Heat Transfer (02): Introductory examples, energy balance on a control volume and control surface

Рет қаралды 116,163

Күн бұрын

Note: At 0:38:12, the answer should be 3.92 W
0:00:15 - Review of previous lecture
0:06:29 - Heat transfer concepts applied to a cup of coffee
0:11:22 - Example problem: Conduction
0:22:47 - Example problem: Convection
0:32:06 - Example problem: Radiation
0:38:19 - Energy balance equation on a control volume & control surface
Note: This Heat Transfer lecture series (recorded in Spring 2020) will eventually replace the earlier Heat Transfer series (recorded in Fall 2015) in a couple years. The old lecture series had some errors and was lower quality.
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 Spring 2020. The textbook is "Fundamentals of Heat and Mass Transfer", Bergman et al., 8th Edition.

Пікірлер: 82

@rickandmorty2361 2 жыл бұрын

Sir you should keep uploading these videos , you're doing a great service to the students who are stuck in this pandemic. Even if there is one person seeing your video you should go on ,given that you're so good at teaching atleast future generations will value it. So far you're underrated. Thanks!

@ryancowles5633 Жыл бұрын

Not heat transfer related but you sir helped me graduate with my civil engineering degree when I was struggling with my fluid mechanics course. Most of my professors were in it for research, not teaching. You are one of the few that actually care about what their students learn. From the bottom of my heart, THANK YOU.

@lucastadesse2678 5 ай бұрын

I have attended all of my heat transfer lectures but I am still struggling. However, watching these online has really helped my understanding of what's going on in class thank you! You are truly a great teacher!

@CPPMechEngTutorials 5 ай бұрын

Thanks!

@liregine7806 3 ай бұрын

I am loving this youtube channel. It would be so great to have you when i was studying, your students are so blessed!

@Steve.Nguyen 3 жыл бұрын

He lectures better than my Professor who costs me $2k+ 😫

@adityaali176 2 жыл бұрын

$2k? rookie numbers

@shuceybabdirahmanabdulle3324 Жыл бұрын

Pro help me the name of texbook

@SAH-369 7 ай бұрын

Bro I wanna talk to u😮

@shadowknight385 7 ай бұрын

I literally have an exam this afternoon, and here I was totally blank about the subject, after watching 2 videos I can say I understand the basics and will continue to watch these and will try to score decent in the exam. thanks a lot sir for such wonderful lessons

@alexandracarr8559 2 жыл бұрын

When you do the calculations for the second example, the answer should be 63.3 W/m^2*K. Not 65 because he changed the 0.035 to 0.030 which is given in the problem.

@aztatzirubioisaac8863 8 ай бұрын

The mix between science and comedy always give the best lectures. Tnks a lot.

@emmanueligbeka1222 3 жыл бұрын

John Biddle you are a blessing!

@joncastro5684 2 жыл бұрын

Great professor, great lecture, thanks a lot!!

@manuboker1 Жыл бұрын

Thanks ! Wonderful Heat Transfer lectures !

@d3inx251 2 жыл бұрын

Really enjoyed, this is a great teacher. Thank you

@CPPMechEngTutorials Жыл бұрын

Thanks!

@ronaldinho4eva1 3 жыл бұрын

Dr. Biddle be double cuppin'. I see the hustle.

@georgerobison5051 2 жыл бұрын

I dig it. Good job!!

@ahmedmokkedem7525 10 ай бұрын

Great professor, thanks a lot.

@Mohammad62881 2 жыл бұрын

Thank you for sharing this lecture

@DurgaramProfDhawan Жыл бұрын

Thanks Professor for kind teaching

@trololollolololololl 3 жыл бұрын

Nice you are back, Love it

@CPPMechEngTutorials 3 жыл бұрын

The pandemic slowed us down a bit. We have some new videos that will be pushed out in the next few months.

@samra831 2 жыл бұрын

Thank you for the video...super help!!!

@YisraelFeranmi-ps9dh 4 ай бұрын

You really helped me so much sir Hope to keep seeing your videos

@ajax3375 5 ай бұрын

Dear Professor, can you please refer me what standard books for Heat Transfer I must follow. And thanks a lot for your wonderful lectures!!

@AlexJoneses 2 жыл бұрын

honestly why can't heat just stay where it is, would make my life right now a whole lot easier

@AV-DIN 3 жыл бұрын

Amazing Man!

@pedramjavadi2102 2 жыл бұрын

Thank you professor

@saeedesfandiar4698 2 жыл бұрын

So good, thanks alot

@jitenderyadav4993 2 жыл бұрын

Sir can you please tell the name of book 📕which you refer?

@omarlee3095 2 жыл бұрын

wouldnt there be conduction as well in the second problem? If not y ?

@yoo_its_kg 2 жыл бұрын

Wowowowow thank you

@eng.husam9 Жыл бұрын

Where can I find the papers explained by the doctor???

@larrya.4647 2 жыл бұрын

if only the camera man was half as good as the professor -_-

@scott337 2 жыл бұрын

The camera man from Fluids was great. This person seems lazy

@jazminwalls2591 2 жыл бұрын

Hello sir, my name is Jazmin I am majoring in chemical engineering but attending class for heat transfer is not beneficial because he simply reads from slides. I can not thank you enough for your videos. If it were not for you, I would be failing the class. DO you teach MASS TRANSFER AS WELL?!

@jazminwalls2591 2 жыл бұрын

DOES ANYONE KNOW OF ANY GREAT VIDEOS I CAN USE FOR MASS TRANSFER?!

