Sir i think you have missed the unit conversion from cm to meter and celsius to kelvin while substituting the values of temperature and radial distances @21:56... Since the thermal conductivity is in w/mK....
In thermal Resistance of an infinite Composite Slab we used t1-tw1 for first case while applying Newton law of cooling but according to the law it's Tw-tf so why we used t1-tw1 here ??
Generally , by MOLECULAR TRANSPORT EQUATION RATE = DRIVING FORCE / RESISTANCE for our case of heat flow from wall to fluid...(newton's law of cooling) is q = h A ( T of wall - T of fluid ) 《1》 Here, DRIVING FORCE = temperature difference RATE = q We want RESISTANCE to heat flow.... Then RESISTANCE = DRIVING FORCE / RATE.... by 《1》 1/ hA = temp diff / q Therefore, we get R = 1 /hA...
Sir I understood cylindrical heat conduction very well.. But the area is missing here in overall heat transfer coefficient.Anyone who can solve my doubt is welcome here
Good question, Because as soon as heat is conducted there is net transport of molecular kinetic energy along normal direction in a material from surface....So it is always normal to the isothermal planes so that temperature gradient forms to propagate it. It may be 2 or 3 dimensional depends upon the combined effect of thermal conductivity & temperature gradients. Though you apply the heat flux from any direction but at or from interface boundary it flows normally..... The fundamental law of transfer under potential gradient is always transport normally though the flux may or may not aligned with normal but as soon as it crosses the interface of the domain under study there is the flux normal to the interface...... Then be it - Darcy's law of - Fluid flow under pressure difference, Ohm's law of current flow under voltage difference, Fourier's law of this heat transfer under temperature gradient & Fick's law of mass flux transport under concentration gradient..... When there is transport flux across the interface, it always normally in or out of it.......
+Shyam Sunder formula you get is q= -k(T2-T1) x ((4* pi * r1r2)/(r2-r1)) you get this from the expression of fourier's heat flow of conduction q x integrating from r1 to r2(1/(4 pi r^2))= -k x integrating from T1 to T2(dT)
Yes. But following conditions - 1. Fluids are completely at rest & no relative motion exists either relative to any solid interface or within its own layers. 2. Convective heat transfer coefficient is very low & also radiation effects are such that they themselves are acting like non participating & solid to solid interface gap is very small. 3. They should have at least sufficient thermal conductivity for heat to pass or conduct through them. Their area of exposure should also be small. All these parameter should give overall trivial effect of some finite but very low thermal resistance. Otherwise, instead radiation will dominate.
![I.N "HALLUCINATION" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/n5B5q1Hwt_U/mqdefault.jpg)
This guy is so much easier to listen to than my heat transfer professor
i feel fulfilled in all categary of your lecture sir. My mind experienced that your lecture is a benchmark for HMT. thank you sir
There was a time when you used to get admission to MIT with just a recommendation letter from this guy
kya baat kr rhe ho bhai
@@prateekshivhare7245 doctorate overseas krne ke liye, college ke experienced professors ka recommendation letter lagta h.
He did his PhD from MIT in the year 1964.
@@tequilajoe518 does he still teach?
@@aryanraval110 he is just God Level
Watch at 1.25x speed...it's perfect
I did at 2x
thank you , you make it so easy.from algeria
Thankyou very much sir! The way the subject is taught here clears concept from basic like no other!
amazing! Dr. S! U the man!
We want better resolution like 480p and above for more picture clarity
that would be great
Bajoy kamshi donate a nice camera to the IITB
THANK YOU SO MUCH . that helped alot. ill be watching all of ur lecturs
thank you sir for making conduction derivations so easy
please give us content covered in the video into discription (i.e. name of the topics)
Great talent to express knowledge
Better if available in good quality 480 or 720p
watch at 1.5x speed
already watching at 2x :D
How did you put 1/Uri for overall heat transfer coefficient for hollow cylinder, it must be simply Uri isn't? Please tell me sir.. at 50:30
!thank you NPTEL and prof. S.P.Sukhatme
I own your lactures at least 2 university courses
keep up the good work!
Pure concepts... Thank you Sir.
Sir i think you have missed the unit conversion from cm to meter and celsius to kelvin while substituting the values of temperature and radial distances @21:56... Since the thermal conductivity is in w/mK....
THANKYOU VERY VERY VERY SO MUCH . to helped me alot ,and the great explanation . I will be watching all of your lecturs
In thermal Resistance of an infinite Composite Slab we used t1-tw1 for first case while applying Newton law of cooling but according to the law it's Tw-tf so why we used t1-tw1 here ??
Sir I would like to know how we arrived at the thermal resistance (1/hA) for heat flow from surface to fluid? From Newton's law of cooling.
Generally , by MOLECULAR TRANSPORT EQUATION
RATE = DRIVING FORCE / RESISTANCE
for our case of heat flow from wall to fluid...(newton's law of cooling) is
q = h A ( T of wall - T of fluid ) 《1》
Here,
DRIVING FORCE = temperature difference
RATE = q
We want RESISTANCE to heat flow....
