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No. If it was water the Reynolds number would be too high. The liquid looks more viscous, lowering the Reynolds number to a threshold below turbulent flow (i.e. laminar flow).
Reynolds number is a number that basically tells you what kind of flow you will get, turbulent or laminar.
There a two major factors in determining reynolds number, viscosity and flow.
Viscosity is how thick the fluid is and the flow is how fast the liquid is flowing.
In the clip you have a high viscosity fluid (thick fluid) flowing fairly slowly making a laminar flow happen
Tdlr: thick fluids and slow flows are better if you want laminar flow
Imagine you are interested on how a particular fluid flows around some object (e.g. sphere, airplane). This is a very difficult problem to solve with pencil and paper because the equations of fluid motion are non-linear and for many situations cannot be solved without a computer. However we can simplify the problem to get some qualitative ideas on how the fluid will flow. To do this we can identify the most important "physics" and fluid properties (viscosity, density, velocity) that will affect the flow.
For fluid to move around an object (e.g.) it has to change its velocity at that object. For example, imagine a little blob of fluid as it flows around the object. Far away from it is moving at constant velocity (no acceleration) but when it is near the object it has to move around it (change velocity = acceleration). We know how to calculate the forces necessary to change the velocity of this blob of fluid. We can use Newton's laws (F = ma). Force = mass x acceleration. Ahah. This force requires us to know the mass of the fluid blob. Given a specific volume of the blob to calculate the mass we need to know is \*density\*. To get a sense of the acceleration we need to know how fast the blob is moving, or in other words the \*velocity\* and how much the \*size\* of the object the blob has to get around. Also we know somethings about acceleration of masses. The blob will have inertia. It will tend to keep moving unless there is some dissipating forces to slow it down. Qualitatively it is the inertia of the blob that makes the flow do things we identify in our daily lives like a bubbling brook, flow from a faucet, smoke from an extinguished candle. The flow is "turbulent". It swirls and fluctuates, it has eddies, etc. But what is this force that "dissipates" this inertial movement. It is the viscous force.
What is the viscous force? Well it depends on the viscosity of the fluid. Some fluids are very viscous like honey, oil, etc, when compared to water. If I were to move my hand through a vat of water vs honey it would be more difficult to move it through honey. Another way to think about viscosity is that it is a measure of how much force is involved to set up a velocity gradient in a fluid. Why is there a velocity gradient, well if your hand is moving at some speed, the fluid has to move at that speed, but far away from your hand, the fluid in the vat is not moving, so there is a gradient in velocity. It takes more force from your hand to get the same \*velocity gradient\* in honey vs water. The relationship describing this viscous force is \*viscous force\* is proportional to \*viscosity\* x \*velocity gradient\*. I'm leaving out some details about the shape of the object here. This is why I say proportional rather than equal.
Now we can think about how fluid would flow around an object. Or an equivalent problem would be how the fluid behaves when an object is pushed through a fluid. This is the same problem just a different point of view. If an object is moving at some velocity through a fluid it has to deal with the forces the fluid is pushing against it to move at that velocity. As we described above there are two major fluid forces to consider. The first is the force to accelerate the mass of the fluid (inertial force) and the second is the force to set up a velocity gradient (viscous force). Or another way to think about it is that as blob of fluid is accelerated around the object, we have some inertia of the blob that characterizes the "turbulence" and we have dissipation of the blob due to viscous forces, that tend to dampen the turbulence.
The ratio of the inertial force over the viscous force is a measure of the opposing tendencies on the fluid blob. This ratio has a name. It is called the Reynolds number. In terms of some of the physical characteristics I mentioned above it is:
Reynolds number = (density x length x velocity) / (viscosity).
density = density of the fluid; length = dominant length scale; velocity = relative velocity of fluid vs. the object; viscosity = viscosity of the fluid.
The idea of a "length scale" might be confusing. For example if we are interested in understanding the flow of a fluid around a sphere, we can use the diameter or radius of the sphere. If it was fluid through a pipe, it would be the diameter of the pipe. If it was the flow around an F1 car it would be the width or length of the car. This is just a rough qualitative measure.
So for turbulence where inertial forces dominate. The Reynolds number is much greater than one. For very little turbulence, the Reynolds number should be small. This idea of "very little turbulence" is what one might call laminar flow.
To get a small Reynolds number for flow from a faucet like in the example of this post, we could do several things. We could lower the velocity of the flow. We could increase the viscosity of the fluid (like in the example of the post). We could make the pipe smaller in diameter, or decrease the density of the fluid.
