Fluid Mechanics: Buoyancy & the Bernoulli Equation (5 of 34)

[@razorhxh7371]

This professor is the greatest. He should teach other professors how to teach a course.

[@151kkk]

Thank you so much! Our professor just opens up a big chunk of equation on the slide. He tells us to write it down and he gets angry if we ask a question. He just says 'its on the slide if you read it you'll get your answer.' I wish my professor could teach like you. You are very dedicated to your job. I wish you all the best!

[@CPPMechEngTutorials]

You're welcome!

[@wilsonmujang1770]

Same goes to my lecturer. He can't even explained how it's work and the concept.

[@sudetoprak6747]

dersi verdinmi şuan :D

[@muhammedeminural3333]

Bizim hocayı özetledin, hatta soruyu ben sormuştum sınıfta, acaba aynı hocadan mı alıyoruz diyeceğim ve şimdi yazarken farkettim 3 yıl önce yazmışsın :D

[@crazyworld3078]

You have a gift.. 💜 💜 One of the best teachers I've ever seen, the professor in my university just talk like a parrot doesn't describe the basic but just gives the equations, I have exams tomorrow and I was lost.. You saved me, thank you.. You are a great teacher.. Stay healthy and happy.. Your students are the luckiest to have you.. 💜 💜 💜 💜

[@CPPMechEngTutorials]

They certainly are. :D

[@mini_Ru]

I felt so stupid learning from my professor i didn't understand anything not even from the book, and then i found you and now everything is so easy .... Thank you you made me not want to quit

[@CPPMechEngTutorials]

We understand what you wrote. Keep working at engineering!

[@shalawali9836]

You may have created these videos to improve your canal but I think they make justice on earth. Thanks for your hard working.

[@CPPMechEngTutorials]

We made the videos to help out students and students around the world. The internet is an amazing tool. :)

[@Hindi_poetry]

@@CPPMechEngTutorials god bless u all ,, all the team which work behind this series of lecture lots of love ,,best hope ,prosperity and peace to u all guys ,,great job thank you

[@jong7513]

This was great. We need to clone this guy.

[@RDayan932]

Why does the free surface have a velocity of 0 at 1:00:00 in? wouldn't the water be moving downward since the water is falling out the bottom?

[@hootcheetoh3729]

Why didn't the professor assume exit pressure to be atmospheric Pressure at 14.7 Psi

[@pananaweKing]

U save me although i got 3 hrs before exam this means a lot for me. i fully understand what fluid talk about now. come at me wherever u want test paper XD

[@crankfrank3274]

Dr John Biddle is phenomenal

[@destro4450]

Thank you very much it a blessing to havefound this channel

[@larrya.4647]

This guy is a LEGEND

[@rllrll9512]

I hated this lectures for the purpose of revision only ( graduated already). Too much parameters and equations in each class. But i cannot ignore his talent in teaching.

[@GyeonghunPyeon]

베르누이 방정식을 경험적으로는 이해를 하고 있었습니다. 또 최종적인 식도 알고 있었지만 그 유도에 관해서는 모르고 있었습니다. 이 영상 덕분에 베르누이 방정식의 유도를 자세히 알게 된 것 같아 기분이 좋습니다.

[@alejandrovillarreal7975]

At 1:00:13 where does the 144 come from?

[@theefficentpiggie8577]

great lectures... Where does the 144 come from in the final example. 1:01:00

[@CPPMechEngTutorials]

There are 144 square inches per 1 square foot.

[@matthewmolinar]

this man is a god

[@johnpaulkiggundu9473]

Thank you very much Mr.Biddle This was very good content and you've delivered it ultimately

[@CPPMechEngTutorials]

You're welcome!

[@rtrt2889]

Biddle is the greatest!

[@vivekashish7897]

Plz explain at stagnation point v is 0 then why take the dynamic pressure term

[@catherinesc88]

i can't differentiate between the partial differential and differential @_@

[@CPPMechEngTutorials]

Can you provide a timestamp where you are getting confused?

