Heat Transfer: Crash Course Engineering #14
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- čas přidán 22. 08. 2018
- Today we’re talking about heat transfer and the different mechanisms behind it. We’ll explore conduction, the thermal conductivity of materials, convection, boundary layers, and radiation.
Crash Course Engineering is produced in association with PBS Digital Studios: • All PBS Digital Studio...
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RESOURCES:
www.grc.nasa.gov/www/k-12/air...
hyperphysics.phy-astr.gsu.edu/...
coolcosmos.ipac.caltech.edu/co...
hyperphysics.phy-astr.gsu.edu/...
spaceplace.nasa.gov/beat-the-...
www.weather.gov/jetstream/heat
physics.info/conduction/
physics.info/convection/
physics.info/radiation/
thermopedia.com/content/781/
Çengel, Yunus A., and Michael A. Boles. Thermodynamics: An Engineering Approach. 8th ed., McGraw-Hill Education.
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WHERE WERE YOU WHEN I TOOK HEAT & MASS TRANSFER?!?
instead of reviewing my class notes i am gonna use this to pass my job interview.
i got the job btw, and this helped
@@1mijaz niiiice
1mijaz good job bro
1mijaz what job interview did you get 😂😂😂
@@gamezonedaily_ Project Engineer at a heat exchanger manufacture
i actually live in cambodia and this is how i do it: two open windows with mosquito net and a fan blowing air between them. reverse according to which side of the house receives sun. im directly under flat roof which gets super hot from full sunlight so hot that just the radiant heat makes my desk hot while the air is not. and this is the only thing that keeps the room comfortable. the roof receives about 700 megajoules per day. when the heat is the worst i dump water buckets on the roof which evaporate quickly. one bucket reduces this by 40 megajoules. so 18 buckets eliminate the sunlight completely. a rack with wet clothes inside the room also helps obviously.
Thank you for the nice, interesting pictures. I find that learning hard things is SO much more pleasant and less stressful (and so I learn better) when it's in bright, lively colour.
This subject adapted to the kitchen is so needed: there a lot of cooks who don't seem to understand the basics of heat transfer, for example a veggie pizza with all the veggies dumped in the center results in a puddle of water in the center, and all the toppings sliding off. The veggies need to be spread out to the edges. The same goes for the sauce, it does no good to just slap the sauce on carelessly and have the edges burning up and the center soggy.
The Metal Gear Solid reference made my day!
Once again, back to physics and thank goodness I am refreshing this
Thank you for this engineering series please expand I need more videos before I graduate haha
This is a great review for architecture students, especially with the examples used
Heat conduction is a major hassle for thermoelectric coolers. The idea is pretty interesting, a cooler without moving parts, just pass an electric current through and it transfers heat from one face to the other (you can even reverse it by inverting the current). The problem is that you need a material with good electrical conductivity, otherwise it's going to generate a lot of heat due to the Joule effect. But good electrical conductivity generally implies good heat conductivity, so the material transfers heat back from the hot face to the cold face, like trying to fill a bucket with a sieve. That's why thermoelectric coolers are much less efficient than compressor-based coolers, although researchers keep finding better materials to improve performance little by little.
So you want something with good electrical conductivity, but bad heat conductivity? Umm...water? Not distilled, of course.
@@ArawnOfAnnwn well isn't water quite good at heat conduction. For example try grabbing a hot oven plate with a wet glove on, you'll burn yourself a lot more then, if it was dry
I didn’t read anything
Plate heat exchangers are almost unbelievably efficient. A small one maybe 20x10x5 cm can easily heat up water from 10 c to 30 c at incredibly high flow rates. It can essentially ensure that a house will never run out of hotwater because it can produce it so quickly that you can get hot water for every appliance and the shower in a home. Having lived my entire life with one I was stunned at the concept of running out of hot water when I heard about it.
Nice rapid pace to this video, thank you!
Question, if I have a fixed heat source downstairs in an extension, how can I best cause the heat to move upstairs?
oh my God I died a little when I saw Solid Snake moving inside the box
*I hear tell of quadruple-pane windows with special coatings that reflect the infrared and ultraviolet parts of the spectrum so that the only radiation that makes it inside your house is useful, visible light.*
*Use solar panels to catch everything that would otherwise be hitting your roof.*
wow what an excellent video amazing!
Liked the MGS reference at 1:42.