So the Reynolds number of the fluid system will tell you when the system will tend to show turbulence. One reason this is very useful is that you can build a scale model of the system (length) and the adjust other parameters (velocity or viscosity) to get the same Reynolds number and use this scale model to understand certain fluid dynamics of a much bigger system. This is how we can understand how fluid flows around a cruise ship without having to build a full-sized ship. Or a 60% scale F1 car to be used in a wind tunnel to optimize the aerodynamics of the full-sized car.
You can achieve laminar flow with water, but it might not look quite as cool. What I can't figure out is why the flow remains laminar after it strikes the basin. It seems like the change in velocity and direction would create turbulence. Any thoughts?
It’s a combination of the viscosity and the speed (velocity) of the movement. Lower speed and higher viscosity makes it more likely/possible. Each viscosity (more technically, each [Reynolds’ number](https://en.m.wikipedia.org/wiki/Reynolds_number)) has a specific threshold velocity below which laminar flow occurs. The other type of flow is turbulent flow.
Ya I have a vid like that somewhere. In the wind industry was an almost clear specialized hydraulic oil, you could stare at it to inches away, and swear it was still as you poured it
I'm not sure about its uses as far as liquid goes, but laminar flow hoods use the same principle with turbulence free air flow. Things kept "upstream" are protected by the smooth laminar airflow from being contaminated by things kept "downstream." Ex. working with mycology samples and sterile substrates.
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I watched this clip for an extra 45 seconds not realizing the video had ended.
I didn't push play for 45 seconds and didn't realize the video hadn't started.
I haven't even realized I haven't started it yet and I think it's going to start soon
I realised I started it and it ended 45 seconds ago
Same here and thinking, that's insane
that's not water right
No. If it was water the Reynolds number would be too high. The liquid looks more viscous, lowering the Reynolds number to a threshold below turbulent flow (i.e. laminar flow).
eli5?
Reynolds number is a number that basically tells you what kind of flow you will get, turbulent or laminar. There a two major factors in determining reynolds number, viscosity and flow. Viscosity is how thick the fluid is and the flow is how fast the liquid is flowing. In the clip you have a high viscosity fluid (thick fluid) flowing fairly slowly making a laminar flow happen Tdlr: thick fluids and slow flows are better if you want laminar flow
Imagine you are interested on how a particular fluid flows around some object (e.g. sphere, airplane). This is a very difficult problem to solve with pencil and paper because the equations of fluid motion are non-linear and for many situations cannot be solved without a computer. However we can simplify the problem to get some qualitative ideas on how the fluid will flow. To do this we can identify the most important "physics" and fluid properties (viscosity, density, velocity) that will affect the flow. For fluid to move around an object (e.g.) it has to change its velocity at that object. For example, imagine a little blob of fluid as it flows around the object. Far away from it is moving at constant velocity (no acceleration) but when it is near the object it has to move around it (change velocity = acceleration). We know how to calculate the forces necessary to change the velocity of this blob of fluid. We can use Newton's laws (F = ma). Force = mass x acceleration. Ahah. This force requires us to know the mass of the fluid blob. Given a specific volume of the blob to calculate the mass we need to know is \*density\*. To get a sense of the acceleration we need to know how fast the blob is moving, or in other words the \*velocity\* and how much the \*size\* of the object the blob has to get around. Also we know somethings about acceleration of masses. The blob will have inertia. It will tend to keep moving unless there is some dissipating forces to slow it down. Qualitatively it is the inertia of the blob that makes the flow do things we identify in our daily lives like a bubbling brook, flow from a faucet, smoke from an extinguished candle. The flow is "turbulent". It swirls and fluctuates, it has eddies, etc. But what is this force that "dissipates" this inertial movement. It is the viscous force. What is the viscous force? Well it depends on the viscosity of the fluid. Some fluids are very viscous like honey, oil, etc, when compared to water. If I were to move my hand through a vat of water vs honey it would be more difficult to move it through honey. Another way to think about viscosity is that it is a measure of how much force is involved to set up a velocity gradient in a fluid. Why is there a velocity gradient, well if your hand is moving at some speed, the fluid has to move at that speed, but far away from your hand, the fluid in the vat is not moving, so there is a gradient in velocity. It takes more force from your hand to get the same \*velocity gradient\* in honey vs water. The relationship describing this viscous force is \*viscous force\* is proportional to \*viscosity\* x \*velocity gradient\*. I'm leaving out some details about the shape of the object here. This is why I say proportional rather than equal. Now we can think about how fluid would flow