Episode 24: Ineffective Flow Tips and Recommendations for Internship Applications

foreign [Music] welcome to full momentum in HEC Raz podcast I am your host Ben Carey and here joining me as always Chris Goodell Chris welcome to episode number 24. that's a pretty cool number but even cooler than the episode number is the fact that uh we have crossed the 100 000 view threshold on our on our YouTube page that's a pretty remarkable uh accomplishment Chris that's pretty cool Ben yeah good to see you again and um that's really exciting it's it's it's it's cool that we're able to do this we're able to put some time into this and we've got 24 episodes while this will be number 24 right now uh we only started it a couple years ago roughly two and a half years ago and uh so I'm glad that we're able to keep this thing going I'm glad people are watching and uh we're getting a lot of good feedback too when we see people out at conferences or when I you know when I'm teaching classes or just bumping into people here and there so glad to see that people are finding use out of this and makes it um all the more encouraging for us to keep this thing going and yeah awesome well happy first of all happy holidays uh and then Happy New Year to everyone who's watching this this will probably be our last episode of 2022 and we do have some some exciting things coming in 2023 so first of all there's likely going to be some full momentum in HCC Raz podcast gear coming out next year so be on the lookout for that we're going to have some potentially a t-shirt or a hat and we might send those out to folks that are interacting with us on our YouTube channel the other announcement which is which is pretty cool is to celebrate our hundred thousand view threshold we are going to host a live vodcast on YouTube yeah uh the date for that is going to be TBD it's going to be sometime in in quarter one of 2023 so be on a lookout for that the idea is we're gonna Chris and I are gonna hop on it's going to be casual conversation just like this we'll have a few topics that we're going to cover um in the background and then if there's questions that come in from from folks on on the channel we'll answer those to our best of our ability but it'll be kind of a fun switch-up of what we've done so far yeah and uh show up for that too keep your eyes out so that you see when the date and time will be and then we're going to want to have as many people as possible to come in and it'll be a great time to uh hey you've got this lingering question you've always kind of wondered about this with Raz or maybe uh there's something weird going on with your model and you want to tell us about it we can talk about that or if you just want to chat about uh General topics whatever or if you want to ask Ben about Gonzaga and we will be taking Gonzaga questions how they're doing at the moment and his prognostication for uh March Madness coming up uh in a few months you can do that too yeah awesome and then uh last announcement for 2023 as we move into the new year is uh Kleinschmidt actually has an active listing out for a h h internship um and that internship is going to be in the Portland Oregon office so if you are selected for that you'd be working directly with Chris and I uh in the Portland Oregon office along with the rest of our awesome H H team out here in the Northwest uh and doing a bunch of different types of of both Water Resources engineering work it's definitely some HEC grass work uh as well as getting the potential to go out in the field do some things around different project sites that we have here in the Northwest and and also getting a chance to get exposed to non-water resources areas of clinch we pride ourselves as a company on being very multi-disciplinary and uh you know Chris and I even though we do a lot of H H work we interact with our scientists and our re-licensing folks as well as the other engineering disciplines that we have within the company so we hope that it's a very broad experience in terms of what people get but also I'm going to be able to to do some hardcore H H stuff which I think will be really really valuable for folks so anything else Chris you want to add about that that internship uh yeah so we're we're just looking for people who have a passion for Water Resources engineering uh we recognize when you're in college when you're studying you don't have experience necessarily um and so that's not as important to us it's great if you can show that you've done something that's applicable but we're looking for somebody more who has a passion and an excitement for the field who wants to learn who's eager to learn um because we can do that we can do that for you at Kleinschmidt and um give you an opportunity to work with us and learn some stuff before you go back to school in the fall yeah so um it's a great opportunity and it's a win-win for both of us so we're really excited to see who comes in what kind of applicants we get and uh hey Ben did you ever have an internship I did yeah I actually interned at a transportation engineering firm shout out to transpo group Up in Kirkland Washington uh it was a great experience but ultimately you know I ended up in h h and sure glad I did because now I'm here so did you intern ever anywhere Chris sort of sort of I I wanted to get something between my um uh Junior and senior years and there was nothing I could not get anything I I had a few interviews um I can remember one was at Happy Valley water district water Control District or something like that and um that's in East Portland area and um even went on site had an interview and thought it went well and didn't get it I was really bummed and I really wanted to get some experience because um I know yeah I knew coming out of college it's tough to get that first job and if you have some experience with an internship that's that gives you a huge uh Advantage yeah so what I ended up doing is I volunteered I volunteered yeah at the core of engineers and I said hey look I'll come in you don't have to pay me I'll do whatever you want just let me sit down and interact with you guys and you know take some load off and you know I had nothing else to do that summer I mean not nothing else but you know I had some time and um I thought well if I you know if I'm not if I don't have a paying job maybe maybe this will be the next best thing and it turned out that got my foot in the door the next summer I I had an um an actual real internship which led to a full-time job so I started it all off for me yeah that that's a great segue Chris because we're going to talk about things for uh in um people that are interested in getting internships things to consider things to do things not to do we do have also a really awesome technical topic today so Chris is going to dive into ineffective flow areas with NHC wraps I know that's a topic that we've had a bunch of people ask about so we're going to dive into that but before we go there let's transition back to interns because I know that this time of year in particular you know finals week I believe is this week people are going to be heading home for holiday break and a lot of folks are going to be probably submitting applications for internships for this upcoming summer so I know there's probably a lot of anxiety and uh people that are excited about this opportunity so we wanted to take a minute uh back at the beginning of this podcast series we did something similar in the spring for folks applying for jobs and new new College grads and things like that so I'm going to do something similar here talk a little bit about things to do things not to do when you're applying for and working as an intern so the first thing that came to my mind when we were thinking about this was you know particularly about resumes that get submitted for internships and I've you