[@scott337]

@@CPPMechEngTutorials @27:00 wthe equations on the right side board, you seem to change between partial and non partial differentials for no reason

[@MrHellsing1055]

56:13 Someone just made a sale on eBay (^:

[@markmaldonado7044]

Why did he multiply the pressure at point 1 by 144?

[@CPPMechEngTutorials]

+Mark Maldonado Please provide the time where you see this. It is likely due to a conversion from psi to psf.

[@jonathansnow6254]

Its right at 1:00:05

[@CPPMechEngTutorials]

Yup... looks like a conversion from psi (commonly used in industry) to psf. The specific weight and all the heights use feet. Aren't British/American units fun??

[@syakirazmi5038]

Yeah really fun. Feels bad for engineers in america to have to use imperial system.

[@MrHellsing1055]

Unit conservation in the wack system of measurement. 144 cm ^2 / 1 ft ^2

[@evaristogabriel8208]

why did we multiply 10 by 144?

[@jonathansnow6254]

Just out of curiosity, why is the differential area around 22:00 (dn)(dy) instead of (dn)(ds)? Also, thanks for the great videos.

[@CPPMechEngTutorials]

Force is pressure times area. The area over which the pressure acts is dn times dy (out of the board). If we were examining the pressure force at the top of the fluid element we would use dn ds as the area.

[@dianafregoso-sanchez9239]

Thank you for asking.

[@dianafregoso-sanchez9239]

@@CPPMechEngTutorials Thank you for answering.

[@ameliadilley5019]

for the sum of forces in the S direction, why is there delta infront of m x s?

[@3627336leo]

why the point 2 pressure is equal to atmosphere pressure? why not to analysis the normal line pressure?

[@dombadger2531]

Thank you very much for the video! I have a few trivia questions. 20:30 Does a_n(acceleration normal to the streamline) exist? According to the definition, velocity vector is tangent to streamline, which means zero velocity normal to the streamline, thus no acceleration normal to the streamline (a_n=0) 41:50 why streamlines are defined as "in a steady flow field"? I think that's different from the original definition of a streamline. 59:00 How to prove that point 1 and point 2 are on the same streamline?

[@ΚουρήςΆγγελος]

there is accelaration normal to streamlines and that is becouse the velocity is vector quantity so when there is change in orbit even if you dont change the |velocity| you will have accelaration. A real life example is when you make a big turn with your car and even if you have steady velocity you can fell the accelaration your car does. Sorry for my english i hope i helped you.

[@farhanshaikh8837]

20:30 acceleration exist as the particle along the streamline will change it's direction 41:50 its Steady flow flied, but the Particle should be at steady state while applying the Bernoulli equation( obviusly in reality its particle should be moving... steady state of particle is just an assumption) 59:00 I'm not sure.. Itheory

[@Krypt-yb7jd]

In the problem solved at the very end of the lecture, How can points 1 and 2 be considered as part of the same streamline? , which is a pre-requisite for applying Bernoulli's theorem.

[@CPPMechEngTutorials]

Good question. You have to imagine that a small chunk of fluid slowly drifts toward the inlet of the pipe. As it descends, the pressure changes but velocity barely changes. However, as it nears the inlet of the pipe, its velocity will increase more and more. The Bernoulli equation is a special limiting case of the conservation of energy equation. It might make more sense when looking at the more general form of the equation (see the lectures on pipe flow).

[@Krypt-yb7jd]

Thank you!

[@UwinIquit]

Had a quiz question regarded if the Bernoulli equation is a case of the conservation of energy equation. The answer was false because it is viewed as conservation of mechanical energy.

[@vinr1187]

@33.35 = I am getting confused with the direction of the force. We use ( P+change in P) as positive in the positive s direction but looking at the timestamp it's the opposite as the arrow pointing rightward is showing as negative where I think it should be positive ? Please help.

