it stays on. Solution There are a few things that should be checked to ensure that the controls are set up properly: 1) Check to make sure that the controls in question are enabled in the Operational Alternative. First, with the scenario in question active, navigate to Analysis > Alternatives, then open the Operational alternative assigned to that scenario. Note the control set, click the ellipsis button (...), then make sure that the controls are present in that control set. If they are not, add them. 2) If you are computing a steady state simulation, check the calculation option set assigned to your scenario and check if the "Use simple controls in steady state?" is set to True. If it is, ensure that the controls in question are marked as Simple control (as opposed to logical, which are only supported in Extended Period Simulations - EPS). There are also some types of controls that are not supported in steady state (you'll see User Notification for these) in which case you can simply manually set the initial status of the action element based on the condition in that steady state. 3) Make sure you're accounting for all controls currently set on the element in question. For example if the problem is with a pump, open the pump's properties and click the ellipsis button next to the "Controls" "Collection". This will display all the controls currently being used on that element. You may find that there are multiple controls and/or conditions that control the element in question. 4) Use graphs to view the conditions and actions. For example, if the control is based on tank hydraulic grade and pump status, select both the tank and the pump, Right-click > Graph, then select hydraulic grade for the tank and flow for the pump. From here, you can get a good visual of the condition and the action, to double-check if the action is occurring when the condition warrants. 5) For tank-based controls, check to make sure the correct values are used based on the tank condition's "storage attribute". If "hydraulic grade" is selected, the values used should be hydraulic grades (sea level datum) whereas if "level" is used, the values are distances above the tank bottom. 6) Check the operator on any controls that include tanks. Controls that exclusively use an equals (=) sign can skip over the value entered in the control. For instance, if a pump is set to turn on when the tank level is less than 5 feet and you enter the condition of the control as "IF Tank Level = 5 feet THEN..." the control will only be triggered if the tank level is exactly 5.00 feet. If it is a little less or a little more, it will not. It is better to use the greater than or less than operator for tank elevations and levels. This will assure that the condition is met. 7) Check to make sure that you are seeing all time steps in your graph. In the calculation options, set "Reporting Time Step" to "All", to ensure that intermediate timesteps are not being skipped over on graphs. 8) Make sure the model is balanced during the time steps when the control should be operating. In the Calculation Summary, you will see a red icon next to a trial if it is not balanced, plus a message in the tabs at the bottom and in the User Notification window. An unbalanced network indicates instability in the calculation which needs to be resolved before the results can be trusted. See item 6 below. 9) If you believe a tank should be filling yet the model shows it draining (or vice versa) because of pump controls that appear to be operating correctly, try tracing the HGL using profiles. For example a tank may still be filling when upstream pumps turn off, because of a high HGL from elsewhere in the system, such as another pump/tank, or from an inflow (negative demands). Select a timestep when this occurs, and follow the flow arrows starting at the tank in question, checking the HGL along the way. You can also use tracing tools in Network Navigator . 10) If the status of the action element still doesn't appear to be correct based on the controls, try checking the Intra-Trial Status Messages tab in the Calculation Summary (available in SELECTSeries 5 and higher, build 08.11.05.61). This will display status changes that occur during a trial. If you see certain elements switching status in a given time step, it's an indication that there is some instability causing the status to oscillate. For example if you have a pump turn on and off based on pressure at a junction, it's possible that the act of turning on the pump may instantly trigger the pump to turn back off based on the pressure set points. In this case, the time step may balance on a condition that may appear to be at odds with the control. In this case, you will notice the pump changing status in the Intra-Trial Status Messages tab, when clicking on the time step in question. Another common example would be dynamic valves like PRVs and PSVs. For example a PRV becoming active may cause another PRV to become active, which then causes the first one to become open, and so on. If this occurs, you'll see the PRVs show up multiple times in the intra-trial status messages tab. See Also What is the difference between a Simple Control and a Logical Control?
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Forum Post: RE: Error creating profile due to a "gutter being part of the path" problem - SewerCAD CONNECT
Hello AHQ, I was able to reproduce this issue in a sample file in SewerCAD 10.00.00.45, but not in the recently released 10.01.00.70 (CONNECT Edition Update 1). Are you able to upgrade? You can read more about the release here: Forum | Blog .