know given that we just posted this position I've actually already seen a number of resumes and there are things that stand out right away about uh things like oh I'm glad that person added that to their resume and not sure that that presents much value so the first thing I'll start off Chris and I'll throw to you is items on your resume when you're a sophomore or a junior in college that are tied to what you did in high school not super relevant probably not going to move the needle and separate you from other applicants and that's really what the whole point of a resume is is to separate you or add topics that people are interested in discussing further with you and you know whether you played Sports in high school what your GPA was it's probably not going to move the needle a whole lot when somebody's looking at your resume and potentially thinking about bringing you on in terms that's the first thing that popped into my head what popped into your head Chris and we're talking about well to do and not to do well would there would there be a benefit to somebody telling you that they played pickleball now would that get them some points see it would only because that would mean that that's and that leads into another item to do which is do a little bit of background research on the company and the people that you're potentially going to be working with because I think because what you're stating that is true if you you know play Pickleball now that's that's a sport I obviously it's not going to impact your ability to do water resources engineering but it shows that you took some time probably and researched Klein Schmidt research myself maybe you followed the vodcast and so that shows some initiative and that's my second item which is you know do a little bit of research on the company that you're applying for or the people that you're going to be working with and cater your resume to that and that's going to show that initiative because one of the more important things that an intern can have is initiative if you have initiative and if you have enthusiasm you're probably going to have a pretty good experience as an intern so that's another one Chris what else stands out to you well I can yeah and I can I can't tell you how many resumes I've gotten over my career where um there'll be a cover letter and the person will say hey I you know I think I'm a great fit for your company um blah blah blah they talk about how great of a fit they'll be and then it turns out that they have no water resources background at all they're a structural engineer or something like that and it's it then it becomes obvious that they were just throwing out resumes you know just a big wide net which you know it's fun fine The Gunshot method but you know it's not gonna like you say move the needle for us so what we're looking for is Passion you know and excitement for the field and if you do have some Hobbies or activities that are related to Water Resources maybe you're a kayaker and you want to put that on and then in your cover letter talk about how you let you love Rivers you love getting out there and understanding the flow of water through natural system you know that stuff I like to see um I like to see stuff about the classes that you've taken and that have really interested you um that are relevant to this to this work that we're we're going to do so um tell us about that because again you're not necessarily going to have work experience and that's fine that's not a requirement for an internship but what is a requirement in my mind is having an excitement and interest for this field and so that's you know however you can show that and demonstrate that in a resume and a cover letter that's what we're looking for yeah another one that pops into my head right away is is experience using computer software and it can be really any software right it's kind of unfair to expect that our interns are going to have user as quite a bit but if you have experience working with software troubleshooting that software working around different bugs and issues if you have any coding experience from school that's obviously going to be something that you're going to want to put on so any relevant experience to working with computer software is going to be a huge plus make sure that you highlight that even if it's small even maybe it's maybe it's just a lot of experiences in Excel Excel is something you're going to use a lot of as an intern so that's not something to shy away from and be embarrassed that that maybe is one of your more refined technological skills so that's something that stands out to me to me Chris what's another one that you know when you when you see folks put something on their resume that you're like I just don't see the value in doing that that doesn't that's not a separator for me so something that's not a separator um yeah you know you kind of mentioned like high school jobs and stuff um I would say you know even even jobs in college that are not relevant um you know everybody's gotta make some money um to pay the bills and pay tuition and whatnot and so maybe you were uh um I don't know um a dog walker or something and that's great but it's not you know it's not something that we're going to care too much about and so focus on the stuff that has to do with this internship or whatever internship you're going for make sure you highlight that that kind of stuff that's what we're just looking for well and here's the other thing too I get this question from people a lot and not necessarily for internships Ben but for even for your their first job and they want to get into water resources engineering and they say what do I need to show on my resume what's the best thing and I always say show that you have experience with hecraz and HMS and show that you can do some coding whether it's python or VBA and if you don't have those skills guess what you can get those on your own you don't have to take a training course you don't have to take a class you can literally go to the HCC website and you can you can self-teach yourself tech grads or HMS you can go online and there's coding academies that you can do there's coding boot camps things like that just do that get some familiarity you don't have to be an expert but that demonstrates that you've got interest enough that you're going to take your own time to teach yourself this stuff up front and that's the kind of thing we're looking for yeah and even if even if that doesn't happen you know even if you're behind the eight ball maybe you haven't had time to do that in the internship you know deadline is due Express in your in your resume or in a cover letter that you're really excited about learning those things right yeah hey I haven't I don't have Rad's experience but I've listened to some videos from Chris and Ben and I've taken some classes that have discussed her as and I'm really excited about learning this important software because again that goes back to that enthusiasm orgasm even if you don't have the skill you'll get the skill we just want somebody that's interested the last thing that comes to mind for me is about the regionality of where your company is that you're applying to we get a lot of applications from folks that don't live in our area which is fine there's nothing wrong with that but it's really important to note whether you're willing to both move to the area and if you expect or need some sort of housing compensation because a lot of times we'll get applications from folks that they appear to have a really good resume but they're you know maybe in Florida for instance and if if we're choosing between different people if you haven't expressively told us that you're willing to move to Oregon and you don't necessarily need a housing stipend that might be a tiebreaker situation where we go with somebody