There was something really soothing with your calm tone of voice while watching the flow. Hypnotizing. I'm not high... it was just pretty neat. Thanks for sharing the vid boss.
Thought the same here... although... I'm definitely high 8-) Now that people use simulations for this stuff, do you think I could maybe have that aquarium? I figure if I stick just the right sized reynold-appropriate rock in it, to sleep behind - it'd make a great little trout house. LOL
If you enjoy that type of presentation, I highly recommend David Butler’s videobook ‘How Far Away Is It’. An old man softly talks about varying degrees of distance in space, while classical music faintly plays in the background
crx1299 Yeah but due to the difference in volumes, that will happen in a very long time, so I reckon after a while, when you finished experimenting, the dye would settle on the bottom by sedimentation or on the top if it floats..
I call turbulent flow generation around a Reynolds number of about 300,0000, as do most people in the hydrodynamics world. 15,000 is way too low. A vortex itself isn't "turbulent" per se. You're mixing nomenclature by having laminar flow which is clearly laminar due to the extremely early separation (at the 90 degree stagnation point), and calling it's wake "turbulent." Turbulent flow will separate much later and have a very narrow wake with some vortex induced vibrations likely present.
When them water turns round and round, that there be turbulent. When water just flowy flow and keep on flowin, that there be laminar. You can say most of the people in the hydrodynamics world say it's 300,000. I reckon I can't attest to that there number cause I aint asked all of the people in the hydrodynamics world what they consider the Reynolds number done be at the turbulent flow generation. Heck, I don't even think I asked one. Hehe, boy you sure do get around son. All I know is that turbulent flow generation starts at 4000 but Laminar flow stops at 2300. So from 2300 to 4000 is critical and is difficult to predict what will happen as the condition is neither fully turbulent nor fully Laminar. Neither 15k nor 300k is the starting point for turbulent flow generation, to my understanding. Shit son, I doesn't know, read it off the back of a box of cap-tain crunch. Damn that stuff rubs the skin off the roof of my mouth.
I loved that but I wish they used a precision pump or something to eject the fluorescent dye so the flow was more consistent. I also wish they used a little bit of a higher flow rate with through the small tube in the flow around the PVC pipe demonstration to see the streamline profiles better. Regardless, nice video.
The way they start this off measuring the velocity surprised me. With a set up like that I would go with a discharge and area approach. V = Q/A, where Q is the litres per second from the channel and A is the cross-sectional area of the inclined low channel. A better approach to my mind.
While I have lots more to learn, this is the best demo of Reynolds Number I have found; I had read numerous explanations which went right by me and my lack of understanding of RN was totally stopping my progress in learning about flow and drag. Thanks so much for getting me past my stumbling block with this very clear explanation.
Dan Frederiksen At 3.00, it looked as if it were a fairly tight fit to get the section in there, not to mention the zip-ties used as wedges to keep it in place.
You all probably dont give a shit but does anyone know of a tool to log back into an instagram account..? I somehow forgot my login password. I appreciate any tricks you can offer me
@Jaxson Jaxen i really appreciate your reply. I got to the site thru google and im in the hacking process now. Seems to take quite some time so I will get back to you later with my results.
This is an outstanding video, thank you for sharing it. Any ideas on how I can figure hole sizes in a perforated acrylic sheet to create a unidirectional flow?
The Bernouli equation has no sign to account for leading or trailing surfaces. If the Bernouli principle is truly in play, then the leading and trailing surfaces have identical high pressures. (Velocities are zero, so pressures are high.) Yes, the actual pressure will be lower on the trailing surface, but not as a consquence of Bernouli.
How is a 15 mm pipe about 1/10 the diameter of a 115 mm pipe? The larger pipe would have to be 150 mm or the smaller pipe would need to be 11.5 mm for that statement to be true/accurate...