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Wiki Page: Troubleshooting negative pressures at pumps, junctions, & other node elements
Applies To Product(s): WaterGEMS, SewerCAD, HAMMER, WaterCAD Version(s): 08.11.XX.XX, 10.XX.XX.XX Area: Modeling Original Author: Dan Iannicelli , Mark Pachlhofer, and Jesse Dringoli, Bentley Technical Support Group Discussion: A negative pressure means that the calculated hydraulic grade is below the physical elevation of the element. You should closely examine your node elevations and boundary conditions (reservoir/tank hydraulic grades) to make sure they are correct. It is common for this to occur on the suction side of the pump, due to the elevation that you entered for the nearby reservoir. If the pump is off, then it is likely that the reservoir elevation is set to be lower than the pump elevation. Creating a profile of the area in question (physical elevations and hydraulic grades) should give you a good visual idea of what is going on. Note that negative pressures will not prevent the model from computing - the messages that you get about these are just informational. WaterCAD/GEMS still assumes that the pipes are pressurized and no vapor pockets will form. It basically just computes the hydraulic grade based on the system conditions and other data input, and then reports the pressure as the difference in head between that and the physical elevation. If the negative pressures occur at high points in the system, you probably would have an air valve at that point so you can fill the pipeline. However, once the pipeline is running, only those air valves that would have a pressure below 0 need to be modeled as active air valves (Treat as Junction? = False). The others can be set to 'True'. How can I troubleshoot the cause of negative pressure in my model? Start by tracing the negative pressure upstream to the supply of the flow. If the supply is from a pump examine the pump's output flow and pump head to see where it's running during the time of the negative pressure. Next check the pumps definition (pump curve) and see where that point is located on the curve. It could be the pump is too small to deliver the required amount of flow or head the system demands. If the supply is from a reservoir or tank make sure the hydraulic grade (elevation) is high enough to supply the downstream demands and overcome the head losses in the pipes. After you've found the supply of the flow, and if the above information didn't help, follow the flow downstream and check each node until you locate where the negative pressure first starts. Once the first negative pressure is found determining the cause should be a matter of looking at the data entry and results in the element just upstream of it. What does it mean when a node reports a negative pressure? A negative pressure occurs when the hydraulic grade is below the physical elevation of a node. If WaterCAD/GEMS says the pressures will be negative, then in all likelyhood you will have problems. Assuming all data input has been checked, there are usually two general causes of negative pressure: 1. Trying to serve a customer at too high of an elevation. This will show up as low/negative pressure at any demand. You need to increase pump head or adjust pressure zone boundaries. 2. Some restriction in the system. This will show up as good pressure during low demand and poor pressure at high demand. You need to look at the model results and see if the pipes are too small causing excess head loss or the pumps are inadequate such that they are running far off to the right of the curve. You need to upsize the pipes or pumps accordingly. You should also check your demands for errors. Since your demands are likely based on historic averages, a significant decrease in pressure may skew the results, since the demands would likely be decreased in that condition. You may consider using pressure dependent demands or flow emitters. You may also consider conducting a transient analysis using Bentley HAMMER, if the problem occurs at a transmission main. What does the user notification, "Pressures below the lowest physically possible pressure in system at one or more time steps. Set up Alerts for details." mean? As of WaterCAD/WaterGEMS Select Series 6, this is a new user notification that was designed because sometimes small negative pressures aren't that bad. This user notification helps to reduce the number of negative pressure user notifications that used to be generated for each node where it occurred. If you'd still like to see those user notifications you can set up custom alerts described in the wiki link below: By double clicking on the user notification the properties window for the calculation options will open and you can adjust the minimum possible pressure (default value -14) if desired. Changing this will change the pressure at which the user notification will be generated. What are the best ways to visually locate negative pressures? 1. By creating an annotation based on pressures for your node elements. 2. By creating color coding based on pressures for your node elements. 3. Using a network navigator (View > Network Navigator) query for negative pressures (see the screen shot below) 4. Creating a custom alert for negative pressures. 