Fluid Mechanics: Fluid Kinematics (8 of 34)

0:01:07 - Eulerian and Langrangian description of fluid motion
0:07:59 - Streamlines, pathlines, and streaklines
0:13:30 - Example: Streamline equation
0:20:05 - Example: Streaklines, pathlines, and streamlines
0:36:56 - Acceleration and velocity fields
0:41:42 - Example: Acceleration and velocity fields
Want to see more mechanical engineering instructional videos? Visit the Cal Poly Pomona Mechanical Engineering Department's video library, ME Online (www.cpp.edu/meonline).
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)."

[@kamranshirazi3030]

I made a Python graph for visualization of this 4.11 example at time 19:43, I hope it helps: It shows the velocity vectors of the streamline with magnitudes and shows the vectors are tangent to the streamline. import numpy as np import matplotlib.pyplot as plt x = np.linspace(-1, 3, 19) y = np.exp(.5 * x**2 - x) - 1 u = x v = x * (x - 1) * (y + 1) plt.plot(x, y) plt.quiver(x, y, u, v) plt.show()

[@noahgeorge7305]

you've got a really good professor. He explains concepts really well :)

[@CPPMechEngTutorials]

We think so!

[@arunnarasimhan434]

here is a MATLAB code for those interested in the streamline example @ 19:16 x = 0:0.01:2; y = []; for i = 1:length(x) y(i) = exp(0.5*x(i)^2 - x(i)) - 1; end plot(x,y,"LineWidth",2); set(gca,"FontSize",18) box on,grid on; title("Streamline for example 4.11 Munson")

[@alperenkurt2892]

thank you for substituing all equations by yourself

[@abhijith3627]

how do we got stream line

[@nebacourage2130]

This video has been of huge help, thanks a lot.

[@CPPMechEngTutorials]

Hooray!

[@RahulKumar-bx7my]

what does local and convective acceleration signifies ?

[@cakefactoryy]

My FAVORITE PROFESSOR!!!👍

[@nebacourage2130]

Well done professor 👏.

[@SsSs-to4bb]

Sir, why do we plucg in 2 in the first velocity equation?

[@435iak]

We originally calculated the velocity at t=5 but need to include the velocity for when the steam last exits the smokestack where t=3. 5-3=2 so we have to plugin 2.

[@forrestercook8177]

this dude is a legend!

[@CPPMechEngTutorials]

Agreed.

[@franciscotejada1736]

why is the local negative

[@timotheecapot6308]

anyone know what textbook he is going off of?

[@adityaali176]

late, but for future references. fundamentals of fluid mechanics by munson et al.

[@MuhammadUsman-yv1yh]

why did we use du/dt for local acceleration instead of dv/dt? i know that in this case it would give the same answer but why have we don like that?

[@karenruby6781]

Muhammad Usman bc V is in the i direction meaning the x component & if we look at our a eqn, u would be x so dV/dt is specified as the local acc. Right? Well if we’re looking at v in terms of x and we’re using u as x it becomes du/dt

[@miguelrosario7314]

how did he find the local accel.?

[@cesar2259]

partial derivative with respect to t

[@anirbanbhattacharjee8620]

where we will get the problem sheets

[@CPPMechEngTutorials]

The problems in the video are from the course textbook. Munson, "Fundamental's of Fluid Mechanics", 7th edition.

[@adjourafik2669]

@@CPPMechEngTutorials send me a book please

[@syakirazmi5038]

Excuse me.At 28:11 It says 3 hours but he plotted on the graph as though he *2 the velocity equation. Why is this?

[@syakirazmi5038]

I think it has something to do with the last particle leaving but I cant seem to make sense of it

[@syakirazmi5038]

Oh I see. I just got it if you imagine the streakline moving from the origin to the 5 hr . Probably should have deleted my 1st comment than writing this but maybe someone could use it.

[@entropyx9229]

I still don’t get it. Can anyone explain?

[@tacteaches]

@@syakirazmi5038 Thanks . Your comment helped me understand this. :D

[@rahaswat3775]

@dijoe nice!

[@magnusbjrnseth9925]

What. A man!

[@theefficentpiggie8577]

44:10 why is the local acceleration negative?

[@A.Hisham86]

The derivate of 1/x is minus 1/x to the power square.

[@Moi_12344]

thanks

[@Campnou80]

Çaresiz derdimin sebebi belli dermanı yaramda arama doktor.

[@yigitcanmujdeci8165]

puhahahahaha

[@cengizhanermet]

Hahahahahah

[@kaanuysal5402]

ASLDKJFHSADJLŞFHAFDLJŞ

[@sagarku5533]

How to join this university

[@CPPMechEngTutorials]

www.cpp.edu/admissions/index.shtml

[@bhradramazani]

For streakline at 10 hours, why do we not use 7 hours since at t=10 hours, it has been 7 hours since the last particle left? So if we weren't asked to find the streakline for t=5 hours but only for t=10 hours, then our x and y values would instead be (70,-35). Dr. Biddle's graph for t=10 hours is (75,-25) by accounting the 2 hour difference from t=5 then multiplying 5i by 5. Why isn't the second point accounted for like t=5 hours after the shift?

[@aaliyahomar7126]

Hi. I think that since the streakline for t=5hrs took the 2hour difference into account all we have to do from t=5 to t=10 is shift it by the velocity v=5i. Since the slope of the line is already taking the 3hour difference of the first and last particle into account. Hope that made sense

[@niyomugabofabien6881]

thanks for explication,but we need assignment sheet

[@turkergoktas777]

Fundamental's of Fluid Mechanics", 7th edition

[@adjourafik2669]

@@turkergoktas777 send me a book please

[@turkergoktas777]

@@adjourafik2669 i don't have electronic book sorry

[@adjourafik2669]

+türker göktaş thanks man

[@dremr2038]

33:00

[@MD-rd8vt]

ridiculous audio at the beginning. fix it.

[@eliftengilimoglu9418]

Oh well everyone talked about a nice explanation but wait I dont hear any ? A whole video he barely talks more reads and the quality of sound is really bad. It could be more open

[@emrahonen9279]

Eğer güzel bir sayfa bulursan veya bulduysan cevaplar mısın yorumu

[@muhammadinamulhaq5786]

know anyone who does that?