Are Electric Planes Possible?

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[@tod2450]

“Hey guys, don’t worry, we’ll give you a formula sheet on the exam” The formula sheet: Momentum = mass • velocity The Exam: If we were to take a Cessna plane, and convert it’s fuel source to battery power, what would be it’s ideal flight time?

[@mariogonzalez4928]

Casey Glann oh no

[@dylandepetro4187]

Idk. Approx 45 minutes to an hour 20. lmao. Add solar panels to wings and that time would increase to approx 2-4 hours. But they might have to remove bathrooms from the plane to compensate for the weight.

[@williamhosking2913]

@@dylandepetro4187 what

[@dylandepetro4187]

@@williamhosking2913 it was a joke. lol.

[@DSiren]

@@dylandepetro4187 what's a bathroom?

[@valentinegutsa8097]

Now i know what my dog feels when im speaking to it

[@31ll087]

2:57 "What is delta V" Ksp players: Whomst has summoned the almighty one.

[@justanotheryoutubechannel]

Hahahaha so true, I already knew what it meant when I started A-level physics because I played so much KSP

[@whoscatimi7590]

Lol

[@Daa253]

1:37 Talks about regular planes. **Shows a Concorde.**

[@toasterhavingabath6980]

Im making one of those

[@shaunrumints5460]

me: *falls asleep during physics* me: *wakes up* teacher: 5:05 me: *concerned*

[@monarchblue4280]

Haha so true

[@WadcaWymiaru]

Story my life XD

[@annihilator_ron7691]

2 ez 4 me m8

[@anansiackhasone3428]

Story of my life

[@danihussain3651]

JIck Jalck its not hard

[@TierZoo]

Psyched for the next episode! Always been curious how hydrogen works as fuel.

[@crackedemerald4930]

TierZoo very well. Because their combustion with oxigen makes water and heat

[@remliqa]

Unless you're using fuel cells which do not combust the H2 with O2 to produce electricity (and releasing water as a byproduct) .

[@ManneSegerlund]

Using a hydrogen fuel cell. It works sort of like a battery but uses hydrogen and oxygen instead of two metals. It is not an internal combustion engine.

[@John-lf3xf]

Shockwave Shockwave what you said. Heat energy powers the engine, water comes out the back pipe.

[@rokas8594]

why did you not research it on your own, why are you waiting for someone to hand it to you served on a silver plate?

[@dutchflats]

Did you account for the efficiency differences between fossil fuel powered engines and electric engines or the fact that liquid fuels are used during flight which lowers the planes mass as it flies on over time vs. electric powered aircraft which don't lighten their load with duration?

[@ObamanableSnowman]

Yeah, liquid fuel just makes a ton of sense for airplanes. They should just master and find ways to convert electricity to liquid fuels efficiently. That, or find ways to make solar energy or wind energy directly convert the power to create a liquid or solid field. I know they kind of already do this for some rocket fuels etc, but I haven't seen it in a way that would work for planes.

[@pandapip1]

The main problem is the sustainability. It doesn't *need* to be electricity. Quite frankly, I hope we can get some sort of biological solution to the problem. I heard that some scientists were able to turn genetically modified switchgrass into a jet fuel precursor, which would be really neat if it could be scaled.

[@fuzzywzhe]

Oh, they lighten their load. E=MC^2. M=E/C^2 - what's the differential of energy? You might be able to lighten by as many as a few nanograms!

[@RyanSmith-xb8lh]

Me 7 minutes into this video: sooooooo is that a no?

[@DylanBegazo]

Basically he’s saying battery energy density isn’t dense enough currently to be a solution unless someone improves battery density enough to become an answer.

[@user-pq9gy3fq1q]

@@DylanBegazo that's good if that's the only problem because as it stands everybody is already trying to fix it. Tesla, Panasonic, Samsung, and several others are already racing.

[@TecnamTwin]

​​@@user-pq9gy3fq1q Forgot three of the biggest battery players, CATL, LG Chem, and BYD.

[@redmondokelly2464]

Really liking the new thumbnails, they look so clean and nice.

[@ramkumarsuresh]

Reddie Animates No captions = dislike

[@averagegeek3957]

+Ramkumar Suresh N V What do you mean?

[@Thomas-vn6cr]

He didn't use the unnecessary arrow that so many thumbnails love to have. :0

[@John-lf3xf]

Reddie Animates Yes, he so intellectually honest in his thumbnails. That is why he deserves respect.

[@the_kraken6549]

Whaaaaaahh? *_Ramkumar Suresh N V_* how is that a coherent or even understandable sentence?

[@ianmacfarlane1241]

What about if we use Duracell? Eh? You never thought about that, did you?

[@alveolate]

energizer is better!

[@calebkim9352]

NASA: You're hired

[@asdfghj6300]

This “real engineering guy” is just talking baby level physics, it’s not that hard but he made the equation signs so complicated, try to make him look smart, Eh~

[@dwarfie24]

Maybe we should all just ride on giant pink jumping battery powered mountain climbimg rabbits?

[@onyxrafle8066]

yea

[@mwbgaming28]

The calculations could be simplified by working out how much thrust an aircraft needs to take off, climb, and maintain level flight, then work out how much power is required to generate that amount of thrust, then multiply it by how long that level thrust will be used, then add those energy requirements together to calculate the total energy needed for a given flight

[@dustyfan22]

Me a 24 y/o with a high school education after being held back as a freshman: ah yes of course that's how you figure Delta v

[@Rin-qj7zt]

i love this. it's like all that math from school, but actually relevant to solve interesting problems.

[@clahrenssgramula4374]

True

[@mr.caswell2388]

And that's why I'm studying engineering.

[@MrComputerCoder]

All math leads to solving real problems... Can't do calculus without algebra. Can't do physics without calculus. Can't do linear algebra without calculus. Can't do differential equations without calculus. Etc

[@fieldmarshal7298]

@@mr.caswell2388 mechanical and electronic engineer rules

[@_tsunoko]

@@fieldmarshal7298 What about Aeronautical Engineering?

[@jodykemper6447]

We're sorry but you have reached your limit for equations used. Please try again later.

[@BankruptGreek]

Jody Kemper he used more equations than we use in university

[@ericcartmann]

The equations were simple. The real ones are partial diff equations.

[@Maxis196]

Take calculus it’s a lot of this stuff, not hard, it is basically just plugging stuff in. Looks scary though

[@petroelb]

Different - that's a pretty sad university right there!

[@tylergust8881]

This is the kind of math I wish I could do, just plug is equations that I seem to know off the top of my head and get the needed answer like its a trip in the park. Too bad it isn't like this at all Dx

[@spookymanbearpig]

In your formula, you forget that lift has to do with the airplanes wing area, not just the wing length. On top of that, is has quite a lot to do with the airfoil shape, so lift can actually be altered in many ways just by changing the airfoil cross-section, the sweep the wing has (in order to reduce the vortices on the wingtips - also done with winglets and sharklets), and by delaying the separation of airflow before the trailing edge. It has to do with angle of attack and whatnot. The issue with wings is, they're made sturdier by having the fuel stored in them (in layman's terms), so eliminating any storage of fuel in them can actually be detrimental to lift, due to the fact you'd have to choose a shape that is more durable, but is much less aerodynamic. Also, when you use the word "leading edge" in an aviation video, it tends to confuse people, as it has a whole other meaning in the aviation field.