5. By using the flextable to view the pressures sorted descending to ascending. Why do I get a negative pressure at a high point in my system? Shouldn't the pump add enough head to push the water over the hill? By default, pumps only consider the boundary conditions (reservoirs and tank elevations) in your system. So, the pump will add enough head to lift the water to the downstream known hydraulic grade. It does not consider junction elevations in between. If you are using WaterCAD or WaterGEMS V8i, you should add an Air Valve element at the high point to properly model this situation. By placing an air valve at the high point, the pump sees the air valve elevation as its downstream boundary condition for instances in which pressure would have otherwise been negative at the high point. For any air valve that is expected to be open in this way, ensure that you select "false" for the "Treat air valve as junction?" attribute. For more on this, see this technote . Another alternative to resolving negative pressures to take into consideration is installing a PSV at the downstream end of the system with a hydraulic grade equal to the highest point in the system. What will I need to do if I have negative pressures at high point in my system that does not have air valves installed? If you get a negative pressure at a high point that means the system is a siphon at that location. It is best to put an active air valve at that point (Treat as Junction? = False). If I find that pressure at any point in my system drops below vapor pressure what do I need to do? If the pressure drops below the vapor pressure, the siphon will not work. You definitely need to install an active air valve there (Treat as Junction? = False). This will also help provide protection against a vapor pocket collapse that would cause a transient to occur. Why do I get a user notification about negative pressure at a pump? This commonly occurs in cases where the user models the pump station (or connection to an existing system) using a reservoir and pump, with short pipe between them. Typically, the same elevation is used for both the pump and reservoir nodes. Since the reservoir elevation defines the boundary hydraulic grade and since there will always be some amount of headloss through a pipe, this means that the hydraulic grade at the pump node location will be slightly below the physical elevation. The suction pressure of the pump is derived from the difference between the hydraulic grade and the physical elevation, so that is why the pressure ends up being negative. You can simply ignore this informational message, but if you'd like to remove it, the solution is to simply raise the elevation of the reservoir by a small amount. Make sure the pipe has a very large diameter and smooth roughness coefficient, too (to minimize headlosses.) If the upstream hydraulic grade or reservoir elevation is correct, then this negative pressure message is accurate. To better understand what is happening, create a profile of the hydraulic grade and physical elevation for this segment of piping - you will see that the hydraulic grade is below the pump elevation. If this is an existing system, you may need to check your NPSH to ensure that cavitation will not occur at the pump. You can also investigate ways to increase the hydraulic grade upstream of the pump. Also consider: 1) Margin of error - the model results may not exactly match real field conditions. You may have made an assumption for certain model parameters that may not necessarily reflect the real system, and if they are skewed a certain way, it could result in even lower pressures than predicted in the hydraulic model - unless you have calibrated the model. 2) Demand conditions - what demand conditions were you looking at? (average day demand, peak hour, etc) Higher demand conditions would result in lower pump suction pressure. 3) You should also consider transient conditions. For example upon pump startup, if the pump starts too quickly, the resulting transient may cause a "downsurge" wave on the suction side, lowering the pressure further. If it drops below the vapor pressure limit of water, a vapor pocket can form and cause subsequent damaging effects when it collapses.
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Forum Post: RE: Error creating profile due to a "gutter being part of the path" problem - SewerCAD CONNECT
I see; I am using the 10.00.00.45. Yes I can upgrade. Do I need to also apply the patch that was sent for the "model reading old result files" issue or no need?
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Forum Post: RE: Error creating profile due to a "gutter being part of the path" problem - SewerCAD CONNECT
Hello AHQ, Is this patch for 10.01.00.70 version? If yes, then there is no any harm in applying the patch.
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Forum Post: RE: Error creating profile due to a "gutter being part of the path" problem - SewerCAD CONNECT
Hi, I'm not clear on that and hence asking. The patch file name has 10.0.0.45 in it but the problem that this patch fixes was also reproduced by Jesse in the 10.01.00.70 prior to releasing the patch so wondering whether the same patch also fixes the problem in the new release. that relates to this post communities.bentley.com/.../civil-storm-view-catchments
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Forum Post: RE: Error creating profile due to a "gutter being part of the path" problem - SewerCAD CONNECT
Hello AHQ, The patch for CivilStorm 10.01.00.70 is different, each version has its own patch which is applicable to that version only. I will send you patch for CivilStorm 10.01.00.70 through the open service request - 7000697456.
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Forum Post: RE: Error creating profile due to a "gutter being part of the path" problem - SewerCAD CONNECT
Thanks. I understand the same patch will also work for installs of StormCAD and SewerCAD of that same version.