else for an interview over yourself so if you're if you're available and able to do those things make sure that you list them in in the resume because again that's a high that's a separator when we're choosing between this Ben would you be willing to house an intern if they agreed to do your yard work for you I like doing yard work so I'd be less likely to have somebody live with me if they wanted to do so but anyway so just a couple of things to consider there uh as as we move into internship application season I'm sure I get this biggest thing I would say enthusiasm initiative do some research show what you know uh even if you haven't learned in school you can self-teach it I think all these points that we've covered are all really really good takeaways yeah and hey here's a very easy easy thing to do takes may take a half hour hour of your time is get your LinkedIn page up and running and demonstrate on that how excited you are about Water Resources engineering and computer modeling and rivers and streams and things like that you know linked to articles about it um just even have your own personal commentary we just want to see that you know you've got that excitement and that's one way to do it too yep good good all right well so if you haven't applied already and you're a sophomore or Junior uh in college studying engineering for hopefully Water Resource and Engineering uh go ahead and go to kleinschmidt's website website that's clinchmentgroup.com and there's the internship posting under careers there send us your application we've already got a number of applications a number of interviews lined up so if you're thinking about it do it soon because you never know how quickly that window is going to close and uh Chris and I are excited to work with whoever whoever comes through yeah and if you're not if you're not looking for an internship maybe you've already got a job maybe you're uh 20 years in um to your career but you know somebody please send this to them yeah share the link with them absolutely they can get some of this info yeah great well good conversation there Chris let's turn it to a more Razz focused discussion so today's technical topic is going to be about ineffective flows and ineffective Flows at least when you approached the subject with me was one of those topics that I was like man we could do a three-part series on ineffective flows there's a lot of ground to cover when it comes to this so this first discussion might be a little bit higher level and depending on how it goes and the type of feedback we get maybe we'll do a follow-up and get a little bit more in depth but I'll turn it over to you Chris to leave the topic and uh yeah okay so first of all I want to start off with just an explanation of what ineffective flow is not everybody knows what it is or maybe they're not totally sure about it but the definition of ineffective flow as far as how it's used in hecraz is flow o that is not actively moving in the downstream Direction now this only applies to 1D modeling because in 2D modeling you are Computing flow in all directions so we don't even need ineffective flow for a 2d model but if you are building a 1D model you need to identify areas where water is not moving in the downstream Direction the software won't figure this out for you this is up to you to determine because 1D models only look at water moving actively in the downstream Direction so let me share my screen give you some examples of ineffective flow and you know I'll tell you Ben I uh first thing I did was I Googled ineffective flow um and just to see what would pop up and not a whole lot of examples visually or or you know imagery wise of ineffective flow but when I typed in Eddie patterns in River Rivers I got all sorts of websites with pictures and and uh descriptions of ineffective flow even though they don't call it ineffective flow so this is one website that popped up this Cali paddler so this is all about paddling in rivers and this first article here is understanding Eddie currents in rivers and so you can immediately see in this figure I'll actually get to a better one right here that same figure and you can see where water is separating to go around the substruction in the river and then what happens just below that you get this yeah a shadow effect or Eddie's and actually where the water the the boundary between water moving in the downstream Direction and water circulating or not moving the downstream direction is called the Eddy line and um those of you who who like to canoe or kayaken rivers are very familiar with the Eddy line because the Eddy line especially in a strong River can flip you over in a second like if you're not ready for it and if you attack it at the wrong angle because you've got high velocity here and essentially no velocity here so if you were to come out of this Eddy and nose into the river it's going to spin you around and if you know you got a wobbly kayak it'll flip you over so you got to be ready for that but as far as hecaraz goes what if we had a cross section right here Ben right across the river just Downstream of the rock you're gonna have to tell Raz that this is water not actively moving in the downstream direction right yeah so it takes some experience to know where that is and how far that Eddy line projects away from the obstruction so you know technically where you're going to put your ineffective flows from Eddie line to Eddie line yeah you have a cross section here yeah it's funny looking at this too because the first thing this obviously isn't going to be a topic today but another thing that comes to mind is just how this particular situation that this figure is showing um you're only going to be able to get that if if you're doing 2D modeling using the full momentum set of equations right because if you try to model that using the diffusion wave set of equations you're going to not be able to represent those patterns so there's applications here when we talk about ineffective flow areas in the hydraulic phenomena that are associated with that there are applications both to 1D and ineffective flow areas which we're talking about today but also for 2D so just something no it's a really good distinction um one one thing I wanted to ask you Ben is what if okay so we talked about a cross section right here just below the wrong what if I put one out here about where these green arrows are so that it looks like the way at the downs you said Downstream yeah Downstream about if my cross section was out here what would I do with ineffective flows yeah so at that point it looks like the flow has reestablished into normal flood pattern so I don't believe that you would have any more ineffective Flows at that point exactly so you know according to these green arrows it's now moving Downstream so now we have effective flow we have flow actively moving in the downstream Direction here so cross section here would have no ineffective Flow Design defined on it but a cross section right through here would and same thing on the Upstream end if I had a cross section out here before the flow has started to bend to go around the rock no ineffective flow but if what if I had one right here and you got this flow that's going sideways sideways flow is ineffective flow that's not moving Downstream right yeah and so yeah so you would make a little bit of ineffective flow on that cross section just Upstream of the rock now here you can see that Eddy line right and this is the Swift moving effective flow here but over here you've got the circulation pattern defined by these red arrows and um this is going to be ineffective flow over here yeah this is yeah yeah so I think one of the first things that comes to my mind when I'm thinking about this is you know some folks struggle with withdrawing the ineffective flow lines and where those are