[@jammingboss]

Hi, good video but I noted two small mistakes. 1) (delta x) /t = v, not delta v. Delta v represents the acceleration, not the speed. 2) Doubling the mass, will not increase the power demand by 8. It will increase it by 4, even though there is a 2 factor in the equation. Let's say for example that P1 is the power of the light aircraft and P2 is the power of the heavy aircraft and that M1 is the weight of the leight aircraft and M2 is the weight of the heavy aircraft. If the heavy aircraft has twice the mass of the light aircraft, it means that M2=2*M1. If you plug 2*M1 in the equation to find P2 and then you divide P2 by P1. P2/P1=4 (the factor 2 cancels out).

[@mattfayne9691]

Wrong! Vector-v of the standard delta within the given range of p - xrt120 over vex factor 2, is the precise analysis of any range given at par levels of accepstance, with all guidelines of sub-par equasions at exact values of 10, but not exceeding 12, but between values of particle norms of anything in the middle of whats not core value at relative transitioning. Depending upon what is, might be or could be, given everything it is and should be.

[@jammingboss]

@@mattfayne9691 lol trolling hard

[@mattfayne9691]

@@jammingboss Sorry if my knowledge was above your pay grade.

[@TheBoneCharmer93]

I absolutely love your videos. They never feel rushed but rather polished. Yes, I read many books to learn the concepts. However, nothing will link these concepts to real life like the way you do my friend. Invested in Brilliant after seeing you recommend it with heart countless times and it is worth every cent.

[@RealEngineering]

That's nice of you to say, because I literally only finished this video 30 minutes before it was published. All my videos are rushed!

[@valerie80yearsago90]

Real Engineering if it is well done, that doesn't matter. I'm sure you check your videos over multiple times before you upload it.

[@zissgoo2571]

Real Engineering I really enjoy watching your videos they have taught me a lot about engineering and physics they are always teaching me something new, have you ever thought of making a video about the mechanics of nuclear reactors?

[@jackchang4054]

The video are good, and I do appreciate them, just that sponsorship kinda make me very uncomfortable watching this, it feels like being brainwashed, pateron kinda feels better, also, What's with the similarity to whendover productions

[@jz4774]

jack Chang wendover and him are friends.

[@yrslimitz8065]

U lost me at triangle

[@Km12345rrrr]

Triangle is change, also known as delta

[@ls05-99]

He lost me at airplane

[@goose9246]

The triangle is change in

[@DJ-ie7ps]

You must be the 2.9%

[@nickhopkins73]

YRS MUSIC whats funny is that honestly this video is a pretty basic intro to much deeper aviation mathematics

[@oferkrupka]

"I've got an idea for electric jet" - Elon Musk to Tony Stark in Iron Man 2...

[@Future-Wolf]

We have only to wait. He will handle that!! ;)

[@joshhayl7459]

🔴 It cannot be a "Jet" if it's electric, by the very definition of the term, "Jet"- engines burn fuel. it would have to be a 'Ducted-fan' configuration.........

[@janstankiewicz9816]

@@joshhayl7459 Jet has many definitions, and while on its own the word is colloquially used to refer to a aircraft powered by "jet engine"; there are words that are used with it to denote a more specific meaning, for example "jet propulsion", "jet stream", "jet engine" - so adding a qualifier like "electric jet" is sensible and understandable to a lot of people. According to biologists, some cephalopods utilize jet propulsion to quickly move around in the water. Don't try to tell me they burn fuel too ;)

[@joshhayl7459]

@Jan Stankiewicz , 🔵 Perhaps you could provide me with a link to an "Electric jet aircraft", as I am unfamiliar with anything that fulfills that technical-description.

[@janstankiewicz9816]

@@joshhayl7459 I thought they were only a concept, but I found a video of a working prototype just by googling. It's called Lilium Jet. Link below. In return, would you be so kind to provide me with a link to a definition of jet that specifies it needs to burn fuel? kzbin.info/www/bejne/o5uke4qop8aHgdU

[@toxik420]

Another thing worth pointing out is that the amount/weight of the kerosene decreases as it is being used while a battery pack weighs the same wether it's at 100% or 5 %

[@erbro]

There's a joke about Belgians I particularly like (I'm Belgian btw) The Belgians invented an electric car. Costs 1 million dollars though. 100k for the car, the rest for the extention cord.

[@matthewgoodman7588]

Why specifically Belgians?

[@GodFirstnl]

Matthew Goodman Dutch people always joke about Belgiums.

[@lefr33man]

The belgians are the target for jokes from all their neighbors. It's all in good fun.

[@erbro]

Europe is a strange continent. In several recent video games the Russians are the bad guys. Why? If you make the French the bad guys, they won't buy your game. The Russians don't mind, they will buy your game anyway. In the same way Belgians don't mind being surreal idiots... Well, because basically we are Lol

[@erbro]

Lolol

[@fakshen1973]

Hold on a moment... as the conventional aircraft burns fuel, it also becomes lighter. The electric aircraft's weight would remain the same. The performance of the conventional aircraft would increase over time as the amount of fuel on board burns and exhausted through the engines.

[@f-j-Services]

yup. I always would wonder as a little tiny child, "Does it burn more fuel to have a full tank, rather than a quarter tank... hm?" lol

[@ecpgieicg]

+34486 This is exactly why usually planes don't fly with a full tank. They carry enough fuel + contingencies.

[@Ohnonomomono]

That's true. But turbines have a vastly different efficiency curve at take-off (max power) and cruise (around 60% power). Turbines are burning inefficiently while cruising, sometimes their carbon footprint actually rises at altitude. Hybrid-electric, battery/fuel cell electric do not have that issue.

[@ecpgieicg]

+Ohnonomomono The reduction of fuel efficiency with increased altitude is due to air density change, as described in the video. It applies to all aircrafts. But yes, different types of jet engines have different ideal altitude (ie. air density) and air speed.

[@joosttovitch]

Maximum efficiency is at full power, and low outside temperature. Calculations here are perhaps true, but definitely not used in aerospace engineering in terms of performance. Check out the Breguet Range Equation. web.mit.edu/16.unified/www/FALL/thermodynamics/notes/node98.html

[@KristofLossie]

“Looking at the demographic breakdown of this channel we can go a little deeper” 😂🤣😂🤣🤣😂

[@chuzzywuzzy9545]

Did you notice over 97% of viewers are Male? And liberals say that the number of female engineers is sexist. They're just not interested.

[@faraichireshe4709]

hahaa! For sure.

[@someotherdude]

It was such a stupid thing to say- a mind that dismisses 30+ people is pretty shallow. (if that's how he meant it)

[@dominicesposito4394]

XD

[@superskeg]

I think the implication is millennials are smarter but the demographic data might be flawed because boomers, AKA the generation that put men on the moon, are less gullible and less likely to share every detail of their personal information or maybe they're tired of technology stuff having spent their careers fighting the cold war and building the infrastructure we all enjoy today. OK boomer, thanks for actually doing something.

[@ryansamarakoon8268]

4:46 alright boys, we gotta start launching as much of earth into space as possible so we can reduce the strength of gravity. Who's with me?

[@bigdanslivestreams4060]

I'm in!!! 😁😁😁😂😂😂

[@sharkycat1096]

Start a new channel called “Simple Engineering” for us plebs

[@laur-unstagenameactuallyca1587]

PLEASE! lol

[@ahuman8407]

Actually though, we want simple engineering.