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Forum Post: RE: Error creating profile due to a "gutter being part of the path" problem - SewerCAD CONNECT
Yes, the 10.01.00.70 patch applies to SewerGEMS, CivilStorm, StormCAD and SewerCAD 10.01.00.70.
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Forum Post: RE: CONNECT Edition Update 1 release of SewerGEMS, CivilStorm, SewerCAD, and StormCAD
Hey! This is exciting. Looking forward to seeing some more documentation on some of these new features and getting to try them out. Thanks for all your work!
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Forum Post: RE: CONNECT Edition Update 1 release of SewerGEMS, CivilStorm, SewerCAD, and StormCAD
Thanks for the feedback, David. Yes, more details to come soon. We'll plan to post a reply on this thread. You can also install the upgrade and take a look at the in-product documentation.
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Forum Post: RE: SewerGEM - How do i stop a pump from operating if the receiving pond reaches a level in the model.
Hello Boon, Thanks for sending the model. This seems to be related to the AND statement on one of the rules. If you model the AND portion to a new line, the model will start to compute. The following is an example of what you would need to do: IF PUMP xxx STATUS = OFF AND PUMP yyy STATUS= OFF THEN PUMP zzz STATUS = OFF Regards, Scott
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Wiki Page: Using SWMM Control Sets in SewerGEMS and CivilStorm
Product(s): SewerGEMS, Bentley CivilStorm Version(s): 08.11.xx.xx, 10.xx.xx.xx Area: Modeling Problem Can SWMM Control Sets be used in Bentley's storm and sewer products? How is the data inputted and utilized? Solution SWMM Control Sets allow a SewerGEMS or CivilStorm user to control the behavior of elements based on the condition in some other element using control rules set based on the SWMM program. These control rules are based on the syntax rules presented below and are used only by the Explicit (SWMM) solver. SWMM Control Sets can be used to turn pumps on and off. They can also be used to adjust the weir height and orifice opening for conduit control structures. Additional information on these can be found in the SewerGEMS and CivilStorm Help documentation. The following screenshot shows the objects that can be used in SWMM Control Sets: Node (depth, head, inflow), link (flow, depth), pump flow, and simulation time are typically used in the condition part of the Control Set. The pump status and orifice and weir settings are used in the action statement. The formatting of this statement is similar to the logical control statement that users of WaterGEMS, WaterCAD, and SewerCAD may be familiar with: IF condition THEN action ELSE action2. Priorities can also be added that will make it so a given control takes precedence over another control. Creating Control Sets As SWMM Control Sets are used with pumps or control structures on conduits, these elements will need to be present in the model. Go to Components > SWMM Extensions > Control Sets to open the SWMM Control Sets dialog. This is where you can create and edit your control sets. To create a new control set, click the New button in the upper left. The Control Editor Pane on the right side of the dialog allows you to define SWMM controls. Each control rule is a series of statements of the form: RULE ruleID IF condition_1 AND condition_2 OR condition_3 AND condition_4 Etc. THEN action_1 AND action_2 Etc. ELSE action_3 AND action_4 Etc. PRIORITY value where keywords are shown in all caps, ruleID is an ID label assigned to the rule, condition_n is a Condition Clause, action_n is an Action Clause, and value is a priority value (e.g., a number from 1 to 5). NOTE : Only the RULE, IF and THEN portions of a rule are required; the other portions are optional. Blank lines between clauses are permitted and any text to the right of a semicolon is considered a comment. Expected Units for control sets are as follows: Flow: cfs; Length: feet; Time: hours. No units are actually entered in the control set. For example, suppose you wanted to create a control where a weir setting changes based on the flow on a given conduit. The control would be formatted like this: RULE 1A IF LINK CO-1 FLOW > 10 THEN WEIR W1 SETTING = 0.5 In this case, you would enter "LINK" before the conduit label so that the control knows what type of element it is. In the action statemnt (THEN), you include the element type as well as a