Then RESISTANCE = DRIVING FORCE / RATE....
by 《1》
1/ hA = temp diff / q
Therefore, we get R = 1 /hA...
watching in 2021, better than online classes of any institution
thank u sir.. this video was very helpful
k = 0.58 W/mK here thermal conductivity is in K and T is taken in degree celsius?
thank you very much sir for simply undesting of conduction as easy as possible and plzz yarr improve quality of video 420p or more plzz..
Sir I understood cylindrical heat conduction very well.. But the area is missing here in overall heat transfer coefficient.Anyone who can solve my doubt is welcome here
thanks sir.. this video was very helpful my amie engineering
wow this is awesome, i may not attend lectures anymore...lol.
THANKYOU VERY VERY VERY SO MUCH but i want some value that is what is lenth of the hollow sphere 2 PI L K --------L?
wow.. u are great
sir anyone please help,,,if q is same every where then how we get two temperatures at two ends i.e, T1 and T2
How can I find that q in problem
Is there any length value
Is this in a playlist? I can't seem to find it :<
I was about to give you the link for the playlist, but then i checked the date of the comment its 7yrs old XD.
@@mro2038 😂😂😂😂😂ab tak to iski shadi bhi ho gyi hogi
@@SUPERMAN-ef8gh 2 3 bache bhi ho gye honge
now it's 8 years old comment.
@@SUPERMAN-ef8gh 😂
Thanks sir ,lecture is very good
Sir my question is why heat flows normal to the surface....
Because we are talking about temperature gradient in only one direction. Otherwise heat can flow in any direction.
Good question,
Because as soon as heat is conducted there is net transport of molecular kinetic energy along normal direction in a material from surface....So it is always normal to the isothermal planes so that temperature gradient forms to propagate it. It may be 2 or 3 dimensional depends upon the combined effect of thermal conductivity & temperature gradients.
Though you apply the heat flux from any direction but at or from interface boundary it flows normally.....
The fundamental law of transfer under potential gradient is always transport normally though the flux may or may not aligned with normal but as soon as it crosses the interface of the domain under study there is the flux normal to the interface......
Then be it -
Darcy's law of - Fluid flow under pressure difference, Ohm's law of current flow under voltage difference, Fourier's law of this heat transfer under temperature gradient & Fick's law of mass flux transport under concentration gradient.....
When there is transport flux across the interface, it always normally in or out of it.......
great explanation. thank you very much
THANKU SIR FOR YOUR LECTURES
nice lecture
thanks a lot
🙏🙏🙏🙏
very nice... thank you sir ...!!!
for hallow sphere whats the formula.and wher the l gone in dat formula
give me the answer sir
+Shyam Sunder
formula you get is q= -k(T2-T1) x ((4* pi * r1r2)/(r2-r1))
you get this from the expression of fourier's heat flow of conduction
q x integrating from r1 to r2(1/(4 pi r^2))= -k x integrating from T1 to T2(dT)
thanx buddy...
No problem. All the best for hmt
no audio what to do ?? please help me...
Suryakanth jadhav turn on your speaker
some lectures are not audible in my computer speaker but its ok on the smartphones.
very nice lecture
gr8 video sir
Great
Professor, I think you forget to convert the given temperature unit into Kelvin. Because, K (thermal conductivity ) is in Kelvin as per the question.
It's temperature difference, so not a problem
thank you sir
thanks sir...
Is conduction is possible in fluids.
Yes, Conduction is possible in Fluids in case that fluids are stationary such as hot water in a cup.
Yes. But following conditions -
1. Fluids are completely at rest & no relative motion exists either relative to any solid interface or within its own layers.
2. Convective heat transfer coefficient is very low & also radiation effects are such that they themselves are acting like non participating & solid to solid interface gap is very small.
3. They should have at least sufficient thermal conductivity for heat to pass or conduct through them. Their area of exposure should also be small. All these parameter should give overall trivial effect of some finite but very low thermal resistance. Otherwise, instead radiation will dominate.
Thnx sir
for sphere problem, Iam getting 437.3 w instead of 4.37 w .. can you help me anyone?
Convert Cm to Meters
thank u
can anyone tell the expression of Ur3
i want to know that too
@@ItsEshan392 just multiply the Right hand side by r3/r1. And you'll get it in terms of Ur3
I watch it on 2x speed cool
to good
Tooo tooo tooooo slow. I am bored. Please write fast or draw fast. Engg. students are able to grasp if the pase is fast.
How about you play it fast. Speed at x1.5 recommended., x2 if you can understand anything at this speed
i'm getting 8.75 instead of 4.35 @24:54
dia to radii
@@ameya2310 Thanks
@@shreyastaware jajajaja thanks XD
thank you sir
Problem1
he is skipping the derivation part, pretty bad Mr. Sukhatme :(
he teach too slow that make me boring
Increase the speed ..
bad intro
Thank you sir
Thank you sir 🙏