[@blueonyt7637]

This video is very simple

[@jorelmendoza8842]

ask jundroo for that

[@orangesnowman7137]

BlueON YT not for everyone

[@koriko88]

8:56 This guy seems to have MUCH bigger problems than equations. Lol

[@sushiboxchris]

@ninjarawr21 wtf

[@agnieszkakrakowski8299]

ninjarawr21 shut the fuck up cronge normie reeeeee

[@ahsanrajwani]

@@sushiboxchris ha

[@abcxyz123]

@ninjarawr21 well, you seemed to have missed the comedy in the original comment...

[@drone_better7757]

What could be bigger than equations?

[@K9TheFirst1]

There is another issue with Batteries, specifically with Lithium-Ion: Capacity decreases with use. Every time you recharge the battery, just a little bit more of the battery's capacity is lost, and thus the next charge won't last as long for the same amount of draw. It might not be noticeable at first, but if your Cesna is barely making it's trip on a single charge, eventually the plane will lose all power in the middle of landing, and after that it starts dying mid-flight. And if you somehow not died at this point, the battery won't hold a charge at all. We've all seen this with out smart phones. So you would only get the maximum range out of a battery-powered plane so many times before that battery needs to be replaced. And while battery recycling is a thing (and is why, for cars and boats at least, there's an additional fee for buying a battery if you aren't bringing in a dead one), there is still an inevitable waste that will happen.

[@tilehead4640]

Just stumbled upon this channel recently and I'm impressed with your aviation videos and the level of detail. Thanks for providing quality content!

[@leok.2898]

Quality content? This should be flagged for mininformation. His grasp of simple mathematics is sorely lacking!

[@031films8]

Another problem is that the batteries become dead weight while burning fuel the airplane becomes lighter and it can fly further and higher.

[@KevinBE87]

Starts watching. Sees explanation about batteries being 40x heavier than kerosine. Makes sense, I'm happy I know this now. But starting at 2:12 I felt more and more stupid and I should go back to my coloring book :(

[@60darklord]

Kevin Bauwens taking AP physics in highschool wasn’t completely useless... just kidding. Idk what he’s talking about still. Sos.

[@joe4398]

I looked like I knew what he was saying but deep down I was like fuuuuuk....

[@hansiraber]

8:55

[@flostrasser2994]

Wait ,how old are you ? Im 14 and i understood everything but im a bit of a geek. Anyway its probably because you didnt do physiks in a while.

[@zodiacfml]

Don't worry it is all fluff to lengthen the video. The main point here is that batteries will not work for long range planes. However, I think the electric planes will be the future. The thing this video is missing is hydrogen, hydrogen fuel cell systems. Power density of this just dwarfs any kind of fossil fuel. If we go overboard with renewable energy, we could be storing them as hydrogen.

[@joe-xk8nl]

"She's totally giving you hints!" Her hints: 3:19

[@toasterhavingabath6980]

im Very confused and dont know what they mean

[@pauld.b7129]

One important factor you also forgot: Charge time. What would the charge time be for 200,000kg worth of batteries? "Welcome to London, we'll see you next week when the plane has recharged" 😂

[@petrkubena]

Same as your notebook battery, car battery or any other battery (roughly one hour assuming good enough power source). Whether you charge single cell or thousand cells in parallel does not matter much.

[@michaelesposito2629]

Petr K Lol this is an extremely ignorant comment. Do you have any idea the type of power and infrastructure that would be required, to charge a plane full of batteries? I can’t believe you compare that to a laptop that can be charged from a standard wall outlet. Electric cars take roughly 8-12 hours to fill up.

[@petrkubena]

@@michaelesposito2629 Because you don't understand my argument obviously. I was also talking about car battery (think EV). That is 3 orders of magnitude larger than your laptop battery ... yet it takes roughly hour to charge. Same as your laptop. Think about it for a while. Of course - battery for something like 737 would be again order of magnitude larger (or more) and similarly it would need order of magnitude (or two) larger charger, than some Tesla Supercharger. But that can be done. Limiting factor is again speed at which you can charge single cell.

[@michaelesposito2629]

Petr K I’m done. I can’t have such a complicated discussion with someone clearly so ignorant. And stop using “orders of magnitude” as If you understand what that means

[@petrkubena]

@@michaelesposito2629 Ahh... I see. you are an expert troll. You win then. Maybe just out of curiosity (if you are only making a real great impression of a troll) - if largest notebook batteries have 100Wh (ie MB Pro) and largest battery in Tesla (so far) has 100kWh, how many orders of magnitude is that ?

[@marcwenger9424]

Very informative. Another interesting point is that airplanes get lighter in flight as they proceed, whereas battery mass doesn't change. This results in airplanes departing and arriving with the same mass. On conventional aircraft that would be an overweight landing. Battery powered aircraft would need reinforced landing gear and therefore have added mass

[@auspiciouslywild]

Marc Wenger Maybe the plane could drop some of the batteries 2/3rds of the way out on a paraglider or something ;) To do something like the 747 to 787 electric would require a massive rethinking of the whole aircraft so it’s not totally unreasonable to imagine something crazy. I do think that long haul airplanes will need some kind of fuel for a long time though. But maybe we could gain more efficiency with some kind of hybrid design. If we can cut fuel consumption enough we could use biofuels.

[@kennedymcleod1479]

Marc Wenger Plus longer runways will be necessary to prevent runway overruns due to weight increase at landing

[@drabberfrog]

@@auspiciouslywild The logistics of dropping the batteries seems risky and difficult.

[@Cynsham]

@@auspiciouslywild We've been using hybrid design for a long time now. The current 787 Dreamliner is the closest thing to an "Electric airplane" we've ever built on the scale of a commercial aircraft, as well as the fact that it is the most fuel efficient large airliner ever created. Compared to the Airbus A380, which is its main competitor, the 787 was shown to be about 60% more fuel efficient.

[@Tundrah648]

Np, lets do nuclear airplanes instead.

[@tfowlis6659]

It's funny because the US actually tried to do that. The main issue though was thrust to weight, as a nuclear reactor is wayyyyy to heavy for a plane, and thr idea was to basically just heat air to create thrust.

[@Randomguy-wd5lw]

@@tfowlis6659 And nuclear reactor are that heavy simply because of all the shielding need to block those pesky neutron!

[@vampov]

@@Randomguy-wd5lw Actually Russia and the united states both put reactors in the back of planes to see if they could carry the load. The problem just became pointless when you could nuke your enemy with ICBMs much cheaper and easier.

[@Randomguy-wd5lw]

@@vampov I think you didn't finish your comment.

[@Mike-zl4km]

Us had a plane with a reaktor onboard but it did not power the plane. The Russian actually had a working plane that was powered but the nuclear reactor. The main problem though it was puking out contaminated air and it had so little protection. It did not even protect its own crew..