label. In the example above the label is "W1". This is applied in the Conduit Control Structures dialog, where the information for the control structure is inputted (Components > Conduit Control Structures). The next step for using SWMM Control Sets is to open the calculation option properties. Set the property field Apply SWMM Control Set to "True." For the property SWMM Control Set, click the pulldown menu and select the name. Keep in mind that your SWMM Control Set will typically have more than one entry. For instance, you will have controls for the pump turning and off. For conduit control structures, you would have different weir or orifice settings for different simulation times or flow values. Examples The following are examples of control rules that can be used in SWMM Control Sets: Simple time-based pump control RULE R1 IF SIMULATION TIME > 8 THEN PUMP 12 STATUS = ON ELSE PUMP 12 STATUS = OFF ; Multi-condition orifice gate control RULE R2A IF NODE 23 DEPTH > 12 AND LINK 165 FLOW > 100 THEN ORIFICE R55 SETTING = 0.5 RULE R2B IF NODE 23 DEPTH > 12 AND LINK 165 FLOW > 200 THEN ORIFICE R55 SETTING = 1.0 RULE R2C IF NODE 23 DEPTH 5 THEN PUMP N1A STATUS = ON RULE R3B IF NODE N1 DEPTH > 7 THEN PUMP N1B STATUS = ON RULE R3C IF NODE N1 DEPTH <= 3 THEN PUMP N1A STATUS = OFF AND PUMP N1B STATUS = OFF Important Notes It is best to only specify either a SWMM control set or on/off controls for a model. Using both types of controls can lead to conflicts. If you run into an error 217 about an invalid format when using an AND or an OR function, but moving the AND/OR portion to a new line. Not all modulated controls are currently available for use in SewerGEMS and CivilStorm. As of 10.00.00.45, SWMM Curves and Time Series cannot be referred to in controls. For example to have a pump follow a time series pattern where you want to control the speed of the pump over time, you would not be able to create a SWMM control with action like "THEN PUMP PMP-1 SETTING = TIMESERIES TS101". Reference # 772418. See Also Creating Controls - Conditions, Actions, and Control Sets Creating Controls - Conditions, Actions, and Control Sets for WaterGEMS and WaterCAD SELECTSeries 6
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Forum Post: Associating Hydrants to Pipes
The scenario is as follows: I have uploaded hydrants to Watergems via modelbuilder. This resulted in floating hydrants with no hydrant laterals. I am interested in finding the best way to establish a node in the pipe closest to the hydrant. The node would then represent the hydrant and have the same label as said hydrant. The goal of this is to eliminate the lateral length and hydrant altogether and have Fire Flow scenarios run and tested directly on the main pipe. I have tried making a tap in the pipe, but this results in associating the tap in the center of the pipe and does not establish a node near the hydrant. What would you say the easiest way to do this would be? I am very open to ideas and suggestions.
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Wiki Page: Wrong values exported to i-model with certain Windows Regional Settings
Product(s): SewerGEMS, SewerCAD, StormCAD, CivilStorm, WaterGEMS, WaterCAD, HAMMER Version(s): 10.00.00.45 & 10.01.00.70 (Storm/Sewer products) Area: Output and Reporting Problem When exporting to i-model, numbers such as elevations, flow, etc in the resulting i-model are not correct. For example a very large, unexpected value is seen for elevations as seen in Bentley Navigator or Bentley View. Solution This may be due to the Windows Regional and language options. Go to the Windows Control Panel > Region > Additional Settings. If they are not already set this way, change the Decimal Separator to a period '.' and the digit grouping symbol to a comma ','. Click Apply > OK. Next, restart the Haestad product and re-export to i-model. The particular problem has been reported as reference number 781126 and will be addressed in a future release of the i-model publishing engine. This has been known to occur in version 08.11.07.04 of the i-model publishing engine. You can check your i-model publishing engine version in the Windows "Add/Remove programs" or "Programs and Features". When available, please upgrade your i-model publishing engine version. The latest version can be found as a prerequisite to the Haestad product in question on the Fulfillment Center (download site). See Also What is an i-model and why does it show as a prerequisite? How do I publish an i-model?