and there's obviously some some guidance out there that can be a default in terms of the the angle of that ineffective line coming into the expansion or contraction but uh the best way to really draw those lines is if you have some photos of the area or if you have some aerial imagery of the area you can utilize that to pull out these Eddy lines and and you can it almost shows you exactly where the ineffective boundaries are so when we get into some of the recommendations and whatnot those are great if you don't have aerial imagery or photos or videos of the site but it's always going to be better to to have some site-specific information to draw those in yeah and this I mean this really highlights the importance of getting out to the rivers to The Rivers often you know whenever you can um you know if you're a water nerd like Ben and I are um you do this all the time even to the you know displeasure of our families as we're on vacations or whatnot you know hey let's go look at this River and they're like why Another River why do we have to go look at that well you're studying things like that you're getting a feel for how water separates off of obstructions and that's exactly where an effective flow sets up when you have these separations off of obstructions you can even see it here with this rock there's a little ineffective flow zone right here you know this is a little Eddy pattern um you can sort of see it here you can see it on the other side too where it's separating off of this um point right so here we've got ineffective flow here uh you can see it again in in this this view here he's crossing the Eddy line so you can see how he's got a wide stance so he doesn't tip over and I've done that before by the way been in a kayak not not on a paddle board but I think the first one of the first times I went kayaking I just zipped across the Eddy line it flipped me right over so fast so anyway so this gives you some visual examples but hey get out to the river and this gets back to the passion thing if you you know if you're interested in having an internship with a firm like ours and you want to do a lot of resources you should be getting out to the river whenever you can uh even if it's just to hike alongside it you don't have to be in it but being in it gives you a whole nother perspective on things that's right I agree so let me pull up a I built for a demonstration here I built a what I call Flume model but this is just a trapezoidal flume uh it's it's one kilometer long but the the length is really irrelevant it's just a trapezoidal channel right and so with nothing in here it just flows straight through pretty boring stuff but what if we wanted to simulate uh bridge embankments and so um you've got this embankment on the left side and on the right side and you've got water that's going to be coming Downstream and it's going to contract to go through that opening and then expand out again and we would expect to see flow in these Corners that is not actively moving in the downstream Direction so let's take a look at that so here we've got flow that's squeezing through here and if I turn on my particle tracing you'll be able to see that a lot better so there you can see how it's Contracting to go through that opening and expanding at the downstream side you can even see some Eddy patterns right here okay so here's the Eddy line right and so here's the contraction you don't really see a distinctive Eddy sometimes you'll see a small one in this corner here but it's able to contract more efficiently because it's a little bit slower on the Upstream side and so usually your contraction zone is a much shorter distance than your expansion Zone on the downstream A good rule of thumb that Ben and I use is one-to-one contraction rate and a two to one expansion rate that's a pretty common rule of thumb that people use but really all bridges are unique all flow obstructions all contractions expansions are unique in rivers so you need to really decide for each case but a good knowing nothing else a good approximation would be a one to one and a two to one and you can kind of see that right um you can kind of see that one to one two to one thing going on this is a more kind of academic visual of that right so Chris's is much more practical with that 2D model but this is I think maybe directly from the the HCC hydraulic manual but this is the appendix B yeah the one-to-one slope on the Upstream side of this uh bridge opening here and then two to one on the downstream side and again this is approximate so this is a good starting point but it's also uh it highlights how every single project every single location that you're putting in ineffective is going to be slightly different you might have some skew to the bridge there might be some blocked areas in in the middle of the river channel here that that change what those slopes are but this is a good starting point um if you if you have nothing else and if you don't have uh you know the 2D model that Chris is that Chris is showing here so um yeah I think so I wanted to show too is is uh you know Chris had that visual example of the Rock in the middle of this tournament how that's a blocked obstruction that creates its own ineffectives here's another example where we have a culvert right so flow is moving from Upstream to Downstream here and this isn't a blocked obstruction right this is actually the the conveyance primary conveyance area here but this is the downstream side of that and so in this case you're their expansion contraction lines and your unaffected flow lines would be somewhere out here and you can see how much calmer the water is here it's not really actively conveying Downstream compared to the middle here so this is just another kind of visual example of what we're talking about you can almost see the ineffective flow in this image right yeah if you were to go draw in a line here to represent that you know it'd probably be change the color here so it's a little bit easier to see something like like that on the downstream side it's a little bit skewed just simply because of the fact that we're at a kind of an angle of the image here but it almost looks something something along those lines there yeah something like that so even I might even swing it out more because you can kind of almost see what it's like current down there yeah yeah like standing out yeah it kind of gets into this kind of gets into the mess of trying to represent this linearly with a single line and Chris I'm gonna have you go back to your image and show this because it isn't a straight line expansion right there's almost some curvature to it like if we just draw the line to here you can see that's pretty representative but then as we get further out you actually want to bring this line out maybe closer to to something like that and so Chris if you want to pre-share your screen and show that that image that you had I think that does a good job of illustrating that that's not a straight line it's the approximation that we have is is good but it is is more complicated than that and this 2D model shows that yep yeah it bends like this on both sides there's curvature to it but you know we usually will I mean if you have multiple cross sections through here then you can try and simulate that curvature but most of the time we just approximate straight line through here two to one expansion one-to-one contraction up here so this would be an issue if we were to make a 1D model out of this and or maybe we we didn't even have a 2d model we were just starting with a 1D model and we had cross sections upstream and downstream to this bridge and you know going both directions you would want to Define this Eddy line or the ineffective flow Zone with your ineffective flow triggers at any time um now in the four cross-section setup that's commonly