[@johnjohnson1191]

Yes, given two criteria are met: 1. Your battery banks are of such a volt/ampere output and of such capacity that the weight of your power supply does not exceed the maximum load of your frame or the maximum lift of your wings. 2. That the electrical motors you use (propeller this type) output a significant enough amount of thrust that the drag coefficient of your lifting body is outweighed and a significant enough amount of lift is generated that you can gain stable flight. The alternative to a simple propeller is essentially a fuel less jet turbine, where you have an air intake that compresses air when moving at a certain speed so that the pressure inside is significant enough for effective heating of the air using coils so that the thrust of the engine is great enough to again, overcome the drag coefficient of your lifting body and provide enough lift for stable flight. The main problem with this is that you have to be moving at a specific speed threshold before air compression becomes practical, thus you essentially have to use turbines only up until this point, unless you can design a heating system effective enough that it can use uncompressed air. In conclusion: This is a great engineering challenge as currently even the most weight efficient high capacity batteries are most likely not capable of providing the sustained power output necessary, beyond that an entirely new set of engines have to be developed, as almost every single plane has relied on one of four key engine types with some variations and improvements. However there are several alternatives to batteries: Solar planes, however surface area vs thrust has to be massive because solar panels output a tiny amount of energy in comparison to say, jet fuel or batteries, which means that you'll be lucky to reach 100mph because your drag coefficient is going to be bigger than this post. The other option is electrical nuclear, but that runs into the problem of radiation shielding, and essentially you'd need a lead brick as a plane, or you'd need some sci fi radiation energy shield. Beyond that good luck finding room for your generators or all that water and piping (if you're using BWR). The only real way this could possibly be practical right now is to use a conventional jet engine for takeoff and landing and use electrical engines for cruising using the electrical jet I described above, even so you'd have very limited range unless you utilized perhaps non combusting exothermic chemical reactions to heat the inner skin of a jet engine, which runs into a whole other range of problems and may be less ecologically sound than even just regular jets. All in all, practical some day soon? Yes given that energy storage technology continues to advance. Practical today? No.

[@prathameshacharya3457]

I love your channel's aesthetics. Where do you create all your animations?

[@rockskate15]

1:52 97.1% male and 2.9% female... wow.

[@w0mblemania]

Keep in mind that, statistically speaking, more than 2.9% of males portray themselves as female online. So, that gives us a negative value for female representation here. Which is about right. But I'm sure someone will stop me and tell me that umpteen million women really are interested in engineering, it's just that this channel only allows males. Or something about privilege.

[@AlessioSangalli]

Yeah the creator of this channel must make a better effort to attract women! Instead of concentrating on creating great content. [sarcasm]

[@OriginalPiMan]

w0mbles And how many women portray themselves as men?

[@TheTariqibnziyad]

Anthony Gomez low average IQ for women

[@djordjezivic2481]

proves we are nerds

[@simcopter1821]

There also is a turnaround problem as well. Fossil It is very quick to refuel and easy to drop fuel to lower the weight of the plane in emergency situations. both of these problems would need solved as well.

[@outshimed]

Could have standardized battery packs, swap them out at the airport for them to charge and put a charged one in, take right back off. Like propane tanks. That could theoretically be even faster than refueling.

[@athr_blu]

Might be a bit dangerous, li ion battery if mishandled can catch fire, jet a in comparison has to be atomised in order to catch fire.

[@Gabdube]

Harish Rajan Everything with that level of energy concentration can ignite when mishandled. Even jet fuel.

[@athr_blu]

GabDubé yes, i didn't say jet a is not volatile, but no one is in a hurry to swap it around, imagine if u want to swap the batteries they have to be removed by a forklift of something, which increases the danger of the batteries being mishandled

[@adamthomas7542]

Hi mate love your videos, what programmes do you use for the animations?

[@MB-el2um]

This is like the 3rd time this guy used footage from my country. 1:03 Slovenia Ljubljana. Great stuff thanks...

[@setht9295]

lol, just put windmills on the plane bro not that hard

[@earthshaker3982]

LUETIN but... Damn it.

[@Steppenkater]

Beside those windmills will cause so much drag that it will consume more energy than the windmills will deliver. Simple physics.

[@koninkrijkdernederlanden8711]

LUETIN No, a mix of Red Bull and paddos works much better.

[@kvltizt]

We kinda already do that. Look up an APU for passenger jets.

[@vaughanxaviermusic]

buddy cant take a joke

[@jibeneyto91]

Good video but using an "x" to denote multiplication next to an "x" that's a variable killed at least three cute puppies.

[@nicholaslau3194]

I was like: "Since when did work done become a cross product?"

[@carsonm6140]

Great video! I actually have worked a few summer internships in the eflight field, and this is exactly the big concern at stake for the industry. Although I think it is misleading to say that doubling the mass increases power requirement x8 (5:20). If you are comparing the doubled mass case to the original, then the 2 before the M in the equation cancels, leaving only a four-fold difference.

[@dankujaneck7376]

2^2=4. also at 5:05 "Flift=Fdrag" should be "Plift=Pdrag".

[@gurvzz]

The problem with changing to renewable energy in planes is the constant weight, normally with kerosine the fuel would burn, reducing weight. This reduction in weight is essential because of landing, aircrafts need to be in a certain weight limit to land safely, because if they are too heavy then the runway they land on is too small. This is a problem with renewable energy because the weight never changes, demanding much longer runways, and emergency landings to be extremely dangerous. This is one of the main reasons why the aviation industry can’t change.

[@ch98hb]

97.1% Male Viewers, there is more sausage on this channel than on a german bbq party

[@chimingw]

Wtf

[@outsidethecave3016]

we're talking about engineering, not about washing dishes

[@maximiliankammler3970]

In Aachen*

[@texasabbott]

Please explain in layman’s terms about the quantity of sausage on this channel.

[@rooron3152]

LMAOOO actually i'm a woman and this made me laugh

[@josiahmartin329]

one thing you forgot: for prop aircraft, fuel usage is proportional to power for jet aircraft, fuel usage is proportional to thrust. that is why, when determining maximum range, you look at the power graph for prop aircraft and the thrust graph for jet aircraft.

[@jonibeYT]

Why is that?

[@josiahmartin329]

@@jonibeYT jet aircraft turn fuel directly into thrust by spitting the burned fuel out the back. Prop aircraft turn fuel into thrust indirectly by spinning a propeller. This makes them less efficient when the air is thin, or when the plane is already going fast. flightacademy.info/aviation-power-curves

[@jonibeYT]

@@josiahmartin329 Jets dont spit out the fuel but they heat up air which expands and that way gets pushed out of the back. Maybe the point is that in thinner air the jet can heat up the tinier amount of air more which results in the same thrust while the propeller is limited by its tip speed and the sound barrier because if that isnt the case the propeller can just spin alot faster because of the reduced drag

[@rickycool6083]

Jets require fuel, the theory here revolves around electric propellers.

[@MarcusMIDI]

This video is brilliant, thank you so much :)

[@lombardo141]

Thanks for reminding me why I failed physics in high school. 👀

[@pierro281279]

One HUGE drawback of such a low power density energy, is the landing weight since you don't loose significantly weight over time. On traditional airliners, you can't land safely with a full fuel tank. You can't either dump the batteries in case of an emergency. PS: Love your vids !

[@xponen]

nowadays modern airliners can land with full fuel tank, I learn this from @Mentour Pilot . He says fuel is really expensive to an Airlines, they really want to keep it if possible.

[@antalz]

The problem is more that when you have an emergency, you really want to dump fuel and return, to set yourself up for an as easy landing as possible. Would you go for a severely overweight landing with inoperative slats, flaps, spoilers or thrust reversers? No, you dump fuel.

[@Demonslayer20111]

xponen_ not according to the tcds and far regulations they can't. All aircraft whose takeoff weight exceeds maximum landing weight are required to have jettison systems, (which all modern airliners have) because of the simple fact that they can NOT land with a full fuel load.

[@airindiana]

It’s a good point but just a bit of inside info. On aircraft where Max landing Max is less than Max take off, you have to achieve that mass to land with in normal operations. However, you absolutely can land over weight, as long as the landing performance allows it will be perfectly safe. An instance would be if you are required to land immediately, such as smoke on board. Commercial Aircraft are tested to land at Max take off weight for safety reasons. For instance a serious fire after take off that requires an immediate landing. Normally post any over weight landing, an inspection is required by local engineering on stress prone areas. It’s actually about preventing long term stress from repeated over weight landings rather than damage from a single landing. Hope that provides a bit of colouring in.

