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

[@rickandmorty2361]

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]

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.

[@aztatzirubioisaac8863]

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

[@lucastadesse2678]

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]

Thanks!

[@shadowknight385]

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

[@liregine7806]

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]

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

[@adityaali176]

$2k? rookie numbers

[@shuceybabdirahmanabdulle3324]

Pro help me the name of texbook

[@SAH-369]

Bro I wanna talk to u😮

[@d3inx251]

Really enjoyed, this is a great teacher. Thank you

[@CPPMechEngTutorials]

Thanks!

[@emmanueligbeka1222]

John Biddle you are a blessing!

[@alexandracarr8559]

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.

[@ronaldinho4eva1]

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

[@trololollolololololl]

Nice you are back, Love it

[@CPPMechEngTutorials]

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

[@joncastro5684]

Great professor, great lecture, thanks a lot!!

[@manuboker1]

Thanks ! Wonderful Heat Transfer lectures !

[@Quincy-Uryu]

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

[@kubrauysal2732]

Holman is great

[@YisraelFeranmi-ps9dh]

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

[@ahmedmokkedem7525]

Great professor, thanks a lot.

[@nageskumar5935]

Example for spherical instrument is wrong answer. Its 3.918 W

[@ghaithkafal-ghazal8332]

Surface area is 4*pi*r^2

[@sevgipnar5261]

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

[@HudaKids]

Thank you professor ❤

[@AlexJoneses]

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

[@joaopimenta7823]

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]

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

[@kslane1040]

Its the surface area of a sphere. Area of a circle would be (pi*D^2)/4

[@itzipocalyspe9396]

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]

I got 63.345 too

[@fdsman]

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.

[@korayerman4275]

I couldn't understand (be sure) about the area calculation of the sphere in radiation example

[@comedian2479]

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

[@EndTheATF]

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

[@germanarci8477]

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

[@toumiamal892]

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.

[@Bulayla1426]

Surface area of a pipe when you are neglecting the openings is just 2πrL 2r=D So you get πDL

[@jitenderyadav4993]

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

[@DurgaramProfDhawan]

Thanks Professor for kind teaching

[@ehsanhosainizadeh4847]

That was really helpful thanks

[@makinemuhendiss96]

Thanks for the lecture, it has a great explanations about the subject! However, i couldnt catch the point at the second example, why the equation divided by L? The air comes through outer sheel to inner shell center from side , so i think we should consider thickness as a radius of 30mm because heat transfer from outer side area to inner. If would air goes through from base of cylinder, we can think it as L, i guess. Does anyone thinking like that?

[@georgerobison5051]

I dig it. Good job!!

[@omarlee3095]

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

[@jazminwalls2591]

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?!

[@ernestb.2377]

I don't get the T_infinity term. Better call it T_surrounding?

[@Oxone_2KHSO5]

Amazing Man!

[@samra831]

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

[@jazminwalls2591]

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

[@Youtube.10a]

14:39 why no negative sign?

[@ikon9046]

My question too

[@mike-024]

Temperature hot minus temperature cold. Minus sign if doing reverse order. We simplified to delta T due to it being a 1 dimensional problem.

[@Mohammad62881]

Thank you for sharing this lecture

[@larrya.4647]

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

[@scott337]

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

[@shaahzweenyeldiablo9363]

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.

[@kdog2646]

The walls are of the large chamber. That's 77. For Ts you have to convert 40 C to Kelvin. That's the surface.

[@mainulhasan3113]

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

[@onlyAerik]

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.

[@eng.husam9]

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

[@GulzarAhmad-sw1kh]

Shouldn't q" be q in convection?

[@Iwasnt28]

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)

[@saeedesfandiar4698]

So good, thanks alot

[@GeoFry3]

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]

take your racism and GTFO

[@anshuraj9971]

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

[@onlyAerik]

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

[@سارهياسخضير]

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

[@Mkerlopies123]

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]

00.12.

[@devrajgoswami4357]

@@Mkerlopies123 thanks it helped

[@surajsinghkuldipsingh5383]

@@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.

[@reeboo1522]

​@@Mkerlopies123 thanks

[@abhijeetitare]

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

[@yiwang3437]

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.

[@eerie-000]

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]

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

[@scott337]

The person operating the camera is shockingly bad

[@samra831]

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

[@Mr1miko]

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

[@pedramjavadi2102]

Thank you professor

[@trololollolololololl]

Best proffesor

[@CPPMechEngTutorials]

We like him.

[@yoo_its_kg]

Wowowowow thank you

[@abhinandvarmaa]

wow

[@CPPMechEngTutorials]

I know, right?!?!

[@kamogelommankgeli3368]

the camera man was sleeping on this one

[@ownmohammad8618]

تحيه من الاردن

[@michael1567]

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

[@theazndonut1]

This camera man -.-

[@geektoys370]

Bro I cannot understand his handwriting