@sevgipnar5261 4 ай бұрын

In 28:55 what is q prime formula? the cameraman didnt show that part. It's written on the right side of the board.

@shaahzweenyeldiablo9363 4 ай бұрын

at 37:4 the question regarding radiation, why it isn't Tsurr = 40C ? since the walls are 77K. Can someone please explain to me in detail.

@rhed321 Жыл бұрын

For the cubical freezer problem the degree C and K is not driving me crazy but what is driving me crazy is the area.Is it the area of the inner side of the insulation or the outer side of the insulation?

@fs17learner 11 ай бұрын

Yeah, actually it was to be left with 2x2 only. The outer area.

@itzipocalyspe9396 3 жыл бұрын

I believe the answer to the convection problem is wrong. With the values Dr.Biddle used I was getting h=63.34 (W/m^2K) @30:40

@dinnaruto 2 жыл бұрын

I got 63.345 too

@fdsman Жыл бұрын

Yes he put in the value 0.100 for the diameter instead of 0.03m, what he wrote should give you 19.003 but that's not what he put down.

@comedian2479 2 жыл бұрын

this is a mad man, no 273 for c and k

@EndTheATF 2 жыл бұрын

proportionally, C and K are equals. It wont make a difference in the calculations.

@joaopimenta7823 Жыл бұрын

Just to point out that in the power dissipated part at 36:40 he uses de diameter to calculate the area of a circle with the incorrect formula.

@rebekahbonne8688 Жыл бұрын

it's not the area of the circle but the cylinder's curved side (2pi*r)*L or as he wrote, pi*D*L. This is "a very long" cylinder so I assume we do not consider the two circles on each side of the cylinder, only the curved surface

@nageskumar5935 2 ай бұрын

Example for spherical instrument is wrong answer. Its 3.918 W

@abhijeetitare 3 жыл бұрын

ref to radiation problem: why Tsurr=77K and Tsurf=40C, i can also take reverse of that?

@yiwang3437 3 жыл бұрын

Because it simulates the out space, it has a physical meaning. If u have a really cold Box positioned in a warm room, yes u can reverse them.

@GeoFry3 Жыл бұрын

Wish I had found this when I went through heat xfer. My instructor was more about getting awards (affirmative action hire) and his bow ties. Not much on actually teaching.

@onlyAerik 6 ай бұрын

take your racism and GTFO

@scott337 2 жыл бұрын

The person operating the camera is shockingly bad

@trololollolololololl 3 жыл бұрын

Best proffesor

@CPPMechEngTutorials 3 жыл бұрын

We like him.

@ownmohammad8618 Жыл бұрын

تحيه من الاردن

@abhinandvarmaa Жыл бұрын

wow

@CPPMechEngTutorials Жыл бұрын

I know, right?!?!

@mainulhasan3113 6 ай бұрын

can anyone tell me what is the book name sir is following?

@onlyAerik 6 ай бұрын

read the video description. "Fundamentals of Heat and Mass Transfer", Bergman et al., 8th Edition. my heat transfer class starts in 2 days. we will be using "Fundamentals of Heat Transfer", Kreith et al, 8th Edition. Biddle's first video and our textbook sections 1.1 to 1.5 are pretty identical.

@germanarci8477 4 ай бұрын

28:30 can someone expain why the area of the cylinder is pi*D*L ?

@toumiamal892 21 күн бұрын

hello i think it's not the whole area of the cylinder, it's the area of the outside of the cylinder (the one with contact with the air). We take the perimeter of the cylinder and we multiplie it by the length. think of it us the area of the shell of the cylinder without the two bases because that's the only surface that is perpendicular to the air direction.

@anshuraj9971 Жыл бұрын

Area of cube is equal to 6a^2 ??

@onlyAerik 6 ай бұрын

Yeah. Surface area. 6 sides, each side has area a^2

@Youtube.10a Жыл бұрын

14:39 why no negative sign?

@ikon9046 Жыл бұрын

My question too

@samra831 2 жыл бұрын

Question on Radiation prob: Area is the area of sphere or circle? is 100mm a diameter or radius? Thank you

@Mr1miko 2 жыл бұрын

It’s a sphere diameter formula for area: S(sphere)= pD^2

@GulzarAhmad-sw1kh 8 ай бұрын

Shouldn't q" be q in convection?

@Iwasnt28 8 ай бұрын

q = q”A they’re not the same regardless of the mode of transfer so in convection q”=h(Ts-Tsurr) while q= qA(Ts-Tsurr)

@kamogelommankgeli3368 Жыл бұрын

the camera man was sleeping on this one

@theazndonut1 2 жыл бұрын

This camera man -.-

@michael1567 2 жыл бұрын

anyone know what the requirements for sainthood are? I'm pretty sure you meet them professor

@user-kv8cn1gf9s 3 жыл бұрын

I cant understand how it became 5*2*2 in 00:16:16

@Mkerlopies123 3 жыл бұрын

5 is the sides of the cube (it's not six because the bottom side is perfectly insulated, so there is no heat transfer over that side). 2*2 is the area of the square. So it's a total area of that freezer

@Abiola426 3 жыл бұрын

00.12.

@devrajgoswami4357 2 жыл бұрын

@@Mkerlopies123 thanks it helped

@surajsinghkuldipsingh5383 Жыл бұрын

@@Mkerlopies123 But the question is about thickness of insulation, so i think we need to just consider one side of insulation which would mean 2*2 only. doesn't 5 make it wrong? enlighten me if i misinterpreted.