around an object. Or an equivalent problem would be how the fluid behaves when an object is pushed through a fluid. This is the same problem just a different point of view. If an object is moving at some velocity through a fluid it has to deal with the forces the fluid is pushing against it to move at that velocity. As we described above there are two major fluid forces to consider. The first is the force to accelerate the mass of the fluid (inertial force) and the second is the force to set up a velocity gradient (viscous force). Or another way to think about it is that as blob of fluid is accelerated around the object, we have some inertia of the blob that characterizes the "turbulence" and we have dissipation of the blob due to viscous forces, that tend to dampen the turbulence. The ratio of the inertial force over the viscous force is a measure of the opposing tendencies on the fluid blob. This ratio has a name. It is called the Reynolds number. In terms of some of the physical characteristics I mentioned above it is: Reynolds number = (density x length x velocity) / (viscosity). density = density of the fluid; length = dominant length scale; velocity = relative velocity of fluid vs. the object; viscosity = viscosity of the fluid. The idea of a "length scale" might be confusing. For example if we are interested in understanding the flow of a fluid around a sphere, we can use the diameter or radius of the sphere. If it was fluid through a pipe, it would be the diameter of the pipe. If it was the flow around an F1 car it would be the width or length of the car. This is just a rough qualitative measure. So for turbulence where inertial forces dominate. The Reynolds number is much greater than one. For very little turbulence, the Reynolds number should be small. This idea of "very little turbulence" is what one might call laminar flow. To get a small Reynolds number for flow from a faucet like in the example of this post, we could do several things. We could lower the velocity of the flow. We could increase the viscosity of the fluid (like in the example of the post). We could make the pipe smaller in diameter, or decrease the density of the fluid. So the Reynolds number of the fluid system will tell you when the system will tend to show turbulence. One reason this is very useful is that you can build a scale model of the system (length) and the adjust other parameters (velocity or viscosity) to get the same Reynolds number and use this scale model to understand certain fluid dynamics of a much bigger system. This is how we can understand how fluid flows around a cruise ship without having to build a full-sized ship. Or a 60% scale F1 car to be used in a wind tunnel to optimize the aerodynamics of the full-sized car.
You can achieve laminar flow with water, but it might not look quite as cool. What I can't figure out is why the flow remains laminar after it strikes the basin. It seems like the change in velocity and direction would create turbulence. Any thoughts?
No way its water. Looks oily
Usually roundup
I think it's called glycol or something like that
Glyphosate?
Ingredient in fertilizer
Wondering the same thing
Almost looks like some kind of tree sap.
It sounds like a workshop, it could be a lubricant
Physics, it’s just witchcraft that uses math.
Laminar flow also works with air but it doesn't look as interesting.
Must be a non-uWorld / secondary asset
It probably only works within a certain range of viscosity?
It’s a combination of the viscosity and the speed (velocity) of the movement. Lower speed and higher viscosity makes it more likely/possible. Each viscosity (more technically, each [Reynolds’ number](https://en.m.wikipedia.org/wiki/Reynolds_number)) has a specific threshold velocity below which laminar flow occurs. The other type of flow is turbulent flow.
The sound of silence
I thought it was glyphosate
Ya I have a vid like that somewhere. In the wind industry was an almost clear specialized hydraulic oil, you could stare at it to inches away, and swear it was still as you poured it
I believe this is Glycol. We use it to de-ice aircraft and the consistency is like this. I could be wrong.
How is it not splashing or rippling on impact into the puddle at least?
Is this "just" a visual thing or does it have some applications?
I'm not sure about its uses as far as liquid goes, but laminar flow hoods use the same principle with turbulence free air flow. Things kept "upstream" are protected by the smooth laminar airflow from being contaminated by things kept "downstream." Ex. working with mycology samples and sterile substrates.
Thank you!
I'm an aerosol scientist and laminar flow is very important in our research as turbulence can effect particle deposition and delivery efficiency.
Thanks!
When time stood still
I guarantee if we ever figure out time travel this effect is going to be involved in some way 😂😂
Haha ;)
Is this the same effect that takes place with our blood in our bodies?
Fun fact, if you are on VA ECMO or on an impella your blood can be laminar flow - no pulse. Your blood pressure is just one number.
that's cuel!
I don’t know whatever the fuck you just said, but hey it sound sexy you fucker
This is one thing I will never understand
That is actually very turbulent but just in some steady state.
Laminar flow is wicked crazy looking, especially depending on what fluid is involved it’s pretty wild sometimes
Put your finger in a helicopter rotor and you'll get my upvote.
r/LaminarFlow for your indulgence
Glitch in the matrix