I usually don't comment on videos, but you sir are an amazing teacher and by far the only person I have come across who can intuitively explain and simplify a complicated topic like fluid mechanics!
Absolutely brilliant teaching. I have been stumped in a 4th year undergrad class and you have managed to straighten it out within 30 minutes of your lectures. I dont leave comments often but I wanted to send a thank you for all the fluids students that take this course. All love from Toronto, Canada
Sir, Navier-Stokes helped me solve a problem I use, or wish I used, every day. If I take the straw out of my milkshake most of the way I can drink a milkshake through a straw. So the deeper the straw is the more vac is required. That's basically made me a wizard to every 7 year old. I BARELY only get pieces of this every time I watch but I get a little better every time. I won't be happy until I can calculate the angle of a pipe needed for a given amount of fluid with a known lighter than air vapor that needs to travel opposite the flow of more dense fluid. Or any one of the other variables given the other known conditions. So think of a safety situation in a lower budget developing nation, liquid needs to go down but its vapor needs to go up in the same cylinder with gravity only.
Who else is watching these his videos during the Lockdown.. Here in African we don't have the online resources at home so the lecturers are just sending notes and we are getting a lot of help from these guys even though our data is expensive
I can't believe how easy you've made it sound. Tomorrow's my exam and I had almost given up on these equations. Watching your 'how to apply N-S equations' just once has made everything so clear for me. Thank you. Allah bless.
at 4:00, I'm confused how you took the integral of the right hand side without any "dx" or "dz" present. I thought a derivative was necessary for an integration?
Andy, what is s clock? I asked myself several times today. Andy taught me to think more about the time, just like the linkin park song. Shana was a math kid like me but never fell into the trap. Andy is helping me understand my childhood.
I learned positive lessons at k state but only wanted 1 semester. K state faculty taught excellent lessons! They are a great school and I learned what I wanted to learn!
+zawette he didn't show it explicitly, but he basically just multiplied both sides by dr, thus getting rid on the 1/dr on the left side leaving d(r*dvz/dr) = (.....) dr
what an awesome series, really quite interesting and I was able to follow easily as well. Very good way of teaching complex subjects you have going there kind sir.
I wish my school would hire you as our Fluid Mechanics Professor, I'd have so much more motivation to study and pay attention because you simplify these topics so well.
I thought this was awesome. You took a basic problem and from first principles you were able to demonstrate how flow rate in a pipe works, generically.
Excellent explanation. As you discussed that we have to find the driving forces (pressure, shear, and gravity). If we get driving force is gravity or shear How could we deal with that? Thank
I want people to realize that Andy Thompsons defense of my LinkedIn account was a huge homework assignment. I wanted to learn lessons about electronic free speech at k state and that's what Andy Thompson protected and served.
Great video series. I wonder if you couldn't choose vz'(0) = 0 as your BC. I believe that is equivalent to what you are saying by vz(0) = finite. I think this BC is mathematically more rigorous than vz(0) = finite. vz'(0) = 0 saying there is symmetry about the z axis, and vz therefore needs to be a smooth function at r=0.
I have a qusetion, if the pressure is unknow at the inlet but the velocity is known. In this case, how will this problem be solved? Because in this case it seems that viscosity has inverse relationship with the velocity, however, when viscosity is not affecting the velcoity in pipe when the velocity is given as inlet condition in COMSOL
+Matt Peiffer You have disabled replies, so I can't respond directly. But if you happen to see this, then here is the explanation: The N-S equations are conservation of momentum equations, essentially they are force balance equations. The terms on the left hand side of his equations are acceleration terms and the terms on the right hand side are forces. The problem here is a viscous flow problem, therefore it isn't just P*A=m*a as you suggest, but there is also viscous drag (i.e. the term with mu in front). So no, you would not expect the velocity to go to infinity anywhere.
