Fluid Mechanics: Pascal’s Law, Hydrostatic Pressure Variations, Manometry (2 of 34)
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- Опубліковано 22 сер 2024
- 0:00:10 - Reminders about density and viscosity
0:01:48 - Pressure at a point in a static fluid (Pascal's law)
0:08:29 - Pressure distribution in a static fluid
0:23:45 - Example: Pressure distribution in static fluids
0:31:29 - Unit conversions for pressure
0:34:23 - Example: Pressure distribution in static fluids (continued from earlier)
0:35:45 - Pressure measurement (manometers)
0:48:24 - Example: U-tube manometer
Want to see more mechanical engineering instructional videos? Visit the Cal Poly Pomona Mechanical Engineering Department's video library, ME Online: www.cpp.edu/meo...
This lecture series was recorded live at Cal Poly Pomona during Fall 2014. The textbook is Munson et al., "Fundamentals of Fluid Mechanics (7th edition)."
Give me some details about the book he uses during this course ?
Munson, "Fundamentals of Fluid Mechanics", 7th edition.
Thank you so much. I paid several thousands of dollars for this class and this videos are way more helpful than the lectures at my university. Please post more courses.
There are a few more in the pipeline, but it takes a while to produce them.
i have my final exam on Tuesday and now i found these videos.I am regretting of not finding it before :(
good that in EU we got unis for free, i would sue uni if I had paid for such a bad teaching
I go to UIC. Every single fucking fluids instructor is a dumpster fire. I complained to the dean, and now I need to watch these videos to even have an iota of what is going on. I literally watch these before lecture. 1/34 down, 33 to go.
Students at UTA are thanking you Professor! I've learned more about chapters 1 and 2 in the past 2 hours than I have for months in my lectures. Thank you!
I studied this chapter so many times by reading the notes, understanding the class, understanding the book but it only took a class of 1 hr of his lecture to clear the whole concept. I genuinely admire him. Wish he was my professor, I would have loved to attend all of his classes.
This guy is an amazing teacher. I like how he ends with problems to connect the theory. Great work
I'm so glad I found these videos!!! Very helpful and clear, thank you very much Prof. Biddle for making my life a lot easier
That is what he does. :)
Dr. Biddle I thoroughly enjoy listening to your lectures. I am very calm when you explain
You are the best fluid mechanics lecturer ever !!! Full of thankfulness from METU, Turkey.
get aq
ua-cam.com/video/Mqkl1mCS2_8/v-deo.html
Love the enthusiasm and how succinct the presentation is. Wished I went to CPP.
It's never too late to apply. :)
Thank u professor, this is actually helping me get an idea of the topics before going in class.
Your effort and determination into making these videos is much appreciated.!
You're welcome!
im really saying this from the bottom of my heart thank you for making this vedio. my professor stands no chance in teaching while comparing professor biddle
These videos are lifesavers! Thankyou so much for uploading them
You're welcome!
Thank you so much... You have been my saviour.. Wish I have found this before, I just found out today and I have exams tomorrow.. When comparing what you teach to what my professor taught, he hasn't taught anything.. I should have found your lectured before.., 😕😕 anyway thank you so much.. You saving so many lives of students.. 💜 💜
Thank you from the UK , I don’t even know why i am learning this, i want to major in biology and dropped physics/ engineering in year 11.
Tanks a lot. You're helping a guy from Brazil.
Hooray!
Thanks from Rio de Janeiro, Brazil!!!
Thank you for the wonderful content, your enthusiasm and professionalism is untouched!
well-explained... thank you sir for sharing :)
-regards from Philippines
You're welcome :)
wow thank you so much, this saved me a lot of time and now i have the knowledge i needed!!
So glad this is available during quarantine lol
THANK YOUUUUU SO MUCH SIRRRRR!! VERY VERYYYY DETAILED LECTURE!!
Yoooouuuu are weeeeelcoooooome. :)
That absolute genius at 19:01 going "Just breathe on it".
Thank you, well explained.
i'm not a uni student (starting uni next year), but this is really helpful for understanding different processes because in school they can only explain them to a certain point (like, no proof for pascal's law, just "oh yeah the pressures are the same")
however, there are some things that are really confusing for me because i'm not from the US, a lot of our units and letter symbols (e.g. we use S instead of A for area and A instead of W for work) are different... thanks anyway!!
Grateful for all the uploads. Any chance you can bless us with practice exams?
Not at the moment. Perhaps when Professor Biddle finally stops teaching we can make them available.
Great lecture. But sound clarity is not good. Baground noise is coming.
can you explain the step beginning at 57:30, ending at 1:02:31. Where does the gamma(water) come from that gets multiplied to [SG(water)+SG(gage fluid)]
Since we neglect air, we are left with SG(water) + SG(gage fluid). Recall that Specific Gravity is the ratio of the density of a substance to the density of a water. That is Specific Gravity, SG = {density of any fluid} / {density of water}
Since we need density of gage fluid, and know the SG(gage fluid), we can multiply it with density of water to obtain the density of gage fluid.
