Top quality material; thanks very much. At 17:52 I was a little bit confused about the idea of deforming a square into a rectangle because I was imagining a rhombus, but I guess I was overthinking there.
Hi. I just couldn't understand properly what no-slip condition exactly is. But you made it clear now - thanks to your wonderful explanation. I just have one question - is the 'dust on the car hood' example a valid example? I'm asking because dust is not a fluid. So my assumption so far is that you just used this example/figure to better explain the concept of no-slip condition. Please clarify. Thank you once again. :)
Dust is small solid particulate matter, NOT a fluid. If there was slip at the surface -- i.e., surface fluid velocity equal to the freestream velocity -- then you might expect these small solid dust particles to be blown away. But they do not, because the dust particles sit in a very low velocity region, due to the no-slip condition. The smallest particles sit in a low velocity region well inside the so-called velocity “boundary layer”.
I'm not sure which part of this video you are specifically referring to. Here is a general answer. The fluid "sticks" to the surface i.e., the no slip condition. If the fluid above a stationary surface is moving (because of a pump or fan, for example), the fluid's viscosity will decrease (to zero) as you approach the surface. It's the internal viscous shear forces in the fluid, which opposes fluid motion, that slows the fluid in the near wall region. So, to answer your question, it is both effects. I hope that helps.
So, hypothetically speaking, even if there doesn't exist 'no-slip' at the bottom surface ( but the fluid sticks to the top surface) there would be a velocity gradient in the fluid, solely because of the internal friction between them. Am I right, professor?
Lol. I wonder if ketchup manufacturers take into account the thixotropic properties of ketchup when designing the bottle. Or asked differently, is it possible to design a bottle so that ketchup flows more evenly/easily?
All the videos (and pdf downloads) for this introductory Fluid Mechanics course are available at: www.drdavidnaylor.net/
I like the dusty car example. 😅
Great Videos and Work. Thank you from Germany
Glad you like them!
Top quality material; thanks very much. At 17:52 I was a little bit confused about the idea of deforming a square into a rectangle because I was imagining a rhombus, but I guess I was overthinking there.
I think the deformed shape is a rhombus.
35:08 Probably misquoted: "Shake shake shake that old sauce bottle. None will come, and then a lot'll."
Hi. I just couldn't understand properly what no-slip condition exactly is. But you made it clear now - thanks to your wonderful explanation. I just have one question - is the 'dust on the car hood' example a valid example? I'm asking because dust is not a fluid. So my assumption so far is that you just used this example/figure to better explain the concept of no-slip condition. Please clarify. Thank you once again. :)
Dust is small solid particulate matter, NOT a fluid. If there was slip at the surface -- i.e., surface fluid velocity equal to the freestream velocity -- then you might expect these small solid dust particles to be blown away. But they do not, because the dust particles sit in a very low velocity region, due to the no-slip condition. The smallest particles sit in a low velocity region well inside the so-called velocity “boundary layer”.
@@FluidMatters Got it! Thanks a lot!
Just wanted to ask, would these videos still help for Aerospace students at Ryerson?
A first course in fluid mechanics is mostly the same material, regardless of the branch of engineering.
@@FluidMatters thank you!
Is it the no slip condition that causes the velocity gradient, professor or the internal shear stresses?
I'm not sure which part of this video you are specifically referring to. Here is a general answer. The fluid "sticks" to the surface i.e., the no slip condition. If the fluid above a stationary surface is moving (because of a pump or fan, for example), the fluid's viscosity will decrease (to zero) as you approach the surface. It's the internal viscous shear forces in the fluid, which opposes fluid motion, that slows the fluid in the near wall region. So, to answer your question, it is both effects. I hope that helps.
So, hypothetically speaking, even if there doesn't exist 'no-slip' at the bottom surface ( but the fluid sticks to the top surface) there would be a velocity gradient in the fluid, solely because of the internal friction between them. Am I right, professor?
I meant internal resistance between the fluid layers, alone, sir.
Nice work thx. from China!😘
Lol. I wonder if ketchup manufacturers take into account the thixotropic properties of ketchup when designing the bottle. Or asked differently, is it possible to design a bottle so that ketchup flows more evenly/easily?
I don't know. Apparently it took until 1991 to invent the upside down ketchup bottle, with the lid on the bottom. So don't hold your breath. ;)
Awesome explanation… loved it
Glad it was helpful!
carry on sir.it is more efficacious video for me
thank you very much
What text book are you referring to please? Thank you for your excellent lectures.🙏🏽
We use Fluid Mechanics by F.M, White.
Thank you very much professor Naylor.