[@Demonslayer20111]

airindiana and runway overruns. Landing g rolls are longer than takeoff rolls

[@markschultz2897]

Doubling the mass does not increase the energy 8x. Since no matter the mass of the plane the mass square is always doubled (for e.x. 1^2=1 1x2=2 2^2=4 4x2=8 8/2=4. The energy increases 4x.

[@badezimmertv1457]

I think 8-fold is an idiom.

[@lordspork7524]

Mark Schultz shut the fuck up

[@asiastreets4032]

I was thinking if you have a cube, and increase all sides length with x2it will be 8 times volume

[@spacecadet35]

In reality increasing the mass seems to have little effect. A 747-SP weighs four times as much as a737 MAX, but only has three times the engine power. They really screwed the pooch on this clip.

[@The_Best_Caden]

yall some effing scientists

[@yamanatoo]

Nice video thank you. @5:19 the mass component of this equation is only squared (not doubled), doubling the mass increases power requirement 4 fold not 8.

[@henrybeare8788]

Just found this comment after scrolling for miles down the comment section thinking 'why hasn't anyone picked up on this!'. I think Real Engineering has got mixed up as the factor of 2 has just been introduced into the equation. The factor of two however can just be assimilated into a constant, k, and power will still be proportional to the mass^2. So doubling the mass, increases the power 4 fold.

[@lucasjoona2182]

Hey, i really appreciate and I would like to use some of this info in a school project om working on which is about electric planes, so I wonder where you got your sources from?

[@BigRodd91]

He pulled all the info out his butt! ☺️🤪

[@the-lag-gamerita5446]

@@BigRodd91 no he didn't ,you are scientifically illiterate if you came to this conclusion.go to school kiddo

[@BadPC]

This channel is the only one I choose to be notified about

[@patrik5123]

Same here. Well, CGP Grey too, but he takes fucking forever to post anything.

[@RedStefan]

Well done sir

[@AlRoderick]

Batteries also don't get lighter as they are used up, which also factors into the range.

[@Sir_Budginton]

Well, technically, they get a few micrograms lighter...

[@111danish111]

That is certainly amusing.

[@Demonslayer20111]

111danish111 how? When fuel is used, it's gone, which means the plane is lighter, meaning g it can fly higher and faster which increases the range. Just like your car. Remove weight=better fuel economy

[@111danish111]

Totally correct I meant Hanif Shakiba's comment was amusing.

[@mtolives]

You can eject the spent batteries silly

[@notdaveschannel9843]

0:49 I think Boeing are mainly in a battle to make a plane that doesn't f*cking crash.

[@fieldmarshal7298]

*Ah fuck. Not again* -Boeing

[@JoshyDMCOfficial]

You are over 50,000 times more probable to get into a car crash than into an air crash.

[@saocxdc210]

@@JoshyDMCOfficial Very true, more ppl die in car crashes happened than plane crashes. The plane crashes just look more tragic Edit: it's actually more tragic

[@grassh0pper]

@@saocxdc210 with a car crash, there is always that hope that you'd live and people don't usually see it coming, or they do, but still maintaining hope. With a plane crash, well it's hard to have any hope when a typical plane crash kills everyone. A plane crash though damn!! Must be fucking terrifying. Fuck, it happens in areas that cars have no business being. Nightmarish areas that you wouldn't hell dream of journeying with a car. My lord yo!

[@saocxdc210]

@@grassh0pper I agree with you on that point. That's one of the biggest weakness in aviation, no one can save any plane airborne

[@declandickson2839]

oh.. and I was just gonna say.. step 1: take a B-29 Superfortress and remove the Wright R-3350 engines. 2: and replace them with a new giant radial electric engines. 3: remove all gunner positions, gun turrets and the bomb bay. 4: replace them with luggage and passenger compartments. 5: replace fuel tanks with massive batteries and add modern day radio and radar. 6: provide windows in the passenger compartments. 7: change nothing else. (the cabin is already pressurized, and a B-29 airframe is built to withstand flak and heave caliber machine guns. so I don't think it will have an issue dealing with some extra weight. and the controls are normal hydraulics so just hook them up to a computer). 8: show finished prototype to Boeing. 9: have them call it the B-29E and revert their factories to 1945. 10: make Boeing give you 1% of their income from the new airliner. 11: PROFIT!!!

[@dontlikemycomment1771]

better than my science class

[@StephenHung2274]

NS RIDER of course what are u talking about?

[@aaron___6014]

NS RIDER but still boring.

[@AngryArmadillo]

5:20 “Doubling the mass will increase our power requirements 8-fold.” This is incorrect. The factor of 2 in the power equation is present in the calculation for both the lighter and the heavier plane, meaning it can be factored out. Doubling the mass increases our power requirements by a factor of 4.

[@shoofle]

Yeah that made me go 🤔🤔🤔🤔

[@reybandwidth715]

Russell Schwartz yea I definitely caught that too I was like hmm 🤔 soon as I heard that

[@mellowjello2593]

Yeah I don't get how he can think that. "it's not only squared but also doubled" wtf?

[@zodiacfml]

Glad not to listen with all his fluff to lengthen the video. He shot himself on the foot with all the equations. However, I think the electric planes will be the future. The thing this video is missing is hydrogen, hydrogen fuel cell systems. Power density of this just dwarfs any kind of fossil fuel. If we go overboard with renewable energy, we could be storing them as hydrogen.

[@tilmerkan3882]

@@zodiacfml yeah, but sadly lose most of the energy in the process of making it and using it.

[@NERDXspace]

I am 13 and your vidios are the only way I can understand these complex equations keep up the good work! Thank you!

[@theotherguy6951]

The other issue is that the propulsion for electric planes will be propellers driven by electric motors. Propellers are not as efficient as conventional turbofans are when flying thousands of miles. Propellers can't reach the speed and altitude a turbofan can. This means electric planes will experience more drag since the air is denser at lower altitudes and it can't fly above any potential storms which will be uncomfortable for passengers who's flight times have already been doubled due to the slower cruising speed of electric planes. I heard that under 50% of all flight tickets sold in 2018 were for flights under 500 miles where even turboprops are more efficient than turbofan planes for flying that distance. So electric planes can definitely dominate that role but I would expect the kerosene powered jet engine to continue filling flights over a thousand miles.

[@BjornMoren]

To use simpler formulas, you can look at figures for fuel consumption for an airplane. A 747 consumes around 4 liters of kerosene per second traveled. One liter of kerosene contains 37 MJ of energy. A 7 hour trip uses 4 * 3600 * 7 * 37 = 3,700,000 MJ of energy. The Tesla Model S batteries are state of the art, and have an energy density of 700 MJ/ton. Replacing the kerosene with such batteries will give a battery weight of: 3,700,000 / 700 = 5,300 tons. Compare with the maximum take-off weight of a 747 which is around 400 tons, not even in the same ballpark.

[@abdulazeez.98]

Björn Morén Man you made it soo much easier.

