This was a fantastic demonstration! Thorough and covered various scenarios. Bravo! I always wondered what going through a culvert would be like. I'll take a note from the duck. thanks!
Powerful demonstration. I makes one fully understand open channel flow of water and I will use this as a demonstration to ,my students under the topic Open Channel flow and design in irrigation management course.
Do you think about the effects of the hydraulic jump after the bridge/culvert on scouring the stream bed-- I do fish passage work in the USA, and type one flow that you suggested as ideal for hydraulic conveyances tends to created waterfalls at the culvert outlets over time and prevents fish from migrating upstream, and significantly alters the original hydraulic design.
JBA Consulting thank you for responding! I am familiar with creating Downstream controls to Backwater the culvert, that is indeed one of the major design criteria I require of the engineers I contract to design my culverts. My biggest issue with the type 1 flow scenario demonstrated in the video is that creating supercritical flow through the majority of the Culvert Barrel effectively surpasses swim burst speeds of most migratory fish and creates velocity barrier. Back watering with a downstream where or natural control point to create Type 3 tranquil flow conditions can work, but in any situation where the stream is being forced into a smaller cross-sectional area then exist in the natural stream there's going to be sediment agradation and scour issues at the Inlet and Outlet. Are you familiar or with the stream simulation design principles that the US Forest service has developed?See this link for more info: www.conservationwebinars.net/webinars/stream-simulation-culvert-design-and-performance The most important criteria they posit is to design open bottom structures whenever possible, and if not to embed culverts significantly to ensure that a natural stream substrate is contiguous through the culvert. Because of our endangered salmon and other Aquatic species, there is increasingly of focus on using this stream simulation design principles when putting in culverts. Designing structures that mimic stream processes through the culvert to ensure adequate sediment mobiltiy Downstream and Aquatic organism passage up and down stream to increases ecological function and decreases catastrophic flood failure risk because sediment aggregation and scour are no longer an issue if the stream cross-sectional area is preserved throughout the culvert. Obviously cost increases a structure span increases, and this is the major roadblock to the implementation of this strategy! I would love to hear your thoughts on other more cost-effective ways to meet both of hydraulic and ecological goals of road/stream crossings. Thanks for this video it is very informative and helpful!
Hi Aditya, thanks for commenting. A mild slope is one where flow depth is greater than critical depth (i.e. where flow is subcritical). A steep slope is one where flow depth is less than critical depth (i.e. where flow is supercritical) A medium slope is one where flow depth is at or close to critical depth In terms of quantifying what slope values are (‘mild’, etc) it depends on several factors: flow rate, roughness, position of hydraulic controls. However, as a guide, a steep slope is 1 in 10 (10%) or steeper and a mild slope 1 in 100 (1%) or slacker. I hope that helps. Jeremy Executive Chairman of JBA Group
![Lp. Сердце Вселенной #60 РОЖДЕНИЕ ЛОЛОЛОШКИ [Финал] • Майнкрафт](http://i.ytimg.com/vi/YoR0pAV9FVQ/mqdefault.jpg)
When you added that first obstruction, the result was very weird (pun very much intended)! :P
Fantastic. I was having trouble visualizing the river before and after a weir was added. This clears it up nicely. Thanks for posting.
love it.. ive rarely seen so much thought in the design of bridges and weirs..thanks...
doc johnny
This was a fantastic demonstration! Thorough and covered various scenarios. Bravo! I always wondered what going through a culvert would be like. I'll take a note from the duck. thanks!
Thanks so much...could e explain what the flume plate is made of? Fiber glass or glass?
Thanks, it's an awesome and very complete explanation! Perfect for all us curious students.
Thank you Estefania, we are pleased you found it useful and best of luck with your studies
Greetings from ITCR, Costa Rica! :)
Powerful demonstration. I makes one fully understand open channel flow of water and I will use this as a demonstration to ,my students under the topic Open Channel flow and design in irrigation management course.
can you show me the Parshall flume demonstration
16:40 "not a very pleasant experience for the duck"
Is it possible to get a fully developed flow in this flume of short length ?
very useful video and btw I am currently using hydrology in practice by ROB LAMB..thank you
Kindly also discuss about calculations. How we will do calculations for this experiment?
Great experiment and very well demonstrated, Thank you!
Do you think about the effects of the hydraulic jump after the bridge/culvert on scouring the stream bed-- I do fish passage work in the USA, and type one flow that you suggested as ideal for hydraulic conveyances tends to created waterfalls at the culvert outlets over time and prevents fish from migrating upstream, and significantly alters the original hydraulic design.
JBA Consulting thank you for responding! I am familiar with creating Downstream controls to Backwater the culvert, that is indeed one of the major design criteria I require of the engineers I contract to design my culverts. My biggest issue with the type 1 flow scenario demonstrated in the video is that creating supercritical flow through the majority of the Culvert Barrel effectively surpasses swim burst speeds of most migratory fish and creates velocity barrier. Back watering with a downstream where or natural control point to create Type 3 tranquil flow conditions can work, but in any situation where the stream is being forced into a smaller cross-sectional area then exist in the natural stream there's going to be sediment agradation and scour issues at the Inlet and Outlet.
Are you familiar or with the stream simulation design principles that the US Forest service has developed?See this link for more info: www.conservationwebinars.net/webinars/stream-simulation-culvert-design-and-performance
The most important criteria they posit is to design open bottom structures whenever possible, and if not to embed culverts significantly to ensure that a natural stream substrate is contiguous through the culvert.
Because of our endangered salmon and other Aquatic species, there is increasingly of focus on using this stream simulation design principles when putting in culverts. Designing structures that mimic stream processes through the culvert to ensure adequate sediment mobiltiy Downstream and Aquatic organism passage up and down stream to increases ecological function and decreases catastrophic flood failure risk because sediment aggregation and scour are no longer an issue if the stream cross-sectional area is preserved throughout the culvert. Obviously cost increases a structure span increases, and this is the major roadblock to the implementation of this strategy! I would love to hear your thoughts on other more cost-effective ways to meet both of hydraulic and ecological goals of road/stream crossings.
Thanks for this video it is very informative and helpful!
6:56 head lost at bridge
8:33 with culvert
11:55 he missed!
Hello everyone, can someone please tell me what's the technical term for water tank in the video, it'd be much appreciated ^^
What are the dimensions or specific criteria to classify low slope, medium slope and large slope of
open channel flow? Briefly explain?
Hi Aditya, thanks for commenting.
A mild slope is one where flow depth is greater than critical depth (i.e. where flow is subcritical).
A steep slope is one where flow depth is less than critical depth (i.e. where flow is supercritical)
A medium slope is one where flow depth is at or close to critical depth
In terms of quantifying what slope values are (‘mild’, etc) it depends on several factors: flow rate, roughness, position of hydraulic controls. However, as a guide, a steep slope is 1 in 10 (10%) or steeper and a mild slope 1 in 100 (1%) or slacker.
I hope that helps.
Jeremy
Executive Chairman of JBA Group
this is too good , really beneficial
awesome video very well explained....
Very interesting thanks - A canoist
THANK YOU.
good ..
Thank you
Great experiment and very well demonstrated, Thank you!