Thank you for breaking it down for us. We have an RV and we are trying to help the small air conditioner during the summer. We cannot put more insulation on the inside but we can put something to block the direct sunlight from contacting the top of the RV
Can you guys at crash course do a geology course? Love your videos so much by the way they are so fun and educational
PBS always Admires me !
Please do a video on aeronautical engineering... I really love aeronautical engineering and I really want to become an aeronautical engineer in future.
well done!
Could you please talk about SSD (somatic symptom disorder)?
0:50 I freaked out because I was watching at night and I thought someone screamed
GLaDOS lol
lol omg
Same
lmao
Omygosh lolll
The most awesome CZcams series out.
Ayy I see you throwin’ shade at h3h3 at 4:28
Saw that too! We gotta get ethan to see this
People wear beanies too lol
Saul Goodman shut up
I remember this was the first thing I learned when learning hvac
Hi dear... Your videos are so much useful for me and others..... Please keep uploading videos....... Thanks a lot...... Hats off to you a your team.... God bless you dear ✨✨✨✨
In medical physiology we study same principles, difference is how our body solves the problem, but even then the mechanisms are same.
*_...please, simplify this for physicists:-heat transfer is by photons exchanged by atomic orbital electrons, certain materiels might have slower or even 'uphill' heat flow, directed magnetically, or by reflection on smooth inner surfaces, or, per your title, transferred by Fermi-level-conduction-band electrons and-wait for it-not mongols, but-'free holes'... (which'd be 'solid' convection, except, it's at bulk-temperature, so-what, type, is, that)... ((and then there's Mach-Principle groundstate-minimum-oscillatory-energy 'sharing'))..._*
i understood some of those words... ^^
So convection is a special type of conduction?
The shelf is giving me anxiety. Lasted 2 minutes. That’s good enough right?
I love cc but i rlly would like to know about ocd because i have it ;(
I am an architect in a beautiful tropical country of indonesia . Found this very helpfull, although I've hear it from highschool but it's just go by cz there is no case to solve
4:12 transfer*
I'm so good at this
dan iel transfer*
tranz ferdinand
dan iel transfer***
LGBTransfer
dan iel transfer****
Please do Aeronautical Engineering
You can work and research Heat Transfer following the career of Chemical or Mechanical Engineering.
So to battle the radiant heat put an reflective aluminum barrier on top of your existing insulation put a solar fan on your roof ( because we’re trying to save energy) to force ventilate and pull the heat out in the summer . Now insulation has a saturation point just like a sponge can only resist or absorb so much water , insulation can only resist or absorb so much heat before it becomes ineffective the saturation level is usually around 125degrees f so it seem that if I can add a reflective barrier on top of my insulation it would keep my insulation protected from radiant heat and my insulation would not reach its saturation point hmmmmm I feel a science experiment in my near future!
My teacher made me watch this
METAL GEAR????? 1:44
Amazing Fantastic Spectacular Explanation Ma'am! PROUD OF YOU!
Radiation has more to do with the heating than conduction itself. If you create a radiant barrier, you will minimize the heating of the walls, and then will not need thick layers of other insulations, or walls for that purpose. If you read about MLI from NASA you will see that radiation is the main focus on space, as it should be on Earth, since the heat source is the same. (the sun).
Im talking about how it impacts buildings, as it is on the video, real life situations.
Is that Wall-e on the shelf?
yes
Thanks for being ho- helpful with this tutorial🥵
What is heat radiation and is it like electromagnetic radiation? Heat can transfer in vacuum also but how? When anything is heated then its molecules vibrate rapidly but why anything that comes near that object also heats up? Is it something like electromagnetic radiation?
1:47 Doctor Zodberg image 😃
zoidberg* and ok?
In between glass, vacuum or less heat conductant gass than oxygen..
can i have the anchor contact no ??
2:46 what about the roof ? does taller building make the heat transfer lesser?
When one is near a fire. Is it convection that makes the air around hot or radiation? Probably both but which is more responsible?
Radiation
Smoke and hot gasses from combustion rise due to thermal convection heating the air along with them. If you were to feel the actual hot air from the fire you'd know it very quickly lol. When sitting around it normally all you're feeling is radiation, which doesn't really have much to do with air being hot since it's photons.