[@ogheneruonainkori8067]

I don't know if you still need this tho but here goes nothing.. First d direction only shows how the Pressure forces act on The differential element.. The magnitide (P+ dP) is bigger still than (P - dP) .. This verifies the fact that the Pressure increased over a change. Only that this bigger pressure seems to act towards negative x- axiz.. Because pressure is & must be compressive on an element.

[@hari.santoso]

A question : (last example) Why is flowing into the atmosphere causes P2 to be 0?

[@justinkeszthelyi1862]

He could have left it P2 as atmospheric pressure, but would then have to use the absolute pressure instead of gauge pressure for P1. They would wind up canceling each other out regardless. He essential set the pressure datum Patm=0

[@hari.santoso]

@@justinkeszthelyi1862 Well. Okay. Thanks for the answer

[@chemicalengineeringbd7614]

Thank you legend

[@ex.martian]

Thank you sir!

[@angrycloudofdogfood7128]

Thank you !

[@dremr2038]

14:03 - 55:00

[@DRoque14]

Why did the professor consider at point 2 the pressure to be zero and not to be the atmospheric pressure? Sorry for my english.

[@OsamaMohamed-nt3mk]

we deal with the pressure to be the Gage pressure (the pressure at point 1 is a Gage pressure ), so if u considered the pressure at point 2 to be the atmospheric pressure, then the pressure at point 1 will be the absolute pressure and u have to add the atmospheric pressure to it. as P(abs) = P(Gage) + P(atm)

[@DRoque14]

Thank you a lot!

[@OsamaMohamed-nt3mk]

u r welcome :)

[@DRoque14]

Osama Mohamed just one more question, hope you can answer me. In linear momentum equation, when we consider gauge pressure to calculate the forces done by pressure, we can cut the term of the force of weight? Thanks again.

[@OsamaMohamed-nt3mk]

i'm sorry, i haven't studied momentum equation yet.

[@deborahnguy]

what textbook did he use?

[@SeekTheTruthAndTruth]

Hi i was also wondering same :)

[@azramangp]

Fundamentals of Fluid Mechanics, 7 Edition 2012 from Munson & Young. He noted in first lecture

[@ameliadilley5019]

in the example, for p1 why is 10 x 144?

[@baqik]

could you figure it out why?

[@baqik]

oh ok they mentioned about that at the comments below

[@varunsubramanian5484]

its way easier to derive bernoulli equation form the energy equation , instead of doing all this

[@Octolev]

good stuff

[@CPPMechEngTutorials]

Thanks.

[@tajpa100]

Professor, I did not understand why dPs=(dP/ds)*(ds/2).Could you help me?

[@AviadorRPrado]

Watch the class 1/34.

[@imansalsa1654]

at 44.30, what is the R ? is it the radius of something ?

[@CPPMechEngTutorials]

It is the local radius of curvature of the streamline.

[@Meeroo670]

O G, very helpful

[@muhammadinamulhaq5786]

at 30:33 ,from where did dz come from?

[@CHERKE_JEMA5575]

That's the differential vector along the direction of the weight, and priorly we know it makes angle teta with the normal vector.

[@muhammadinamulhaq5786]

​@@CHERKE_JEMA5575 If you had replied earlier, this could have helped me pass my exam

[@ferhuda5336]

Why didn't you mention about rigid-body motion (Linear motion, rotation) at the end of the chapter 2?

[@phillipvo4561]

Yeah, can someone link us? I find that it is an important chapter.

[@shaneskinner5975]

@@phillipvo4561 kzbin.info/www/bejne/h2fWZKeNbpx_hKs The sound quality is poor, but the rest of his lectures are pretty good.

[@JohnDoe-qu4vl]

TRANSFER TO SLO!!!

[@matasemokal2057]

ب

[@roalba8947]

kind of boring explanation