Pa = [ SG(water)*density(water) ] + [ SG(gage fluid)* density(water)]
Pa = [ 1 + 3 ] * 62.4
Pa = 250 psfg.
I hope that answer your question, of anyone in the future :)
@@runtime_engineer
OK thank you
But
Why he said that P(atm)=0.
We know that the pressure atmosphere =1atm
@@Abedalrahman-Edris Because that's the gage pressure. A gage not connected to a system with pressure reads 0 because it neglects the atmospheric pressure. (Think about reading a tire pressure gage). If we were talking about absolute pressure, Psia, then we would have used the true atmospheric pressure. I know this comment is from a year ago but I hope that helps.
Great lecturer, Dr. Biddle - one born to teach!
The hydrostatics (not limited to this lecture) misses one point: gases are compressible and liquids are not. This essential difference is missed since liquids and gases are treated as if they acted the same. This results in strange principles, for example, that like a gas, the pressure exerted by a liquid against the walls of its container are the same as the hydrostatic pressure, which completely bypasses the issue (not existent in gases) of mass, resulting in a liquid in the case of narrowing container towards the top, of exerting more force against the base than its weight! How a liquid possibly exert more force than its mass against the base than its weight?
Thank you, Dr.John Biddle
from the Islamic University of Medinah✌🏻✌🏻
Professor at 44:39, I will call the point where the h1 ends as Point A, and to the point which is horizontal to point A as Point B.
Now as you said: Pressure at Point A = Pressure at Point B.
Point A is equal to = Pcenterline + h1gamma1
Why the pressure at Point B is not equal to Patm + h2gamma2 ?
So much respect for you professor
Awesome lecture, thank you!
You're welcome!
Videos and explanations are really great! I wish would specify the unit equivalents according to the SI system :((
Thanks dr. Love from Malaysia❤😆
this guy is good
파스칼의 법칙을 처음배우는 것은 바로 중학교 때입니다. 사실은 중학교 때 배우는 내용이라 큰 의미가 없을 줄 알았는데 역학의 전반을 차지하는 중요한 법칙이었다는 사실을 이 영상을 통해 깨달았습니다. 감사합니다.
very well explained!
thanks for such a beautiful video
Thanks for the compliment.
Thank you so much ! from Algeria
You're welcome! From Pomona.
A bit confused in the calculation due to non-SI measure units. Yet I can comprehend the general concepts. Overall, this is a great lecture. Thanks.
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Hello, this is very helpful, thank you for sharing. At 11:26 you're expanding pressure like the taylor series, why is that?
Dunno if you still need answer but taylor series expansion is a series expansion of a function about a point it doesnt matter dy/2 or dy/3 you can found the pressure function about dy/3 or dy/4 etc.
All throughout engineering, whenever we examine small elements we often make a linear approximation to the Taylor series by truncating all terms with dx^2 and higher. For small fluid elements, dx is small. So dx^2, dx^3, etc... are very small and those terms can be neglected.
Would it be possible to acquire the list of problems which Dr.Biddle assigns for homeworks?
How can I thank you? It is so clear,so interesting to understand what is behind these formulas. In my university in Italy we use in our course the same book Munson. But my professor didn't succeed in explaning these things, which are a little complex, like dr. Biddle does.
Can I make a small contribution with my credit card to fund this amazing website?
Sorry for my poor English.
We appreciate your support, but no need to make a donation.
Your English is fine. :)
why dP/dy times dy/2?
I cant understand how you are getting the expressions on the four sides of the element at 9:51
Can someone please explain? Thanks. And also why it is negative vs positive?
Negativeand positive are with respect to P at the centre
Do u know what the significance of the expression (dp/dy) and (dp/dz) is?
Excellent!
Agreed!
How did GammaW + GammaGF turn into (SGw+SGgf)*GammaW at the end.
divide whole equation by γ(water)....And then move γ(water) from denominator of Pa to R.H.S of equation.
thanks professor!!!!!!
ua-cam.com/video/Mqkl1mCS2_8/v-deo.html
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You are a genius sir
Very nice compliment. :)
I don't understand why the professor assumes Patm= 0 in the manometer equation. Is this absolute P? meaning that the answer would be an absolute P too..?
at around 22:00 When you were cancelling out the dydz_s shouldn't they arithmetically sum up to -3dydz?
58:11 (4 DEGREE, not 40)
Thanks alot.....
hey I just wonder at 44.28 why are we neglecting the atmospheric pressure
5:25 why isn't he taking the component of P in the y direction in the second part of equatyion
I love You Professor!!!