[@lhl]

Yeah this video had a lot of pretty irrelevant math when all you need to do is compare specific energy - about 43 MJ/kg avg for aviation fuel, and about 1 MJ/kg for current state of the art production LiCoO2 batteries (Li-S promises doubling energy density to just under 2 MJ/kg). One thing worth noting, a Cessna 172 uses a 160-180HP (120-134kW) w/ a 117kg dry weight, while a 120kw electric motor will only be around 25kg. The Lycoming O-360 engine on the Cessna burns about 30L/hr, so a 4 hour flight would be 120L of fuel, about 96kg (0.8kg/L) - that's about 4.1 GJ of energy to produce @ 120kW, 1.7MJ of thrust (sounds about the right efficiency for an ICE) and a final motor+fuel specific energy of 19.4 MJ/kg. An electric motor should be 85%+ efficient, and you probably can realistically only discharge to around 80% before falling below voltage, so you'd need to carry around about 2.5GJ of battery for the same flight. The motor weight is a rounding error for doing our calculations, basically, you'd need 2500kg of LiCoO2 batteries, so about 12X the weight. HFC is probably an option should be about 5-10X performance of battery systems, although that's largely dependent on how small the energy subsystem is (I haven't looked close enough at what the state of the art is). There are also some mid-term battery improvements, like solid-state that would probably get you there as well. Heck, if you could get lithium-air working, you could probably beat out jet fuel performance...

[@BjornMoren]

lhl, good of you to also include fuel/motor efficiency in there. What is HFC? Sounds interesting.

[@lhl]

Björn Morén Hydrogen Fuel Cell, what I assume the end of the video is talking about (liquid Hydrogen really isn’t a realistic for planes).

[@katzen3314]

I don't think that was right at 5:16. Multiplying the mass by 2 will cause the power to multiply by 4, not 8.

[@katzen3314]

@Bob Saget Say you had M=2, you would get 2*(2)^2 = 2*4 = 8 And then M=4 would give 2*(4)^2 = 2*16 = 32 Double M, and you quadruple the result, because it is proportional to M^2 and multiplying by any constant will have to be done in both calculations. 2M^2 is proportional to M^2, and 43875M^2 is proportional to M^2. Any constants involved don't change that, because they remain constant.

[@SawedFps]

@@katzen3314 🤔😂

[@main-main6186]

weight is shared equally on the wing, hence it will result in 4 instead of 8, 8/2

[@ncedwards1234]

But he just says double the power not double the mass. This is the difference between 2*m^2 and (2m)^2. And the former is what he puts into the formula so I don't get why he would say times 8 when that doesn't line up with the actual equation given. Plus at 5:06 he directly says "double our power requirement," and not "double our mass and multiple by 2 after." And before someone says something about the mass of the fuel, is doubling fuel weigh really going to double the plane's mass?

[@vincentgoudreault9662]

Actually, the reason is due to the need to also increase the size of the wing to accommodate the lift required for the increased mass, or to increase the speed with the same wing area. And if you fly faster, you are using the energy at a faster rate over a given distance. The conclusion stands, but it is embedded in the equations.

[@Cynsham]

I work at an engineering company that repairs and maintains commercial and cargo aircraft, I'm not exactly sure what most people think of when they hear the term "Electric Airplane" but the current Boeing 787 Dreamliner is the closest thing humanity has ever built to being an "Electric Airplane" on the scale of a passenger jet. In pretty much all other commercial aircraft, you've got 3 different hydraulic systems, left, center, and right, which work together to support all of the primary flight controls, normally fed by turbine driven pumps on each engine gearbox and 2 dedicated pumps for the center hydraulic system alone. However, in the 787 it still has the same 3 hydraulic systems, the primary power source for the left and right systems are engine-driven pumps mounted on the engine gearbox. In addition, the left and right systems are each powered by an electric-motor-driven hydraulic pump for peak demands and for ground operations. The key difference between the traditional and 787 hydraulic system is the power source for the center system. In the traditional architecture, the center system is powered by two large air-turbine-driven hydraulic pumps, which operate at approximately 50 gallons per minute at 3,000 pounds per square inch to meet peak hydraulic demands for landing gear actuation, high lift actuation and primary flight control during takeoff and landing. During the remainder of the flight, two small (approximately 6 gpm) electric-driven hydraulic pumps power the center system. In the 787 no-bleed architecture, the center hydraulic system is powered by two large (approximately 30 gpm at 5,000 psi) electric-motor-driven hydraulic pumps. One of the pumps runs throughout the entire flight and the other pump runs only during takeoff and landing. The higher pressure of the 787's hydraulic system enables the airplane to use smaller hydraulic components, saving both space and weight.

[@p.k.r400]

intercontinental high-speed trains linked to the Belt and Road Initiative

[@cmuller1441]

Wrong. At 2:30 the work is the dot product of displacement and the force. For an horizontal flight the work of the lifting force is ZERO. en.wikipedia.org/wiki/Work_(physics)#Mathematical_calculation The only forces that need work is the drag. The wing are not perfect and generate a certain % of drag proportional to the lift. It in the range of 1/15th to 1/20th. en.wikipedia.org/wiki/Lift-to-drag_ratio So somehow some of the drag is proportional to weight but all your calculations are a bit strange... Of course this is not all the drag. There's some because of frictions, the aerodynamics of the fuselage...

[@policeman0077]

you are right

[@allmycircuits8850]

Yup, very strange equations indeed. My eyes began to fill with blood when he divided DeltaX by just t, not DeltaT (it's very ugly way to write derivative!), than he named velocity he got with DeltaV, which is totally wrong, there should be just V. But the final straw was to consider lift, not drag, you're right.

[@cmuller1441]

PolarBearVodka007 That's the whole problem this video tries to solve... I would do it another way. Imagine you have a working plane and add extra weight. You have to increase lift. The best way is to increase the size of the wings. Of course this also increases the weight. Also some structure is needed. At the end of the day you have to add even more wings... Conclusion: it's not really linear. A point that was not taken into consideration is the volume. For the same energy you need a lot of space. Electric planes are possible (see solar impulse) but at the cost of huge planes and very low speeds. (One of the trick is to use solar power to increase the energy available and also increase of altitude to store energy during day and going down slowly during night)

[@cmuller1441]

PolarBearVodka007 and BTW yes even considering his method it's x4 not 8 when doubling the weight.

[@cmuller1441]

Another point is that the equation has 1/L^2 factor but if you increase weight a lot you have to use bigger wings or you just can't take off and cruise at decent speeds even with flaps. To simplify things let's just say the lift doubling needs a doubling in wings area so an increase of sqrt (2) of L. So doubling mass will x4 the numerator and x2 the denomitor. At the end you just get x2 power with his equation...

[@OhFishyFish]

Can batteries melt steel beams?

[@averagegeek3957]

Depends on their energy output.

[@clee8768]

Yes. kzbin.info/www/bejne/mHKldKmrmKx0isU

[@jirkavebr-czmapper8059]

If they are on fire than most likely yes.

[@crhuskey]

If that's the story the government needs to explain some buildings collapsing, then yes.

[@hendrayudhapratama1027]

everything is possible if you believe in it

[@csbanki]

I'm a bit concerned that pressure difference around the wings were never mentioned. Maybe it's included in that downward air stream that was mentioned around 4:20 but I felt like it's excluded. Very interesting video none the less, thanks for sharing!

[@marauder3006]

RE: how many calculations do you want? Me: yes

[@gibbethoskins8621]

I'm just watching this in the hope that one day there will be a drug that allows me to understand what he just said.

[@ConstantChaos1]

Until NZT48 is made I'd suggest large quantities of adderall and wasting at least one semester in a engineering program at a good school I dropped out at the first semester but I kinda got it (full disclosure tho newton is my great×8 uncle tho)

[@mohithrajamani637]

I smoked a very large bowl before watching this and I'm stoned out of my mind but trust me when I tell you this still got me like ._.

[@Antbal-sf2wy]

I already knew what he was talking about but it still gave me some trouble the way he set it up.