Thank you for the video. You explain the concepts very clearly. Just one question. In the last part of this video, are the integration limits rigth? Shouldn´t they be ranging between a and (-a) to cover the hole section of the pipe? Thank you
He is integrating over the area, r dr dq (dq is dtheta, I cant type the theta). Vz does not depend on q, but the area does, using a whole rotation as limits (0 to 2pi) that adds another 2pi hence the dA=2pi*r*dr. Integrating the whole rotating is already covering the pi to 2pi part or the negative r = -a to 0. Another way to do this would be to do half a rotation (q= 0 to pi, losing a factor 2) and diameter ( -a to +a, gaining a factor 2).
15:24 The viscosity of the drink is also often a factor when it comes to places that sell dairy shakes, fruit smoothies and the like. Although things are not directly comparable because dairy shakes are frequently non-Newtonian in nature, the dairy shake straw is often considerably greater in diameter than a corresponding soft drink straw to compensate for a considerably higher viscosity. Hold a and L constant and relate Q to delta-P divided by mu (which is much higher for the dairy shake/smoothie than it is for any "fizzy drink").
why even mess around with integrating to find volumetric flow rate? You could just use the boundary conditions to find the max and min velocities using the velocity profile, add them together and divide by 2, then multiple it by pi*r^2... gets the same answer
I'm pretty sure that assumes a linear velocity profile. Averages don't work on non-linear functions, which explains the need for the integral over the function.
Hold the phone. I have a problem with this whole thing. I've watched the videos many times and gone through my work many times and I think I'm right in saying: this isn't a steady state scenario if you say V_z is finite. If you say C_2 is 0, then the forces don't balance out. You end up with a constant pressure difference. Since we know F=ma (or P*A=ma in this case), the fluid will be accelerating, and not steady state. It totally makes sense that ln(0) should explode to negative infinity. If the fluid were allowed to accelerate, it's velocity would also reach infinity. If you want a steady state scenario, there can be no pressure drop component unless it's balanced by another force.
You have restored my faith in teachers of complex subjects!!
I usually don't comment on videos, but you sir are an amazing teacher and by far the only person I have come across who can intuitively explain and simplify a complicated topic like fluid mechanics!
Absolutely brilliant teaching. I have been stumped in a 4th year undergrad class and you have managed to straighten it out within 30 minutes of your lectures. I dont leave comments often but I wanted to send a thank you for all the fluids students that take this course. All love from Toronto, Canada
I like your voice Victor, it's very calm and confident. Thank you for your videos, I learned a lot.
i can not thank you enough for these precious videos i was completely lost in this subject and u saved me thank you so much !
Simply mind blowing. Idk how I completed all the videos on this playlist in a single sitting. Awesome explanation. Thanks a lot !!!!
man I am dancing in joy such great videos wacthed all 4 part feeling confident for todays test instead of being confused like before
Sir, Navier-Stokes helped me solve a problem I use, or wish I used, every day. If I take the straw out of my milkshake most of the way I can drink a milkshake through a straw. So the deeper the straw is the more vac is required. That's basically made me a wizard to every 7 year old. I BARELY only get pieces of this every time I watch but I get a little better every time. I won't be happy until I can calculate the angle of a pipe needed for a given amount of fluid with a known lighter than air vapor that needs to travel opposite the flow of more dense fluid. Or any one of the other variables given the other known conditions. So think of a safety situation in a lower budget developing nation, liquid needs to go down but its vapor needs to go up in the same cylinder with gravity only.
Who else is watching these his videos during the Lockdown.. Here in African we don't have the online resources at home so the lecturers are just sending notes and we are getting a lot of help from these guys even though our data is expensive
these videos are single handedly saving my grade
If all teachers were as good as you, we would be 100 years further into the future. Congratulations, God bless you.
This is pure gold! Thanks professor prof. Ugaz!
I can't believe how easy you've made it sound. Tomorrow's my exam and I had almost given up on these equations. Watching your 'how to apply N-S equations' just once has made everything so clear for me. Thank you. Allah bless.
Thank you sir!!! You are Awesome!!!
Whoa! Thanks for the journey from conservation of momentum to this point! Great videos.
Sir, I am so grateful for your videos on fluid mechanics. It has given an in-depth understanding to the Navier Stokes equation.
Thanks
This series explains things a lot better than lecturers did at uni
I think my professor watches these videos before his lecture
10 years ago!! Such a great explanation, thank you so much
I dont understand at 3:36 - why doesn't he bring the r attached to dvz/dr to the right hand side in the beginning to integrate over dr??