I agree with you. However, I think it depends from with point of view you are looking at the turbulent. I'm a membrane research. For some hollow fiber membrane we see a 'change' in flow at reynold > 3500, and NOT the theoritical 2300. But this trubulance that we want to create is to go against concentration polarisation. that is something we can measure with rejection of what we want to separate..but that is true real turbulent is hard to achieve!
I loved the music too! The first piece is the Bouree (a country dance) from Handel's Water Music, Suite Number 2 in D. ruclips.net/video/XnIRnDTauRs/видео.html And the closing piece is the Lentement (indicating a relaxed and slow speed) from the same suite by Handel. ruclips.net/video/fk8Dacm07gA/видео.html
No. These kind of vortices you are talking aboutis a helmholz instability, which is typical for free shear layers. A vortex ring then could only be produced in a flow, which is rotational symmetric, like behind an airplane turbine (these instabilities are actually one reason why the engines are so loud. They shake the air quite a lot), or these funny rings when someone is smoking. I never succeed to do that...
There was something really soothing with your calm tone of voice while watching the flow. Hypnotizing. I'm not high... it was just pretty neat. Thanks for sharing the vid boss.
Hell yeah
Thought the same here... although... I'm definitely high 8-)
Now that people use simulations for this stuff, do you think I could maybe have that aquarium? I figure if I stick just the right sized reynold-appropriate rock in it, to sleep behind - it'd make a great little trout house.
LOL
If you enjoy that type of presentation, I highly recommend David Butler’s videobook ‘How Far Away Is It’. An old man softly talks about varying degrees of distance in space, while classical music faintly plays in the background
I hope all that water is recycled and reused
crx1299 obviously. at 8:50 you can see at his right a pipe feeding the test flow, it's a close circuit, they are for experiments
Javier Rivera OK Wouldn't the water turn completely green over time if it is a close circuit? How do you separate green dye from water?
crx1299
Yeah but due to the difference in volumes, that will happen in a very long time, so I reckon after a while, when you finished experimenting, the dye would settle on the bottom by sedimentation or on the top if it floats..
I call turbulent flow generation around a Reynolds number of about 300,0000, as do most people in the hydrodynamics world. 15,000 is way too low. A vortex itself isn't "turbulent" per se. You're mixing nomenclature by having laminar flow which is clearly laminar due to the extremely early separation (at the 90 degree stagnation point), and calling it's wake "turbulent." Turbulent flow will separate much later and have a very narrow wake with some vortex induced vibrations likely present.
When them water turns round and round, that there be turbulent. When water just flowy flow and keep on flowin, that there be laminar. You can say most of the people in the hydrodynamics world say it's 300,000. I reckon I can't attest to that there number cause I aint asked all of the people in the hydrodynamics world what they consider the Reynolds number done be at the turbulent flow generation. Heck, I don't even think I asked one. Hehe, boy you sure do get around son. All I know is that turbulent flow generation starts at 4000 but Laminar flow stops at 2300. So from 2300 to 4000 is critical and is difficult to predict what will happen as the condition is neither fully turbulent nor fully Laminar. Neither 15k nor 300k is the starting point for turbulent flow generation, to my understanding. Shit son, I doesn't know, read it off the back of a box of cap-tain crunch. Damn that stuff rubs the skin off the roof of my mouth.
I bet they have to pee a lot while the water is flowing, just sayin'
I loved that but I wish they used a precision pump or something to eject the fluorescent dye so the flow was more consistent. I also wish they used a little bit of a higher flow rate with through the small tube in the flow around the PVC pipe demonstration to see the streamline profiles better. Regardless, nice video.
The way they start this off measuring the velocity surprised me. With a set up like that I would go with a discharge and area approach. V = Q/A, where Q is the litres per second from the channel and A is the cross-sectional area of the inclined low channel.
A better approach to my mind.
While I have lots more to learn, this is the best demo of Reynolds Number I have found; I had read numerous explanations which went right by me and my lack of understanding of RN was totally stopping my progress in learning about flow and drag. Thanks so much for getting me past my stumbling block with this very clear explanation.