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Wiki Page: The results of a transient run are not matching the steady state results of a valve set to a given setting
Product(s): HAMMER Version(s): CONNECT Edition, V8i Area: Modeling Problem The results of a transient run are not matching the steady state results of a valve set to a given setting. Background As a test to assure that the transient results are working as expected, you may run the initial conditions for a model not only on the starting position of the run (which is used at the beginning of the transient simulation), but also the end position. For instance, you may have a series of valves that are closing in a model and want to see how the model should look at the end of the simulation, so you may run a steady state with the valves in their final position. In some cases, you may see results from that final steady state differ from the end of the transient run. Solution This can occur because of assumptions related to how valves operate in HAMMER. Most valves will not modulate or see a significant change in the initial setting, even if there is some sort of pattern or rating curve associated with it. In some cases, like a PRV or FCV, the solution may be to model this as a TCV. The following link has more information on this: Modeling existing valves as Throttle Control Valves in HAMMER . If you are not able to find a suitable way to calculate the discharge coefficient for the valve, or if you want to try to simulate how valve follows a given pattern or rating curve, another option may be to use the Orifice between Pipes element. For example, suppose you have a GPV with a headloss curve. If you were to compute a model, you may see a given results for the headloss through the GPV. But since HAMMER will not following headloss curve, it will simply use the starting value from the initial conditions through the entire transient run. One way to workaround this would be to use the Orifice Between Pipes element. The Orifice Between Pipes element allows you to enter the "nominal" headloss characteristics and flow conditions. It then uses this to establish the headloss characteristics through the valve, and use those during the transient simulation to model how the headloss changes with flow. See Also Modeling Reference - Valves Modeling an Initially Partially Closed Valve Transient pressure wave not dampening or unexpected lack of headloss
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Wiki Page: LoadBuilder demand allocation for customer meters with taps and laterals
Product(s): WaterGEMS, WaterCAD Version(s): 08.11.XX.XX, 10.XX.XX.XX Area: Modeling Problem How can I use customer meter elements with taps and laterals, but distribute demands to them with LoadBuilder using polygon area loading information? Background The "Customer Meter Loading Data" section of LoadBuilder enables you to assign existing demands on customer meters to nearby pipes or nodes, or aggregate customers within a junction's service area to that junction. It can also automatically create the lateral link element and connect it to the nearest pipe. However, it asumes that you have already entered or imported the demands on your customer meter elements. In some cases, you may have each individual customer location included in your model, but may need to distribute demands to them based on a polygon shapefile. For example, using the Proportional Distribution by Area traditional LoadBuilder method, one can assign demands in this fashion to junction, based on the amount of area of the demand polygon that overlaps the junction's associated service area polygon. Solution Currently this cannot be done directly, but is being considered for a future release (Enhancement # 785028). In the meantime, there are a few options: 1) Import the customer points as junctions and distribute demands using existing LoadBuilder methods such as Proportional Distribution by Area. If the junctions are close to the pipes, you can use the Batch Pipe Split tool to connect the junctions to the pipes. 2) Distribute the demands to the points using an external application such as ArcGIS, then import them into the model as customer meters and assign to pipes (and connect via tap and lateral) using the Customer Meter LoadBuilder methods. 3) Import customer meters using ModelBuilder, automatically create the taps and laterals, then convert them to pipes and junctions and distribute demands using the desired LoadBuilder method: a. Use ModelBuilder to import the customer meter locations as customer meter elements, with no demands assigned. b. Use the Customer Meter LoadBuilder methods to assign the customer meters to pipes and automatically create the taps and laterals. c. Open the customer meter flextable and export to Shapefile using the export button in the top-left corner. d. Do the same for the taps and laterals e. Delete all the customers, laterals and taps. Use the Home tab > Select By Element. Once selected, right click > Delete. f. Create a ModelBuilder connection with the Taps Shapefile and map it to the junction table type. g. Once imported, run the Batch Pipe Split tool to connect the junctions that were formerly taps, to the overlaying pipe. h. Create another ModelBuilder connection with both the lateral and customer shapefile selected. Map the customers as junctions and the laterals as the pipe table type. Choose to create a selection set on import. Choose the option to specify connectivity based on spatial data, to ensure that the pipes are connected to the tap nodes (now junctions). i. Use the desired LoadBuilder method to allocate your actual demand information (which may be in the form of polygon areas) to the junctions that represent customer elements. Use the selection set from step h when choosing the node layer. With the above method, you will be able to re-distribute demands with the desired LoadBuilder method, as needed. If you ony need to allocate the demands once and would like to take advantage of the benefits of the customer meter elements, consider importing the customers as junctions, allocating the demands as needed, exporting those orphaned junctions to a point shapefile, copy/pasting the demands from the Demand Control Center to a spreadsheet, then import back as customer elements and their associated demands, then create the taps and laterals using the Customer Meter LoadBuilder methods. See Also
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