Good job. Very clear and step by step explanation.
Your explanation is so clear. Thanks
Thanks. That is a great way of teaching a very difficult subject. Excellent tutor.
with the straw's example at the end you've majestically explained Poiseuille flow : D. Great!
Today I learnt what my university professors couldn't teach properly. Thank you very much for these videos Sir.
Excellent set of lectures.
at 4:00, I'm confused how you took the integral of the right hand side without any "dx" or "dz" present. I thought a derivative was necessary for an integration?
he is integrating both sides with respect to r, so he can simply integrate the right hand side using the power rule
I really appreciate this amazing work that you have done for us. Thank you so much!
Andy, what is s clock? I asked myself several times today. Andy taught me to think more about the time, just like the linkin park song. Shana was a math kid like me but never fell into the trap. Andy is helping me understand my childhood.
Thank you so much for sharing. Greetings from Panama 🇵🇦
This series was great -- thank you!
I learned positive lessons at k state but only wanted 1 semester. K state faculty taught excellent lessons! They are a great school and I learned what I wanted to learn!
you just saved my life wih the first excercise thank you so much!!!
You integrate both sides when you start solving the ODE, but how come you integrate the right side without a dr factor?
+Eichro did anyone figure this out
+zawette he didn't show it explicitly, but he basically just multiplied both sides by dr, thus getting rid on the 1/dr on the left side leaving d(r*dvz/dr) = (.....) dr
He integrated both sides with respect to r. Mathematically, whatever you do to the right hand side should be done to the left hand side.
what an awesome series, really quite interesting and I was able to follow easily as well. Very good way of teaching complex subjects you have going there kind sir.
Good job Victor
Keep the good work
Loved the series! Great work..
Thank you very much Mr.Ugaz
I wish my school would hire you as our Fluid Mechanics Professor, I'd have so much more motivation to study and pay attention because you simplify these topics so well.
I thought this was awesome. You took a basic problem and from first principles you were able to demonstrate how flow rate in a pipe works, generically.
Excellent explanation. As you discussed that we have to find the driving forces (pressure, shear, and gravity). If we get driving force is gravity or shear How could we deal with that? Thank
Nice explanation...Very much detailed and helpful.
thank you so much man you are better teacher i wish you the best
Good work man.Thank you.
Amazing Video!!! Thank you so much
Thank you sir. Exactly what i was looking for.
Thank you! God bless you Sir!
amazing video thank you!!
thank you so mucho for share your knowledge!!!
MUITO BOM! AJUDOU IMENSAMENTE. Professor, muito obrigado!!!
These videos are amazing!! Do you have practice problems anywhere on your channel?
Thanks a lot! You explained it very well!!!
I want people to realize that Andy Thompsons defense of my LinkedIn account was a huge homework assignment. I wanted to learn lessons about electronic free speech at k state and that's what Andy Thompson protected and served.
You sir, are a genius! Also you sound like Christopher walken.
i feel like a pro in fluid mech now! thanks heapss
Andy Thompson understood my conception of internet free speech and advocated for its right to exist.
thanks a lot
great explaintion
Great video series. I wonder if you couldn't choose vz'(0) = 0 as your BC. I believe that is equivalent to what you are saying by vz(0) = finite. I think this BC is mathematically more rigorous than vz(0) = finite. vz'(0) = 0 saying there is symmetry about the z axis, and vz therefore needs to be a smooth function at r=0.
God bless you!
I have a qusetion, if the pressure is unknow at the inlet but the velocity is known. In this case, how will this problem be solved? Because in this case it seems that viscosity has inverse relationship with the velocity, however, when viscosity is not affecting the velcoity in pipe when the velocity is given as inlet condition in COMSOL
thank you very much dear professor
what if pipe is vertical? can we omit rho g from z direction? or we should add it too with minus sign ?
omg thank you very much you saved my life
u r my life saver
It's great! Thanks teatcher :)
about the C2, as the pressure drop is defined as a negative value, C2 is also negative but it is vary that Vz at r=0 is negative. I am confused why
Thank you so much! ❤️❤️❤️❤️👏🏻👏🏻👏🏻👏🏻
+Matt Peiffer You have disabled replies, so I can't respond directly. But if you happen to see this, then here is the explanation: The N-S equations are conservation of momentum equations, essentially they are force balance equations. The terms on the left hand side of his equations are acceleration terms and the terms on the right hand side are forces. The problem here is a viscous flow problem, therefore it isn't just P*A=m*a as you suggest, but there is also viscous drag (i.e. the term with mu in front). So no, you would not expect the velocity to go to infinity anywhere.