used for Bridges you would have one cross section on either side of the bridge really close to it and then you'd have a cross-section Upstream where flow first begins to contract so probably about right here and that's what that one to one will Define and then you want a cross section Downstream that is where flow has finally expanded out to the full width which is about like right to here and so that's where you get the two to one that's at a minimum the number of cross sections you need around a bridge that's the four cross section model but you can have intermediate ones in there you would just Define that expansion or in this yeah the expansion flow here or contraction on the Upstream side so what about a case been where if the water gets high enough it starts over topping the bridge yeah so in that case it well first of all I will drastically change your ineffective lines um and yeah in some ways it'll completely get rid of them and that's when we talk about the nuances of applying ineffectives one of the more important things is to decide or to know what the flow level is that you're modeling because these ineffective lines change and they can change pretty drastically depending on what the flow level is um it's it's really one of the when we talk about advantages of 1D and 2D and how those those two different types of modeling software are kind of beginning to separate themselves one of the real advantages of 2D is the fact that as the flow level change changes within your within your model boundary your geometry your underlying terrain data and the way you have your mesh set up is going to automatically take into account how those ineffective areas change and don't change 1D model is going to be a lot more limited you're going to have to be a lot more uh interactive with it to really represent that appropriately yeah exactly so that's a huge benefit for 2D modeling but if you are doing a 1D model you want to make sure that you know the elevation at which the ineffective flows will turn off so if we go back to the low flow example here we've got it going squeezing through the opening but as water increases in both flow and Stage eventually it's going to get high enough to go over this embankment and that's what we're showing right here on this example and so you would want to know okay what elevation does it start to over top and a good first estimate is let's turn on this profile line here so you can see what we got once water gets to the deck level then you would want your ineffective flows to turn off so you would put an ineffective flow trigger here and here just outside of this opening and you would call all of this over here ineffective flow both on the upstream and downstream side but once the water goes over the top then those ineffectives will turn off because we have the trigger elevation set at the same level as the um the crest of the embankment which is 20 meters in this case and so that's how you have you set your elevations for your ineffective flow so when do you think that flow is going to become effectively moving Downstream that's when you want that elevation or that trigger to turn off so that's how you set the elevation for it so we've talked we've talked about how those lines converge towards your contraction or towards your blocked obstruction we've talked about the elevation of the ineffective flow area and when that you know more or less turns off and and flow starts to convey one one other thing I want to touch on really quick Chris if you go back to that visual you were just looking at is the idea of permanency with an ineffective flow area so if you open up that that line you just had you're talking about this one the profile line that shows the Water Service elevation compared to the terrain so if you look at this like Chris noted at a certain elevation in this case right around 20 meters you're in the Upstream area is all of a sudden going to be starting to convey flow towards towards this this bridge opening and so you're an effective area is kind of is going to be eliminated at that point unless you assign that ineffective flow area to be what's called permanent within the HCC res software and I know there's a lot of questions that's one of the biggest the the most frequent question that I get is do you use permanent or non-permanent ineffective flow areas for an example just like this and it depends on a lot of things that's what I always tell folks the most important thing is what's the distance between your last cross section where you have an effective flow areas and that structure that that is causing the ineffective flow area because if that if that cross-section is right up against you know maybe just a few feet or a few meters from the bridge deck or from these abutments it it's reasonable to assume in that case that the ineffective flow area that you have there is permanent which means if you have a permanent ineffective flow area all of the area in this case that's being blocked by those abutments remains ineffective but any area that's above that any water that's above this abutment deck in this case would be effective so it's kind of combining the two and that's a realistic picture because if you were for instance to to swim underwater up against a bridge deck that's being over topped that water below the top of the bridge deck really isn't effective it's not moving through that bridge deck it's only the water moving over the top that's actually effective however the opposite case where that cross-section is actually further away from the bridge deck you might have that entire water column that is suddenly becoming effective uh if you if you're over topping that bridge so any other thing you want to add there Chris or thoughts about permanency let me uh I always like to explain this with a sketch I've got a sketch going here and so here are the two cases that Ben was just talking about so this is profile view water's moving this direction on both of these examples this is the the bridge embankment where we've got vertical walls and walls and here's one where we've got sloped embankments now where you're going to want to put your cross section let's make our cross sections green is for this case I mean for both cases you want to get them as close to the dam or damn the bridge or whatever the start of the structure yeah as possible and in this case we've got all this embankment here so we would want to put it near the toe of the embankment on both sides right all right so oh that's a bad Crossing but you get the picture so again this is this is um profile view so we're looking sideways at it now if I were to draw the flow lines okay in this first example you got flow lines that are going to kind of do this right yep it's going to be something like that right so all of this over here is an effective flow but just kind of in a sideways perspective versus plan view perspective so in these cross sections that I have here these two green ones that's even though it's over topping the embankment this is ineffective still so we would call that permanently ineffective now in the case down here if we go back and draw our flow lines again they're going to look pretty similar right but because of the position of the cross section we won't have permanent ineffectives on there they'll actually as soon as it starts to over top you would want to make these non-permanent so they would turn off because all of this the entire water column would be activated yeah so it kind of capture what you were talking about Ben exactly Chris this is beautiful I have a couple things to add here so on that upper figure go ahead and draw another cross-section Upstream that we would have the ineffectives as non-permanent so just a far enough upstream and just far enough Downstream so exactly there and if you draw another one Downstream so