So You Want to Design a Jet Engine 

I am an professional Aeronautical engineer. Currently i work for Rolls Royce Civil large engines. Believe me designing a whole jet is not a small job, it take 10-15 years of research and thousands of engineers hardwork 🔥

As an engineer, I appreciate your effort to convey just how much knowledge goes into high tech items. I was an engineer at McDonnell Douglas, and later at Caterpillar. I worked with so many smart people in so many different areas of expertise that it was truly humbling. It was a joy to work with so many clever people. Hopefully some of your viewers will go into these areas of study, make contributions, and share their stories.

"So You Want to Design a Jet Engine?" Who doesn't?

My day job is commercial jet engine certification and military engine qualification. I have held Whittle`s engine test logs in my hand. It is rocket science, to be sure. And even with hundreds of engineers and supercomputer fluid dynamics, stuff still doesn't go according to plan. Ever.

I was always impressed by your restraint when questions of this sort showed up. I'm impressed that you were able to prevent this from becoming a bit of rant.

When I was young I thought everything was designed from scratch. Only later did I realize that nothing is designed from scratch. There's always a working unit that serves as the starting point. Great video Agent JZ. Always fun to listen to you

I am an engineer at a small jet engine manufacturer in our expansion department (everything combuster and aft). It can take weeks to just to change the tolerance on an engineering print by .002" because of how many people need to approve of changes. And I work on small engines, I can't imagine what the manufactures of the larger ones have to deal with. Engines are very complicated and it takes teams of people and a lot of time to design new engines. Even if you could design one by yourself, manufacturing one is an entire other story too. Tolerances on the shaft of an engine can approach .0002" and it takes a lot expensive equipment to manufacture parts that accurately. I think its pretty unrealistic for an individual to make a jet engine approaching the complexity of any production engine.

The Avon blade measurement at the end literally broke me 🤣🤣🤣.... I once saw the blueprint of this exact part and i have to say its a really impressive drawing. The curvature have 7-8 different profile with many more spline control point for each one of them......... and all that where created in the 50's without CAD !!! I have a LOT of respect to the engineers and machinist of these time. Good wake up call to those little budding genius !!

As a jet propulsion engineer, this was very amusing. Great job and choices of words, you’re 100% correct. I also own a few books from Mr. Mattingly that were part of my college courses, including the one you mentioned. Great books.

Designing a jet engine - sure, no problem. Building it according to the design - well, let's see. Making it run - uhm, not so sure about that. Preventing it from burning up - ok, _that's_ a challenge. Producing thrust - probably not. Making it run again, and again, and again for hours - yeah, I'd like to see that... Making a plane fly with that engine - I highly doubt it. Getting me on that plane - no way, dude! Oh, btw: Happy new year, to you, @agentjayz! All the best, for work, for making videos, for racing, for repairing speakers, mountain biking and whatever else there might be!

Great work as always 👍 12:30 as a machinist I have had long arguments with engineers and designers about standardisation of parts ,some clown at a computer draws 330 non standard countersunk bolt dimensions and then wonders why the machinist wants to hit him over the head with a book of bolt standards ...🤣👍 (real life example ,not in any way related to building jet engines ,but a real life example of why designers need people checking their work BEFORE it goes to the machine shop...)

I have an idea for an upgrade on the Harrier engine. I will call it the Harriest.

_17 people have their soup cans and tin snips ready to go._ ☝🤓

Well said. This reminds me of several people who have told me that because they flew a helicopter in a computer flight simulator, they could fly a real one. I challenged them to do the by offering to pay for an hour in a 206 without prompting from an instructor... but they had to pay me back double if the real pilot next to them had to touch the controls. They all backed down.

I've waited patiently and it's finally our turn. The runway is ready, the airspace is ready, the throttles advance. the brakes release. I begin a journey of several hours that it might take a man on horseback several weeks to complete. As speed builds, a childish voice behind me says out loud what I always say in my head, "Yee Haw!" Perhaps a future technician or engineer with skills to help transform piles of ore and puddles of petroleum into this fantastic machine. Then I glance down the isle to see folks reading newspapers or listening to MP3 players. Don't they understand the extreme forces and temperatures at work just outside the windows? Sadly, they are missing out, the poor, misguided souls. Thanks for the inspirational New Year rantlet.

I've counted to infinity twice, but I can't imagine counting to infinity squared.