Thank you! helped a lot
Thank you for the video. You explain the concepts very clearly.
Just one question.
In the last part of this video, are the integration limits rigth? Shouldn´t they be ranging between a and (-a) to cover the hole section of the pipe?
Thank you
He is integrating over the area, r dr dq (dq is dtheta, I cant type the theta). Vz does not depend on q, but the area does, using a whole rotation as limits (0 to 2pi) that adds another 2pi hence the dA=2pi*r*dr. Integrating the whole rotating is already covering the pi to 2pi part or the negative r = -a to 0.
Another way to do this would be to do half a rotation (q= 0 to pi, losing a factor 2) and diameter ( -a to +a, gaining a factor 2).
Superiorer Thank you
Thanks a lot sir for the clear explanation :)
Thanks alot🤗
Beautiful
Thank you so much!
you can also use a double integral with respect to r and theta and get the same answer but your approach was clever
How to find the volume flow rate for concentric pipe having 0.012 mm clearance
Excellent!!! Thank you!!! :)
Thank you so much
Hi, I think we B.C we can use: dv(r=0)/dr = 0 instead of r=0, V=finite. Thanks.
really helpful!
EXCELLENT
Thanks a lot!
Faith in Fluid Dynamics Restored. #om
What’s I’ve been looking for
15:24 The viscosity of the drink is also often a factor when it comes to places that sell dairy shakes, fruit smoothies and the like. Although things are not directly comparable because dairy shakes are frequently non-Newtonian in nature, the dairy shake straw is often considerably greater in diameter than a corresponding soft drink straw to compensate for a considerably higher viscosity. Hold a and L constant and relate Q to delta-P divided by mu (which is much higher for the dairy shake/smoothie than it is for any "fizzy drink").
What is the unit of Q? I get it to become very strange with (m^2 * kg)/s, but the area should already be taken in account for..?
Also is the funny u, mu, viscocity or kinematic or dynamic viscocity?
Why was ln(0) not 1 and instead negative infinity?
it's rather ln(1) that is zero but ln(0) is infinity, just check the ln curve online
ln(x) means 'e' to what power equals 'x'
For 'e' to approach 0 the value of 'x' would have to be negative and infinitely large
great thanks.
Thx!
Tnks sir !!!
gud work
thousand "thank you"
you are fucking AWESOME !
Sorry I meant the WHOLE section of the pipe.
thannnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnks alot sir
why even mess around with integrating to find volumetric flow rate? You could just use the boundary conditions to find the max and min velocities using the velocity profile, add them together and divide by 2, then multiple it by pi*r^2... gets the same answer
I'm pretty sure that assumes a linear velocity profile. Averages don't work on non-linear functions, which explains the need for the integral over the function.
Alek Roulston yes, he mentions it's actually a parabolic curve at 8:10
i owe you my lyf
This mornings message at Armstrong chapel we need the lord is very controversial for some people.
Hold the phone. I have a problem with this whole thing. I've watched the videos many times and gone through my work many times and I think I'm right in saying: this isn't a steady state scenario if you say V_z is finite. If you say C_2 is 0, then the forces don't balance out. You end up with a constant pressure difference. Since we know F=ma (or P*A=ma in this case), the fluid will be accelerating, and not steady state. It totally makes sense that ln(0) should explode to negative infinity. If the fluid were allowed to accelerate, it's velocity would also reach infinity. If you want a steady state scenario, there can be no pressure drop component unless it's balanced by another force.
It is balanced by another force: the shear force tau = Force / Area of Contact
I wish you were my teacher, it would be more motivating.