in this case both the crop both the cross sections that are right up against the structure and the cross sections that are a little bit further out those both might have an effective uh boundaries or ineffective areas drawn on them before that structure begins to over top but yeah once that structure begins to over top now all of a sudden those outside cross sections are going to be non-permanent so those are going to see um active flow when that's over topped and then the interior cross sections because of the shape of the structure they're representing are going to remain permanent and effectives and so this does a good job of highlighting how that changes versus again if you look at the lower figure all your cross sections both right to toe of the structure as well as ones upstream and downstream those would all be non-permanent and effective flow areas so this is a great visualization the other thing I want to point out which is fascinating Chris I didn't think about this until you literally drew it right here you said that this was looking in the side view and it is non-plan view in terms of the ineffectives and how that the red kind of circle that area that you drew in represents the areas that are non non-non conveyance um but if you actually flip this and you pretended that that was the abutment and we're looking at it from vertically it's the exact same and so that contraction of flow moving over the top of this Weir in this case is almost the exact pattern that you would see of flow Contracting through a bridge opening from above so really no matter the perspective that you look at it you still kind of get that similar ineffective area either right up against the structure if we're looking at it into the page or on the Upstream side as as water conveys through that that contraction so that's that's pretty interesting yeah yeah that is um yeah so yep you get both vertical and horizontal contraction expansion of flow and we need to account for that in rats because we have a 1D model we don't have a 2d or 3D model when you're doing 1D whereas with cross sections yeah so let me show you another example this is the case of an obstruction in the middle of the river kind of the same type of thing only here now you've got water instead of squeezing through the middle you have it squeezing through the outsides of the channel and this looks very similar to that image that I showed almost exactly the same discussion right yes um let me pull this up here right looks exactly the same doesn't it and so here again if we were to put a cross section right Upstream of this obstruction which is what we would want to do then we've got some ineffective flow right about in here same thing just Downstream of that we've got ineffective flow here and you can see this is a maybe a little more than a two to one expansion um and this this is probably a one-to-one contraction roughly um so you could set that up too on those cross sections just like you did with a bridge yep now last thing I want to get into is a little bit more advanced discussion on ineffective flows and certain applications so with that I'm going to get back into my my canvas here do some painting so let's get rid of all this stuff and I'm going to draw a plan view of a river so we'll make this brown because that represents the banks and so here we go plan view of the river and um let's say we got some kind of feature that sticks out here like this and it comes back around and goes Downstream this is what you might call a Backwater Slough right and we're gonna have some cross sections all throughout the water is going this direction okay so let's put some cross sections I'll put one here oops I just drew it the wrong direction I'm sorry first let's do it the right direction you'll get it you'll get a negative flow on that one there we go yeah left to right is if you're looking down the string okay so this is how I would draw these make sure you want to capture that point with that feature maybe you got another one here and then another one right before it ends then another one right after and then you know keep going Downstream right and so this inside of these Brown lines is all water and you've got water actively moving Downstream but if the water is low enough that there is a barrier to flow right here then you'll get water up here but it's just going to be stagnant water it's called Backwater right that's why it's called a Backwater Slough and so on these cross sections I would want to Define this as ineffective flow right here and here and here yeah so do you want to draw those locations where you put those ineffective points on these cross sections so we'll make our ineffectives in this case orange and I would put and in fact a right there oh let me do let me do something different here I'm going to make them nice and thick so you can see it okay put some ineffective oh my gosh I messed that up there in there yeah I think you get the picture yep right so those are my ineffective zones and I would do these with probably blocked ineffectives or I don't know you could probably have it go all the way across um if this ground is high enough so those are my effectives but what about the case where water starts to get a little bit higher then and now it's doing this it's not only going Downstream but it's also coming in like this yeah so that would be that would be again a case when we talk about setting those ineffective areas it's going to be based on identifying that that's a Backwater slew so the location that you have is perfect Chris the only other thing to consider is the elevation that you have those at right so we're going to want to tie those elevations in with the elevation of the ground just Upstream of that of that cross section so I don't know if you want to draw kind of maybe a red line along that ground feature where you'd want to pull that elevation from to establish the elevation of those ineffective flow areas so it'd be right along here exactly something there you know take your best guess but in the reality is you're going to run the model and then you're going to come back and check because what you're going to want to do is you're going to want to see when does water first start going over this High Ground feature and whatever the water level is at these cross sections when it first starts doing it that's how you would set the elevation of these non-permanent ineffective flows yep and the only other thing I want to add to this particular image is one of the things that I see when I review models from people which is oftentimes people will just go ahead and add that high ground Peninsula that you have there they'll just add that in as as a levy with the assumption that hey water's not getting over there particularly if that's not a Backwater slew maybe it's just a low valley or whatnot behind there and they add levees there to restrict water from getting over there but that is a pro it's problematic because if water gets high enough to over top that High Ground feature there uh you're not going to be accounting for the fact that now all of a sudden that area is effective in terms of what the flow is so um yeah so my straw your example right okay yeah so here we have this low area over here right yeah um and this High ground and this could be a levee it could just be natural high ground here and we've got our cross sections right here oh I drew it backwards again oops oh well so embarrassing um you know here's our cross sections right and then we got more upstream and downstream and sometimes this is even lower than the invert of the main Channel I've seen that happen before yeah it's a little bit weird but before water goes over the top of this we would not expect to see water in here unless there was like ground water seeping at night um but you would not expect water to be able