tag:blogger.com,1999:blog-1675184707067447729.post5386098778729722041..comments2023-07-12T07:12:04.697-07:00Comments on The RAS Solution: Using User-Defined Curves for GatesChris G.http://www.blogger.com/profile/00354834185663924786noreply@blogger.comBlogger17125tag:blogger.com,1999:blog-1675184707067447729.post-90398778237835253582018-05-06T09:07:22.130-07:002018-05-06T09:07:22.130-07:00Hi Bob. Did you ever figure this one out?Hi Bob. Did you ever figure this one out?Chris G.https://www.blogger.com/profile/03272464763887890080noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-49293604493553432312018-04-19T16:40:54.515-07:002018-04-19T16:40:54.515-07:00Chris, I just asked you this from another post as ...Chris, I just asked you this from another post as well, but it relates to this thread too. Does the user-defined rating curve assume water surface or energy? It's easier to develop your own rating curve based on WS than energy. I had assumed water surface, but I think it might be energy. We're doing some dam overtopping and breach runs where the EGL is really high, but the gate is submerged in deep water and I think HGL would be more appropriate. Thanks, BobBob Elliothttp://www.watershedse.comnoreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-56970705543226479152018-01-22T11:37:54.671-08:002018-01-22T11:37:54.671-08:00I'm wondering if there is a bug in hec-ras 5.0...I'm wondering if there is a bug in hec-ras 5.0.3 when you breach an inline structure (fair weather condition) that has a overflow (open-air) gate. The breach hydrograph is very pointy and small relative to what I'd guesstimate and the reservoir headwater is not dropping like I'd expect, it is just dropping a small amount. If I change it to the user defined gate option everything appears normal (breach outflow, drop in reservoir, etc.)Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-11723482804881737602017-09-26T12:58:20.946-07:002017-09-26T12:58:20.946-07:00Check to make sure that you have gate openings def...Check to make sure that you have gate openings defined in your user defined curves for all gate openings you may have. To be safe, over-extend your rating curve definition.Chris G.https://www.blogger.com/profile/03272464763887890080noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-2269539614648330122017-09-26T12:32:44.384-07:002017-09-26T12:32:44.384-07:00Hi Cris.
I'm having a problem that I cant und...Hi Cris.<br /><br />I'm having a problem that I cant understand what is happening in Hec Ras. I'm simulating a dam break scenario, in a way that my dam have a gate, with a user defined curves. When I run my project, I'm getting this message: "Gate Opening below Gate Curve at Hydraulic Structure" and "Gate Opening above Gate Curve at Hydraulic Structure" for the same hidraulic structure (Dam). My input data in the project are: defined curve for the gate starts in 529.6m and ends in 545m. The invert of the gate is 529.6, with 3.4m in heigth and 13.5m in width.My Boundary condition in this hydraulic structure is "Elev Controlled Gates", with maximum gate opening of 3.4m and a minimum gate opening of 0m.. The gate begins to open at 531.1 and begins to close at 530.9 in a rate of 0.03m/min.<br /><br />What could be the origin of this warning? What can I do?<br /><br />Thanks!Anonymoushttps://www.blogger.com/profile/09005020222726437403noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-28555846225396622272016-11-03T07:43:07.333-07:002016-11-03T07:43:07.333-07:00Hi everyone ,
I am trying to model a reservoir sed...Hi everyone ,<br />I am trying to model a reservoir sedimentation using the quasi unsteady hydrodynamic approach , I Have a problem in entering the T.S gate opening , should I calculate them? and how? I have upstream elevations of the reservoir for the Whole year and it is constant for every year , also I have rating curve for the upstream cross section and the downstream cross section located after the structureAnonymoushttps://www.blogger.com/profile/02631089987764648914noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-13560986270193366682016-07-26T08:23:04.544-07:002016-07-26T08:23:04.544-07:00Make sure you are entering in a family of curves-o...Make sure you are entering in a family of curves-one curve for each gate opening. At a minimum, you need a curve for whatever gate opening you define in your unsteady flow boundary conditions. Also, more definition in your curves is generally a good thing. If Q exceeds 50,000, you'll need more data points to keep RAS from extrapolating. Chris G.https://www.blogger.com/profile/03272464763887890080noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-16630454603507993272016-07-25T12:03:08.525-07:002016-07-25T12:03:08.525-07:00Hello,