If someone even wanted to begin to design their own jet engine, it would help to 1) have a mechanical engineering PhD, 2) Gather a team of CAD designers 3) Hire a fluid dynamics PhD 4) Hire an Electrical engineer and 5) Buy a $5 million dollar user license for CATIA and time in a NASA-like testing facility. However, design concept/type modifications as suggestions are just fine. Nobody gets harmed from the suggestion of a concept. They can either accept or reject it and then move on, easy peazy.

After 4 years of study at Embry Riddle Aeronautical University - Aerospace Engineering (Propulsion) - your senior (5th) year project is to do just that, design a turbo jet that functions on PAPER. It takes 5 of us 5 months to get that far with $1M worth of engineering software. And we don't even know if it will work in reality. Food for thought.....(5yrs at Riddle $250k)

I spent my career in an Aerospace Foundry. Many of the parts in this series are from the industry and even the foundry I engineered for. The material science and metallurgy is supremely advanced. Alloys in jet engine construction are Titanium in the cold section and superalloys in the hot section. All of those alloys have to be cast in advanced vacuum induction and arc reduction furnaces. Those processes are completely beyond any home hobby project. You might make a small jet but it will not last and will be nothing but a hobby simulator.

after 15 years of fiddling around with our self build rc jetengines, we are thinking of designing a bigger one. (mainly because the neighbors unimpressedness of the noise.) Now you scratch on my confidence a bit... But on the other hand, we do not expect to be better than anyone, it only needs to scare my self. I will read some more books and decide later... Happy new Year and thanks for the content and booktips and all

I was privileged to be introduced to, and shake hands with, Hans Von Ohain during a short meet and greet ahead of a class that I was taking in the late 1980's. Really enjoyed his presentation.

"The dimension of the compressor is.......42" 🤣 ahh jee thanks mister that's the number I was missing lmao Great vid

“The more you know, the more you know you don't know.” ~Aristotle

I'm building a tokamak fusion reactor for my high-school science fair project, can you provide any pointers?

I only needed two books to design my engine. "Gas Tubine Theory 4th Edition" by Cohen, Rogers, and Saravanamutto and "Gas Turbine Combustion" by Lefebvre. These are not introductory books and assume you know thermodynamics and have an engineering mindset. But everything is covered. Mine is a 300mm inlet engine. So APU scales, but will be using a free power turbine output. My advice to beginners is to make a automotive turbo engine first. It's been done a million times, yea, but the theory and design is only half of it. Combustor design is generations tribal knowledge and not methodically engineered as the compressor or turbine. Automotive turbo gas turbines use can style combustors which are easy to iterate on. Get good at that first, then go bigger and more expensive. Why blow more money on R&D than you have to?

I’m going to design a warp drive

I Saw a Russian youtuber build a model jet engine in a shed, most impressive show of solo craftsmanship and engineering I've ever seen

Every video my wife ask "why do you watch this channel?" I'm not sure why but I like him

With regards to measuring the length of a crankshaft, one time in my shop we received a compressor rotor from our customer's spares line and they asked us to prep it and install it in an overhaul we were doing for them. We visually inspected it, cleaned it, inspected it again as normal, Checked balance on it, and began the installation expecting zero problems. As we lowered the unit down towards the case it became apparent that it would never go in as the stages were not in their correct positions. After a ton of head-scratching followed by a very vigorous teardown inspection, we discovered "shop-X" had lapped the living daylights out of the compressor discs (TB5000) shortening the compressor rotor assembly by over .750 inches. Total scrap.

The standard answer is: if you have to ask for a solution in a youtube comment, it is clear you haven't done even your most basic preparation on a topic.

You have put more effort into this presentation than most of the wouuld-be designers have put into their projects to date.

Again... your Burke/Asimov level of explanation and wit is on full display. I also break down technical details so people without the knowledge can digest them without their heads exploding. Well done.

I heard Dr. Hans Von Ohain speak in person about developing the jet engine. Lots of work and required the facilities of hieklel to get an actual working engine. Dr. Von Ohian started with crude proof of concepts to show that it might be able to be built at first. one of his biggest problems early on was getting liquid fuel to burn, he developed his very first engines using natural gas as a fuel. Dr. Von Ohain was a great guy. I am grateful that I had the honor of hearing him speak .

Happy New Year, thanks for all the videos this year, you’ve helped keep me sane. 🙂👍🏻

One of my first summer jobs was working in a spin-pit, balancing radial flow components for APUs. A ton of money invested for one small aspect of many. I encourage all jet engine developers to video their progress and tests... RUD (Rapid Unscheduled Disassembly) videos get a lot of hits on RU-vid. AgentJayZ - thanks for taking the time to prepare and post these videos, love the tech talks and history you bring. A dram is 1/16 of an oz. or about 1.77 grams. Happy New Year all!