to flow in here from the river until it over tops that and so Ben what you were saying is in that case we should put um yeah we'll just call this my symbol for Levy markers although in Raz it's a pink triangle but yeah um anyway so we would want to put Levee markers here and what that would do is that would prevent water from going over into this area until the water in this on this side gets higher than these Levy markers then it's able to spill over there that's one that's one way to do it but the my caution with that is oftentimes people will put levees there thinking that water is not going to get over into that low area until uh the water over tops that that Levy or that bank but they don't look Upstream they don't look upstream and see if there's a a lower elevation that would actually activate that that low ground feature on the right bank and so that's why yeah exactly I really caution folks um if you're if you're finding yourself using levies uh really I I taught caution against it unless it's a clearly defined a certified Levy structure because there's a lot of different ways that water can get in there upstream and all of a sudden that area should be conveying water and you don't have it being represented as so because computationally Chris correct me if I'm wrong you're not going to get different water surface elevations different depths different velocities in the channel if you use an ineffective boundary or a levy it's going to have the same results in the channel the only one that you yeah for a 1D result yeah the only difference is is you're preventing water from getting over there and unless you're sure that can't happen based on your Upstream geometry you really shouldn't be using levies so yeah it takes some three-dimensional thinking yeah here for sure and um a lot of trial and error common commonly when you're building these models you don't just build it and set your ineffectives and off you go you have to look at the results and make sure that you've got them set properly not only their locations but their elevations as well yeah and then the last I guess last Board of advice for folks on ineffectives from me would be it kind of goes back to one of our mottos from our our 1D 2D class that we teach online which is start simple and add detail where needed so many times we'll get 1D models from folks that just have ineffectives everywhere and it's it's just a mess it's a massable to review and it's a mess computationally and so I would highly recommend when you're adding effectives and start with no ineffectives in your model at all run the model make sure it's working and then go through and add these in effect is where you really know they should be because oftentimes we'll have people drawn in tons of ineffective areas before they even run the simulation once and then they get some errors and instability and their models crashing and it's hard to know if it's related to all the air ineffective areas or something else so uh just a word of advice there make sure you're running your model and slowly adding these ineffectives in where you need them agreed yeah nothing is more of a nuisance than an over complicated model especially if you're reviewing it and trying to understand what the heck is going on um here's a to just to wrap up this is an example of uh or this is the Bald Eagle Creek example everybody gets this with the software it's one of the example data sets if I zoom in over here you can see these pink squares I call them triangles but they're actually squares those represent Levee markers that we were just talking about and if you look closely you can see some green Triangles around a lot of them are on either side of these bridges that you see here those are ineffective flows so um how do you set your ineffective flow so well there's a few ways to do that if you go right into the cross section editor you can see under options there is uh ineffective flow areas and this pulls up what I would call is kind of the old school way of doing it where you put in your you type in your left and right stationing for your ineffective flows and the elevation that goes with it so if I wanted to put something around say 180 and another one around 320. and then maybe I set them both at 670 for my elevation click ok and they're my ineffective flows okay that's saying everything to the left of this one and everything to the right of this one is going to be ineffective until the water gets above that level unless you go in let's double click on this this will take us back to the ineffective editor if I turn these to permanent now they will remain ineffective even when the water is above it yeah so if you click and if you click OK Chris you can see the visual difference too because I believe they that Bay Area becomes hatched it does once you have output okay here okay yeah so because I haven't run this yet it's not going to show it as hatched yet but yeah you're right you're right it will it will show if the water's up above it it will show this as a green hatched out area if it's permanent if it's non-permanent and the water is above it then that hatched area will go away as soon as the water gets above these elevations so that's kind of the old school way of adding them in and you do them one cross section at a time there's also multiple block option here which is a little it gives you a little more flexibility it also is a little bit more cumbersome to add these in so let's clear those old ones oops that's clear oh it's already cleared okay and then I'll show you how you do a multiple block you put the starting and ending station so let's say we'll go 50 to 100 on here we'll use the same elevation 670 and we'll say n or not permanent and then maybe I want another one at uh 150 to 200 and we'll make this one a little bit higher and then I'll maybe on the other side I've got like 350 to 420 and we'll make this even higher you can put ends on all of these and usually you're going to do multiple blocks if you have some sort of slope structure that you're trying to capture the slope ineffective area that you'd have you probably wouldn't have a gap in between those two on the left well in your structure or something yeah that's if you're doing a structure but this these could represent other obstructions like a building yeah this this Shadow like you know the um the example I was just showing you uh where did it go yeah yeah so this is like yeah that's a floodplain model and you have buildings or something yeah so here here's where you would use a blocked obstruction because you wouldn't want this to be ineffective or this to be ineffective you just want it in this one single block yeah and so that's kind of what we're seeing right here imagine this is a big boulder in the river or this is a house or you know whatever um something that's blocking flow so that's how you do it in the editor cross-section editor but if you look at this button up here this takes you right to the graphical cross section editor this is so much easier now you don't have the same level of precision but I can put in and adjust my ineffective flows I'm already in move mode but if I right click on here I can add more blocks maybe I want to put a block here there maybe I want one here okay I would never propose doing this this is crazy but um so I'm going to delete all these I think I have to click on them so you can do all this stuff just by clicking now if I get this back to what what it was I can right click and I can go add a normal ineffective and I just have to go boom boom oops I thought that was the left one got to get outside of the main stations yeah yeah so those are mine and then I can go to the next one and I can go boom boom like that now again you're not gonna have the same level of precision but it's a really quick way of setting your ineffective and the