[@drone_better7757]

Ketamine, you must take. Run over minorities in your 2001 Honda Civic, you must. Recognise the legitimacy of the State of Israel, you will not. Make sense, the equations will.

[@saintsyndicate5435]

@@drone_better7757 10/10

[@mr88cet]

Minor nitpick: Strictly speaking, Energy Density is energy per unit volume not per unit weight. Specific Energy is energy per unit weight. “Specific Energy” is energy per unit weight.

[@gj6792]

Sorry, there are several mistakes in the equations and the explanations of their meaning and underlying physics, starting from the point where velocity is denoted as Δv. However, the bottom line is correct: Batteries do not have the energy density to compete with current jet engine technology; storing energy in hydrogen instead of batteries and converting it directly to electricity through the use of fuel cells could get us there.

[@jacobshaw808]

G T Thank you! I had to scroll way to far to find someone who said it.

[@pebbles8735]

there is a part missing. You didn't take into account that electric engines are able to convert about 70% of the energy they get into momentum. However the classic fuel engines are way less efficient. This makes the cessna even more legit

[@UltimateAlgorithm]

But fuel powered plane get lighter as it go, while battery weight stays the same. If you look airplane weight and balance calculation, they take this into account. This is also the reason why most plane have higher maximum takeoff weight than its maximum landing weight.

[@the-lag-gamerita5446]

irrelevant,the battery would still weight tens of tons more.

[@pebbles8735]

@@the-lag-gamerita5446 Just saying. Not saying this would be gamechanging

[@ReubenMason99]

Mass is squared and doubled so starts at 2m^2. doubling mass gives 2x(2m)^2 = 8m^2. 8m^2/2m^2 =4 rather than 8

[@Moonfrog11]

Reuben Mason yeah I was like wtf are you talking about when he said that

[@4K68]

This is such a grave mistake, he should reupload a new corrected video.

[@Heart2HeartBooks]

ue=

[@zodiacfml]

Glad not to listen with all his fluff to lengthen the video. He shot himself on the foot with all the equations. However, I think the electric planes will be the future. The thing this video is missing is hydrogen, hydrogen fuel cell systems. Power density of this just dwarfs any kind of fossil fuel. If we go overboard with renewable energy, we could be storing them as hydrogen.

[@wilcoisfrancois2479]

I understood it to mean doubling the already doubled mass would result in a factor of 8 times the Original M^2. That's how I read it...but I don't know if that's what he intended or he really made an error. Great info though.

[@oliverhughes169]

Do these formulas take into consideration that the plane gets lighter for the more fuel that it burns? And that a plane cannot land when it is full of fuel, it can’t bear the extra weight at landing. Batteries will remain a constant weight throughout the flight, so this is a massive factor when compared to burning fuel.

[@unitrader403]

Planes are engineered to account for this. If someone developes an Electric Plane (when the Battery Technology is ready) it would be very stuipid for the Engineers to not account for this.. in fact i would delegate them to design Plastic Spoons instead and hope for the best if they didnt account for this..

[@ashsmitty2244]

UniTrader THANKYOU.

[@oliverhughes169]

You’re right, though probably counting to support that extra weight will add even more weight to the planes structure, at least with current technology . It’s exciting to see what innovation will bring.

[@alexandrelemenn5269]

Great video, however I question the approximation that Flift = Fdrag, since most commercial planes (A320, B747) have a lift to drag ratio of about 15

[@dankujaneck7376]

I thought that Flift is equal to the weight of the plane and Fdrag is equal to the thrust provided by the engine. This would mean that the engines generate enough thrust that the plane could fly straight up like a rocket. I must be missing something. I'm at 5:05 in the video and will stop here until I figure out what this apparent nonsense is all about.

[@dankujaneck7376]

I think "Flift = Fdrag" is a typo. It should read "Plift = Pdrag" i.e Power required for lift = Power required to overcome drag. This interpretation is consistent with the next formula after the one at 5:05 (which is at 5:08) where the author multiplies the right side of the equation by 2.

[@parkproductions3]

Correct me if I am wrong, but I think you are confusing the power needed for lift and the power needed to propel the aircraft through the air. The power generated from the fuel/batteries goes to the engines/motors to produce thrust, not some mechanism used to generate lift. When determining the power needed for an aircraft you use P=F*V, but the the force,F is equal to aerodyanmic drag of the aircraft(Which yes is a function of CL in the nonlinear drag model) I think the derivation you showed is more relevant for a hovering craft as the power of the batteries go to motors providing upward thrust. Curious what your thoughts are....

[@skrattzerat5831]

When i saw the video I did not feel it was right. This would be the formula "L = .5 * Cl * r * V^2 * A" supporting what you have stated.

[@aGuyNamedEr1c]

I think the comparison is not completely fair, as it's putting current electric systems in vehicles using 50+ year old design, technology, and materials. It would be like installing a Tesla Model S drivetrain in a 1957 Chevy Bel Air. An electrified '57 Chevy will not get the same mileage and performance as a new car designed to maximize the electric drivetrain.

[@XGamersGonnaGameX]

5:20 "Doubling the mass will increase our power requirements 8 fold". I might be missing something, but how does this come out of the equation you just showed? I realize there is a 2x at the front, but this shouldn't change what happens when you double M_plane. For example, assuming the value of all other variables is 1 (to make this easy) you are simply left with 2*M^2. If you plug in 1 for M you get 2, if you plug in 2 for M you get 8. This is a 4 fold increase.

[@DeFlekkie]

Came here to say the same, Friedrich Nietzsche, I think you are absolutely right, the 2 will not lead to an 8fold increase, it's only the square that counts! Great video though.

[@MrSpreteng]

Wrh does 8 fold mean

[@XGamersGonnaGameX]

-James R Not even then, the 2 inside the brackets would become a 4 outside of the brackets and the same issue would remain.

[@smasher123ism]

Square cube law

[@vincentgoudreault9662]

Actually, the reason is due to the need to also increase the size of the wing to accommodate the lift required for the increased mass, or to increase the speed with the same wing area. And if you fly faster, you are using the energy at a faster rate over a given distance. The conclusion stands, but it is embedded in the equations.

[@Marnick43]

Your video just was showen on a Dutch news program. The part about the weight of the accu to fuel ratio

[@akithyren]

Nice video ! I have a question: do you remember hidrogen cars ? It would be great if you could make a video about the possibility of having hidrogen powered planes - this would really be a possibility but not enough companies are looking into it. What do you think about this?

[@smashingturnips5353]

Hidrogen? Hydrogen potato potato

[@dipeshpatel6643]

As always......informative. Thank you RE

[@khaledsarsam1]

The weight of a plane held by kerosine gets lower with the flight time, while not true for battery powered

[@DeathlordSlavik]

Which is important as the plane is expected to have shed that weight at landing time as it makes landing easier and safer with battery powered planes you would not only have to overcome the energy density problem but also the problem of having to do redesigns to fit with the fact the plane will be the same weight when it lands as when it took off.

[@twoeightythreez]

Maybe a good transitional technology would be to install a reforming unit aboard existing aircraft to make hydrogen from gasoline, which would then power a fuel cell. Then, as hydrogen storage tech got better you could just use the fuel cell. A small battery bank would be used for takeoff power.

[@hyperocket3279]

Just drop the dead batteries.........BIG BRAIN

[@latenightcoffee8417]

Plane: hey whats that? Rainstorm: thats just lightning Plane: light what?

[@99luftwaffles]

Can you do a video on Hydrogen planes like the Reaction Engines A2?