I am trying to model gate operations at a ...Hello,<br /><br />I am trying to model gate operations at a dam with a user-defined rating curve. The dam operates such that between 0 and 50,000 cfs, gates are opened in order to maintain the elevation at 380 feet. The problem is I can't enter a rating curve as follows: <br /><br />WSEL ------- Q<br />380 ----------- 0<br />380 ----------- 50,000<br /><br />I've also tried shifting the elevations slightly (0 cfs at 379.9, 50000 cfs at 380.1), but the model begins generating errors, probably because the rating curve is too steep. <br /><br />Any ideas on how to model the dam? This is a low-budget project and modeling all the gates would devour the budget. Christinehttps://www.blogger.com/profile/04472371194878958072noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-63828201792726562852016-03-29T08:58:52.866-07:002016-03-29T08:58:52.866-07:00Yes, that is correct. Ht stands for "height&...Yes, that is correct. Ht stands for "height" and Hw stands for "headwater). It is not a ratio which is why I guess they used the back slash "\" instead of the slash "/", but I agree, it can be misleading. Thanks for pointing that out. Chris G.https://www.blogger.com/profile/03272464763887890080noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-6586147209058823762016-03-29T02:21:44.454-07:002016-03-29T02:21:44.454-07:00In the first column named "Gate open Ht\Hw&qu...In the first column named "Gate open Ht\Hw", I assume that the gate openings values are the heights of the gate opening. The header in HEC-RAS can be a bit misleading because Ht seems not to be defined anywhere and Ht\Hw can easily be misconstrued as some kind of ratio (though it would make no sense).Noteswithoutemotionhttps://www.blogger.com/profile/16037830668397974731noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-203167911715892632015-10-27T10:28:55.442-07:002015-10-27T10:28:55.442-07:00ThanksThanksAnonymoushttps://www.blogger.com/profile/03648310730259767698noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-19590249837426866752015-10-27T07:41:40.926-07:002015-10-27T07:41:40.926-07:00Yes, you can do it that way too. Yes, you can do it that way too. Chris G.https://www.blogger.com/profile/03272464763887890080noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-61941318084138147752015-09-23T09:47:38.852-07:002015-09-23T09:47:38.852-07:00Hi Chris,
In order to model a flow-regulating str...Hi Chris,<br /><br />In order to model a flow-regulating structure with a single rating curve, instead of going through the process you describe here can you just add a cross-section, then in the cross-section editor go to "Options" and "Add a rating curve"? They both seem to work, I am wondering if there is a difference in the way HEC-RAS computes the two. I am using 4.1 with unsteady flow. <br /><br />Thank youAnonymoushttps://www.blogger.com/profile/03648310730259767698noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-10252687736046739912015-08-30T18:21:42.768-07:002015-08-30T18:21:42.768-07:00Thanks for your responseThanks for your responseAnonymoushttps://www.blogger.com/profile/16415387017825602106noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-36921485396269073212015-08-27T10:16:08.746-07:002015-08-27T10:16:08.746-07:00With the caveat that hydraulilc model output is on...With the caveat that hydraulilc model output is only as good as the input and the skill of the modeler...YES! Certainly +-5 cm of accuracy is achievable. To add confidence to your model, you should run some calibration and verification tests first. Chris G.https://www.blogger.com/profile/03272464763887890080noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-59423507081602164332015-08-19T18:45:35.172-07:002015-08-19T18:45:35.172-07:00Thanks for this useful article. I have a question....Thanks for this useful article. I have a question. In irrigation canals, There is a a gate structure called check. The main objective of these gates (Checks) are to increase the water level in main canal to provide enough head for lateral off takes to get water. These lateral offtakes are quite sensitive to water level and any increase or decrease in water level could result in difference in water delivery to offtakes. I was wondering if Hecras or any other Hydraulic models are able to calculate water level with +- 5 cm accuracy in pools( By pool I mean the irrigation canal located between to checks), if I now the inflow and outflow time series for the pool(upstream and downstream gates flows).<br />CheersAnonymoushttps://www.blogger.com/profile/16415387017825602106noreply@blogger.comtag:blogger.com,1999:blog-1675184707067447729.post-45778631863688800452015-08-04T08:05:02.820-07:002015-08-04T08:05:02.820-07:00Very useful. Thanks Chris.Very useful. Thanks Chris.Pedrohttps://www.blogger.com/profile/13377232677191219766noreply@blogger.com