:D
You are just amazing :)
Yes he is!
fatima ezzahra hilal
you too
Awwww
Can i take thos course online through global education? I cant learn from the fresno state professor
how did gamma water + gamma gage fluid equal to (SG water + SG gf)*gamma water?
also, 62.4 is the density of water right?
What is Pressure in x-direction in Pascal law? why only P_z , P_y and P_s and why not P_x?
At 31:15 could you explain why Pa=Pb? Since it's the same liquid in both the containers and the free surfaces are at different levels, shouldn't be pressure be different? The weight of liquid above "a" is larger than that above "b". Does that not play any role in determining the pressure?
go to 48:00, the thing is that in Pb the air makes a tiny pressure thus comparing to a liquid is negligible but following the rule to "same level and liquid" the Pa=Pb
He states at 4:16 that the area that the force acts on is the left side and is delta z times 1. Why is it times 1?
He assumed that the depth is 1
could someone elaborate how the gamma of guage fluid turned into SG of guage fluid multiplied by gamma of water?
Happy teachers day 😍🥰🌹❤️ ...
ua-cam.com/video/Mqkl1mCS2_8/v-deo.html
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I have questions for when he's explaining pressure being equal at 34:45. Wouldn't the pressure be different at different heights even if the it is the same liquid and continuous ?
If you have two locations at the same elevation, and the two locations are in a continuous fluid (there is no barrier completely blocking the two points), the pressure will be same at those two locations. As you move up and down in the continuous fluid, the pressure will decrease and increase, respectively.
what is dp/dy?
Sir 57:33 onward didn't understand how you wrote the terms ... Please explain ... Water fluid +air fluid +gage fluid ... I couldn't understand how you did after ...
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👍🏼
Are those videos for civil engineering students or mechanical engineering students?
When this lecture series was recorded, both CE and ME students were in the course.
great resource! But may I ask what happened to the closed captioning?
+Josh Pham This will be taken care of by January. We are in the process of revising the fluid mechanics lecture series.
nice
what is the unit of 62.4? is it lb/ft^3??
Yup. lbf per ft^3.
why we took p+ or p- at 11.17. bcz we want to find pressure difference?
Can you provide a time stamp?
@@CPPMechEngTutorials The text was in the wrong format. 11:17
Can I get the book your use here please
at time frame 10:40 why is pressure pointing right negative?
The pressure force (pressure * area) is negative on the right side because it always points inward. However, pressure is a scalar and always positive. Since we are examining a 2D object the "area" is just dz on the left and right side. If the object is 3D and the length into the board is dx, then the area would be dxdz.
6:09 Delta S is equal to Delta S times sin of theta?
the horizontal scalar component of P perpendicular to the hypothenuse is P * sin(theta). Since he's talking about summing the forces (not the pressure) we need to use F = P * A.
The first line should be Py*(Δz)(1) - P*(ΔS*sin(Θ))(1) or in words the horizontal force from Py minus the opposite force from P. The horizontal component of the area is ΔS*sin(Θ) because you're splitting a vector into components by using the sine and cosine relations from trigonometry. This NASA page has a nice explanation of that: www.grc.nasa.gov/WWW/K-12/airplane/vectpart.html
We do that horizontal component *(1) of the length into the board direction for the area and then *(P) for the resulting force in the horizontal direction right to left that cancels out the force of Py from left to right. Leaving the sin(Θ) out at first is a mistake. I hope that makes sense lol :)
@@tycho_m thanks
Which book is this ?
Poor quality of voice
Proff is great
can someone explain how he went from gamma(w) + gamma(GF) to (SGw + SGgf)*gamma(w) ?
I read both of the comments but cant understand, can someone break this down?
Logan The formula for specific gravity is: SG = gamma(fluid in question) / gamma(water), so he replaced the gamma of each of the fluids with SG, then multiplied by the denominator in the SG formula; aka, it’s a bit of substitution! [ gamma(GF)=SG(GF)*gamma(water) ] I think it makes it a little bit easier because you don’t have to do any extra math to figure out gamma(GF); you just have to remember gamma(water) there.
Nicholle Willis thank you the reply. Tbh I’m not sure if I ended up understanding this or not lmao. But I passed fluids with a B+ so I guess it worked lol. This prof is the bomb. Thanks for the reply tho! Good luck with your fluids class
I have been working on snowmobile "spin surfing". I have worked a formula and a concept to climb out of deep water. I would like to share and discuss.
Iguana
Why dy/2 and dz/2 why.....???
Since center of the rectangle is the reference, either side you travel equals a distance of dy/2 or dz/2. Observe that each side has length dz and dy
am i right i heard that the temp over here is 76.4??
can i get the subtitle of these videos ?
Unfortunately no. It would be too time consuming if we fulfilled everyone's requests for a copy of the subtitles.
Professor is awesome but the camera guy could use a cup of coffee
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can u provide the name of book which he is referring to
Munson, "Fundamentals of Fluid Mechanics", 7th edition
👍👍✋✋