[@josephmario6816]

Engineering at it's best.....2:04 Cessna with wheels skidding on water

[@PabloGonzalez-hv3td]

Freewheeling on water it's a common maneuver but don't hit the brakes you'll dig in and flip

[@josephpayne113]

@daAnder71 Thank you so I didn't have to say it.

[@shriharir6450]

@@josephpayne113 so what to use instead of it's?!

[@josephpayne113]

@@shriharir6450 Its.

[@shriharir6450]

@@josephpayne113 ahh.. Ohh well.. Hmm.. Okay!! Well I thought (it's=its).. Anyways.. Tnx tho.. :)

[@robertwilke1208]

I'm really impressed how you were able to drag this out to a 10 minute video.

[@FrostNightVideoProductions]

Blame youtube for pressuring content creators to hit that mark. These videos are free to you, so why complain that they hit the 10 minute mark for ad revenue for the creator?

[@AJAY71731]

@@FrostNightVideoProductions he didnt complain? He said he was impressed lol

[@kwando472]

@@FrostNightVideoProductions Its free yes, but freedom also brings alot of bullshit.

[@superplink]

@@FrostNightVideoProductions I think he was making a pun, but idk

[@ahmadjohardien3993]

How would this be affected by using solid state batteries instead of lithium ion batteries

[@pastresmalin34]

Umm.. in a very real sense, all batteries are solid state. Or, was your comment just meant to be humorous?

[@alexluke84]

1:04 in Slovenia...Toplarna Moste

[@NizaSiwale]

I believe hydrogen fuel cells would work for the aviation industry not lithium batteries. Compressed hydrogen has an energy density of 142 MJ/kg. Lithium ion batteries have an energy density of 0.6 MJ/kg. Looking forward to your next video

[@philipstavrev4856]

I agree with you

[@muddasmasher3045]

Niza Siwale that would be a much more mass efficient fuel source and would be much easier to implement the infrastructure to support, as most forklifts at the airports already operate on hydrogen fuel cells

[@muddasmasher3045]

Jawad H no, hydrogen bombs operate on a combination of fission and fusion to cause a very powerful release of energy. Hydrogen fuel cells operate by electrolysis (combing hydrogen and oxygen to create energy and water

[@JuanAndresLanza]

Hydrogen is dangerous, specially for flying, if not ask the Hindenburg....

[@AngelLestat2]

you dont even need fuel cells, you can use turbines with liquid hydrogen, the efficiency of the turbine increase because you may have higher temperature difference and use lighter materials that would be cooled by the lh2. On fuel cells you can also use super conductor electric motors cooled by the lh2. Liquid h2 is so light that you will need way less fuel to do the same trip, so the volume density is not an issue, even less if you design the aircraft with hydrogen in mind.

[@Flyguy779]

i don't quite appreciate the part about the rockets in the beginning, since even if batteries had the same power density as fuel, since rockets are mostly fuel in weight , there is the problem that batteries don't loose their weight when depleting, not to mention the issue about creating an engine that can put out enough thrust. thumbs up for the for the rest of the video tho ;)

[@Person01234]

But rockets don't require fossil fuels anyway. It's not like we don't have an alternative, it's just a choice the designers of the falcon 9 made to have it use kerosene. The perfectly clean alternative of liquid hydrogen exists.

[@Flyguy779]

that because Kerosene is works better for low earth orbit rockets, also it's denser than liquid hydrogen (which is also why the saturn V had a kerosene first stage and hydrogen in it's upper stages) but for their new Big Falcon Rocket which is meant for interplanetary missions, spaceX will be using methane rocket engines, cuz it can be produced artifically from Co2 and water, which means, it could be made on mars for example

[@Person01234]

I didn't say there was no reason for them making that decision, simply that they did. Ultimately, it's the cheapest, best fit. What I am saying is that rockets, specifically, already have a viable clean fuel option. It costs more because of all the complex systems involved but it's not like an entirely electric rocket would be superior in cost and all around performance to kerosene either, the point is that it would be clean but that already exists. Of course, electrical propulsion systems already exist for spacecraft but right now they don't produce remotely enough thrust to launch.

[@djinn666]

Person Oisels - What you said about rockets is true for planes too. We can synthesize kerosene and burn them in planes, it's just prohibitively expensive.

[@Person01234]

+Q0ET9U I didn't say anything abot synthesizing kerosene. Also many rockets have used liquid hydrogen, it's not "prohibitively expensive" (mostly because rockets are expensive anyway), just more expensive.

[@madmax2069]

Why yes, yes they are. Solar impulse showed that it is possible, and they even live streamed it. But for passenger planes probably not as the tech just isn't there yet.

[@avada0]

8:46 Bio-fuel! (Maybe synthetic fuel, but not to hopeful about that.) In the form of butane, and some cutting-edge fuel cells to power electric distributed propfans.

[@wilowhisp]

I liked having the equations in the video. I watched with a lot of pausing, thinking, and rewatching but I valued the info. Besides even if you just mindlessly drooled through the math the video still makes perfect sense.

[@edwardguo5526]

Great video! How does power required for lift compare to the power required to overcome drag? It would be great if you had included reference so I can do more research on my own. Thx!

[@dankujaneck7376]

I had a question about Flift=Fdrag (5:05) but after reading your comment I think the video creator must have meant Plift=Pdrag. Your comment put me on the right track.

[@ironmantrains]

A few smaller private planes use diesel-electric propulsion as they fly at altitudes low enough that the fuel is not going to freeze. Another way to reduce demand for electric aircraft is modal shift away from air on routes where high-speed rail is competitive, affordable and accessible. HS2 is going to kill flybe, so maybe modal shift is needed so that aircraft companies can shift their focus onto decarbonising long-haul aircraft.

[@TLTeo]

This was some spherical chicken level approximation. As a physicist, I am so very, very proud of you.

[@AndersonChan]

My brain is broken

[@111danish111]

Not to worry all he is saying is that you will not see an electric airliner for another 15 to 20 years.

[@111danish111]

You will see a lot of cool stuff in your life . I am middle aged so not so much for me !!

[@LightPink]

1:53 97.1% of us are males

[@erikhabberstad5633]

I noticed, wtf

[@FrancescoDiMauro]

what a shocker...

[@fokjohnpainkiller]

Who would've expected women to not be interested in useful things!

[@DidntKnowWhatToPut1]

Bit depressing, isn't it? Each to their own, but we've clearly got a long way to go as a society. There's an awful lot of wasted potential being untapped.

[@theyremykidstoo1642]

I don't mind women being or not being interested in engineering, but people claiming we're the same are just wrong, clearly women have other interests.

[@Condurafly]

@Real Engineering: What about "Electric Planes" based on a fuel cell? Probably bit off topic here, but an update on hybrid/hydrogen powered airplanes would be super nice! Also given the limitation of the conversion rate of a fuel cell to convert hydrogen back to electricity.

[@KeppyKep]

Another thing you didn't mention is that fuel is burned throughout the flight, reducing the weight. All aircraft with more than ~8 seats have a higher Maximum Take-Off Weight (MTOW) than Maximum Landing Weight (MLW). This is a structural limit and is because the landing gear has to be able to absorb hard landings, with much more force applied per unit of weight than on taxi and take-off. Airliners always take off way above their MLW because they'll burn enough fuel to be below MLW by the time they land. With batteries, energy is consumed, but mass does not change. So even in a situation where batteries developed to the point of having equal energy density to Jet-A, it's still an issue and there'd be a significant reduction in payload capacity.