1:40
I am snake
You never saw me
lmao that metal gear solid reference
I like it
Exchange of contributions
an absolutely remarkable thing
God I love heat transfer hope one day to design my own house with two layers of concrete walls with a fiber glass insulation between them with a 5 meter hight top and a buried water tank for cold water and one on the top of the house for hot water instead of cranking up the AC all the time I HATE ACs
HOLA
Can anyone understand what she is saying 😅
Happy birthday john green
I typed grade 7 heat transfer and got this, i clicked on it as it was crash course after 5 mins i am like , wwwwwhhhhhhaaaaaa?
Bcos this was bout engineering and i am just at grade 7, anyway i really like crash course
it seems like convection is just conduction of a moving fluid.
i mean the heat follows the same principal, it goes from areas of higher energy to areas of lower energy, the heat from, say a house, moving to the air around it and causing it convect, still has the heat conducted to the air from the house and then from that air to other air and so on causing the convection.
seems like convection should be a special case of conduction and there should only be conduction and radiation.
I've had that thought before, interesting...
both are dependent on particles so yeah in a sense they are basically the same thing, but they have very different properties even though they share very similar principles
Well like she said, at the boundary layer of a fluid as it meets a solid, it essentially is conduction occurring due to the lack of movement of the fluid.
The motion of the fluid is what sets convection apart from from conduction. With conduction, the primary factors influencing heat transfer are the thermal conductivity, surface area, and the temperature difference.
However with convection, the motion of the fluid drastically affects the heat transfer coefficient. Natural convection vs forced convection will result in different heat transfer rates.
This is why you must analyze them separately. Solids transfer heat differently than fluids.
Guys, be careful. I think i saw a Snake...
where?do tell
What time ?
Akiohiro he means snek at 1:40
perfect insulation would be a 100% vacum right?
Lol that snake reference
What a beautiful accent!
4:20 h3h3
the shelf behind her is bothering me i keep thinking its going to fall lmao
If heat transfer always moves from a higher temperature to a lower one, does that mean I'm not "air conditioning the outside" when I leave the front door open?
See, Mom! I told you!
Scott Korin If the pressure inside your building is greater than the outside pressure (or the inside air is heavier/more dense than the hotter air outside), then the indoor conditioned cool air will flow to the outside; Exfiltration.
Its amount is small and usually neglected in engineering calculations.
period 💅
calculate nusselt number
Little H3HE reference
she never stutters. wow.
I would still feel cold becuz my arms are bare XD at 4:29
Ashoka comes to kind.!
more like yeet transfer
yes
Evaish ROBLOX gaming Yeet
You forgot to mention that this seemingly isn't needed for schools because **** kids.
I came here to see if this video could help me understand what the hell is going on in my heat transfer class. I did not expect to see such a beautiful lady. Where is she even from lol
i watch them
Shifty shelves...hurt
Let me tell you- coolimg is a lot harder than heating.
👍👍
4:20 Ethan from h3h3
looooool
thats alot of subs she has
Your shelf gives me anxiety
You managed to take a fairly straight forward high school physics topic and make it even more complicated than reading a boring textbook. How is that possible?
Using the more layers of clothing is such a bad example...
I want to no because I am in grade four
It's better to live in cooler areays anyway. Tropical island? No. Everything produces heat. That heat needs to go somewhere. Where it should go, when the air is already hot?
It would be really nice to have some way how to force atoms to give up their thermal energy in form of ratiation. So you could basically force air to radiate and cool down. And before someone tells me about entropy, don't worry. I know about that bloody thing. And I hate it's rotten guts, because that's the reason, why most of us during these hellish months feel so miserable.
you're too fast
smokin hawt
go check out gaming with oakley it is the best channel
Too be honest I didn’t understand what she went with anything 😐
what happend to crashcourse kids
ashley muniz they ran away
As a sapiosexual: "*SMASH*--Next!....c'mon, keep 'em comin'"
:D
You are extremely based. Gg ez
The whole video, I was like, “Lady, you are a very beautiful person but you need to brush the back of your hair.” Smh but no hate just my opinion but you do you
Selling piles of likes HMU
Who else pauses to watch the text? 🤣
*THIS WAS AN IMPORTANT TOPIC FOR ME LIVING IN A HOT PLACE, BUT ALL I CAN HEAR IS HER OVER EXAGERRATED BRITISH ACCENT*
Losing quality in the content also