reason I like this Chris is if you do a side by side of the geometry data editor and this graphical cross-section editor so you have both you can quickly add them and then look at what the lines look like in the geometry data editor so you can kind of see hey do I have one-to-one slopes on the Upstream side of this contraction do I have roughly two to one slopes on the downstream side and kind of adding those in quickly is a great way to get those lines in place I don't know if you have the ability to kind of show what I'm talking about there but if you do that and you kind of get your lines drawn in where you want them then you can go back into the detail cross section and actually adjust the elevations to what they should be after you've drawn in the lines themselves yeah so you're talking about using this plan view here to see the contraction expansion right exactly as you draw those in the cross-section so yeah you could zoom in here and let's say that we wanted to show this one-to-one contraction here two to one expansion let's do the expansion so I can come over here and go to graphical cross-section editor here's my main Channel get into normal ineffective mode okay I know it's going to be a little bit wider than the bank station so maybe I put one here and one here then arrow down and back up and let's see where it shows up there you go so that actually turned out pretty good what I like to do too is I like to change the color though so they're easier to see yeah edit lines and symbols go down to my um ineffective where is it all right you see it's right there it's right about oh yeah schematic ineffective yeah and I changed the symbol color from this color to uh something like red red well that would look like a bank station so yeah pink will be good uh anything that's contrasting and then I'll a lot of times make them bigger too so let's do that lines and symbols schematic in effect it's definitely one of the biggest mysteries uh for HCC Ras if we should do an episode sometime on the mysteries of Razz decisions because making the green the triangles for an effective green has to be one of the most perplexing things I have no idea why they did that it's like yeah that's kind of weird it could have picked any color uh so but yeah I think changing the color and getting those bigger is is an awesome way to to be able to see them more clearly and then like Chris is doing right here so you draw those in see that you're expansion contraction that looks great and now you would go back into the detailed cross-section editor Chris so if you go back okay you got my uh you got my OCD triggered here okay so now if you go back to the detailed cross-section editor of those cross sections and now you would want to adjust the elevations of your ineffective so if you go to options in effective flow areas so now you'd want to adjust those elevations based on the elevation of your Bridge Upstream which is causing that contraction elevation so it's kind of a two-step process to get get the lines the contraction expansion expansion lines drawn incorrectly and then get the elevations correctly based off the the structure information you have so yeah and this one's already set at 566 564. so a good first cut would be nice to adopt those and we'll go yeah yeah so you would change that to 566. 564. now you would definitely want to run this and double check that that that's making sense but yeah it's a lot easier to draw those in in the graphical cross section editor as opposed to trying to type in what the numbers are and guess it's just it's too cumbersome so I like doing it exactly how you did it because drama in and then adjust the elevations later yeah take a look at this we got one that's below ground and that's okay Raz will still call anything to the right of that ineffective at that elevation so you can put them below ground that's there's no problem with that and that looks like it might even be inside so this one's not really going to be used but that particular example you're showing there would have I would have another question though which is hey can flow get over to the right of that or does it have to over top that Levy looking feature uh before yeah before it's it's so it's it kind of it's a good example of how adding and effectives can kind of build on themselves from a workflow standpoint you add them in for for a structure and then all of a sudden you realize you need to add them in for some floodplain geometry that you have it taken into account so it's an iterative process it takes a little bit of time but hopefully today's video is a good summary uh a high level summary of how ineffective flow areas work when they're used how to add them in and some some good things to consider when you're doing so yeah no um yeah so hope this helps people out um comprehend a little bit better the concept of ineffective flows it's always one of the more difficult things to teach somebody who's brand new tech grads and hydraulic modeling what ineffective flow means but if you're still not sure get out to the river look for those Eddy patterns and look for those Eddy lines that's where your ineffective flows get defined and the more you see that you see how water interacts around obstructions to flow and how it separates off the more you're going to be better at doing this in your models yeah all right I'll add two if you don't if you obviously get on the river regardless but another great way to kind of visualize how this is working is build 2D models maybe not have the site that you're trying to do but if you have the opportunity to to look at a 2d model run the full momentum set of equations and look at what the ineffectives are like because that's kind of like getting down the river you're seeing what the physics the the hydraulic physics would result in in terms of expansion and contraction for particular setups of bridges or blocked obstructions or culverts or whatnot it's a great way to have another way to visualize that yeah that was the first thing I thought when we talked about doing ineffective flows for the podcast today as well how can I visually demonstrate this oh let's just do some some 2D model stuff so you know I have this this test Flume that that I reuse for all sorts of things I was like ah let's just take that and I'll I'll dump some obstructions in there and we'll see how the flow goes around it and show where the ineffectives go so yeah it's a great tool you can use it to help you define where your cross sections go and where your ineffectives go then by all means yeah I use it cool well this has been awesome Chris thanks for walking folks through that uh just a couple quick reminders again keep an eye out for our live vodcast that we're going to have some time in the q1 of next year uh be great to get a bunch of people on that asking some good questions also if you're interested in applying for the internship at Kleinschmidt working with Chris and I and H H in Portland Oregon make sure you get your application in as soon as you can uh anything else Chris before we part for for the end of 2022. I just want to wish everybody a Happy New Year happy holidays to everybody out there um and keep an eye out for that um swag that we're gonna have soon it's going to be awesome I I've told you this many times and other people too Ben is that one of my life goals is to walk down the aisle of an airplane and see somebody with the uh full momentum podcast hat on or something I love it so where proudly hopefully hopefully in 2023 we'll we'll get there but anyway thanks for thanks for everybody who tuned in today uh this has been full momentum in HEC Raz podcast until next time [Music]

Channel: The RAS Solution

Views: 2,495

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Id: S-08OLSSDuQ

Length: 65min 1sec (3901 seconds)

Published: Mon Dec 19 2022