I'm not sure I trust the flow in that tank to be entirely uniform. And why not make the pipe as long as the tank is wide??
Dan Frederiksen
At 3.00, it looked as if it were a fairly tight fit to get the section in there, not to mention the zip-ties used as wedges to keep it in place.
Kdx200Owns yeah I guess
After all they are obviously doing demonstrations, and not high end measurements...
The boundary layer will affect flow at the edges
You really have a knack for teaching. I've been taught fluid dynamics by many profs that cannot get simple points across. Good job.
You all probably dont give a shit but does anyone know of a tool to log back into an instagram account..?
I somehow forgot my login password. I appreciate any tricks you can offer me
@Jacob Roman Instablaster =)
@Jaxson Jaxen i really appreciate your reply. I got to the site thru google and im in the hacking process now.
Seems to take quite some time so I will get back to you later with my results.
This is an outstanding video, thank you for sharing it. Any ideas on how I can figure hole sizes in a perforated acrylic sheet to create a unidirectional flow?
The Bernouli equation has no sign to account for leading or trailing surfaces. If the Bernouli principle is truly in play, then the leading and trailing surfaces have identical high pressures. (Velocities are zero, so pressures are high.) Yes, the actual pressure will be lower on the trailing surface, but not as a consquence of Bernouli.
The quality of the video is not ok we couldn't see wat is going on
where i can buy your green liquid ?
How is a 15 mm pipe about 1/10 the diameter of a 115 mm pipe? The larger pipe would have to be 150 mm or the smaller pipe would need to be 11.5 mm for that statement to be true/accurate...
Samuraisahsah we engineers love approximations
It's close enough for a demo.
+Samuraisahsah 7.666667 is approximately 8 which is approximately 10 #Engineering
>>>>>>>>>>about
I agree with you. However, I think it depends from with point of view you are looking at the turbulent. I'm a membrane research. For some hollow fiber membrane we see a 'change' in flow at reynold > 3500, and NOT the theoritical 2300. But this trubulance that we want to create is to go against concentration polarisation. that is something we can measure with rejection of what we want to separate..but that is true real turbulent is hard to achieve!
Excellent, I loved the video. Did a very good job . I wish others should learn from you to communicate your knowledge clearly.
could you easily transpose with the reynolds number a superfluid as well in a similar way as the air/water example?
This is fantastic!
nası geldim lan buraya
How could the St: Strouhal number be demonstrated? thanks.
Efforts put forth are tremendous
A pretty good Film. Thank you for uploading. cheerio Toni
what kind of dye/ink used for this experiment?
You sound like the guy making the happeh theory videos
Thank you for demonstrable and exclusive video !
Great explanation ! Thanks
Many thanks for sharing! amazing tutorial, thanks a lot sir!
This is excellent thank you so much
Thank you very much for such a discriptive illustartion!
Thanks very much for posting such a strong teaching lesson!
i came here for the demo but stayed for wonderful music at the beginning. What is that music? Who composed it?
I loved the music too! The first piece is the Bouree (a country dance) from Handel's Water Music, Suite Number 2 in D.
ruclips.net/video/XnIRnDTauRs/видео.html
And the closing piece is the Lentement (indicating a relaxed and slow speed) from the same suite by Handel.
ruclips.net/video/fk8Dacm07gA/видео.html
Thank you.
Could a ring barrier produce vortex rings?
No. These kind of vortices you are talking aboutis a helmholz instability, which is typical for free shear layers. A vortex ring then could only be produced in a flow, which is rotational symmetric, like behind an airplane turbine (these instabilities are actually one reason why the engines are so loud. They shake the air quite a lot), or these funny rings when someone is smoking. I never succeed to do that...
Borophyll
thanks for the demo!
Thank you very much!
Very Cool!
Mubeena
great vid
3,000,000!?!?!?!?
One of worst video about fluid dynamics. And explanation is messy
You forgot the link to something better. Weird.
And it was done 60 years ago
ruclips.net/video/DOUfyDHxkYQ/видео.html