Came for a rant and wasn't disappointed, great start to the new year! Gave out the compressor dimension.... of a turbine blade. I know you were testing to see who was paying attention.

I am en electronics design engineer. I have also designed some mechanical systems for commercial jets. For a laugh I decided to try and make a "bean can" jet engine. The best I managed was 0.6ish pounds of thrust for somewhere between 25 and 27 seconds before it destroyed itself. That's with mad maths skills and a good knowledge of design processes (though not the specifics of turbojets). To mnake things easier it used propane and brass ring burner with v shaped steel flame holder (bent in a circle which was a complete game). Colin Furze managed to make some better engines but they need way more in terms of oil pumps and all sorts. Even then he maxes out at 100 pounds thrust or so and it guzzles fuel like a mad thing (as did mine). I worked out that mine had about 1% of the efficiency of a Williams FJ44. So though you "can" get something that sort of works, JZ is absolute,y correct in that it takes a large specialist team ages to get an engine right. I live near the RR plant and know some of the engineers, and one I used to drink with a lot spent two years on one compressor blade to get it to the point where RR were happy with the performance. That's two years for a guy to get just one of several blade types right. Apparently the turbine blades are a lot more difficult.

Turbine design is basically rocket science :D There's a reason why top turbine engineers were hired at the beginning of the space race to help design new rocket engines that would take humans into space. The key to rocket engines at the time was new turbo/tubine pumps.

As one of those people who are undertaking this kind of endeavor, reading the books Jay presented and getting intimately familiar with a 3D printer should be your first steps, followed shortly after by forgetting everything you know about internal combustion engines and how they may benefit your wild design, because almost nothing short of metal fatigue and the general principles of combustion will transfer. I'm 2 years into my process, have 3 massive redesigns under my belt, an entire workshop of parts surrounding me, and a giant hole where my bank account used to be. After finally finding a breakthrough that perhaps could/should make an evolutionary breakthrough of the next generation of engines that can be made for multiple platforms, I will tell you that packaging and new materials are almost certainly the two most obvious areas where one can find the most benefit to 'reinventing' the wheel, provided you can scale it both up and down. Also be prepared to fail and fail often, learn from your mistakes and improve from your failures. I hope to have my failures on display when I finally get this prototype ready to unveil to the world that should make an interesting museum entryway exhibit. Your processes you develop will also have more impact and possibly benefit your bottom line far more than the end product itself, so get ready to learn about protecting trade secrets along with becoming an engineer, machinist, chemist and any number of other specialists. Lastly, be prepared for everyone in your life to call you a whackjob and expect constant ridicule. =/

Yeah, my experience in product design and manufacturing taught me that everything works perfect in concept, in principal and will sell fantastic. In reality the devil is in the details. That's when you learn that nature is under no obligation to follow your speculation and the customer is under no obligation to be impressed by your hard work. Nature will do its best to see you fail and you have a mountain of odds to overcome.

31:00 - 31:50 ... literally the hardest I’ve laughed in the past year.

Happy New Year, J !

I think people confuse being able to work on something vs knowing how to design it. The amount of time spent on the design of a part let alone a section of an engine is massive. A jet engine mass produced is a 10-30m asset. That should reflect the complexity involved in design. A piston engine is literally 1000 times simpler.

Excellent video! I wish each content creator made a video like this about their respective field. Happy new year!

Happy new year, love your videos.

I love this video, even more the "dimension" part !!

Happy new Year, thank you for all your videos, one of the best channels on You Tube!

I don't think too many people will understand where the answer of 42 came from! It will take awhile for the computer to come up with that number and you will have to remember what it was that you were trying to calculate in the first place.

So, I can start with the layout. 👍😊 Happy new year!

You are referring to the 'Dunning- Kreuger effect' often btw.

The more you learn the less you know.

I didn't want to build my own jet engine. Now I kinda want to build my own jet engine.

Ok, ok I get it. So a rocket engine it is.

I mounted a bottle rocket on a balsa wood airplane. It actually flew, until the wings fell off.

42, the new golden number :-) ;-) I love your channel. Geeting from France

Love the Man or Astroman shout out! I've been listening to them for so long. Something about their album art appeals to me as an engineer. :-)

Happy new year!

the amount of facetiousness in this video is just right! you're awesome!

You come up with some of the best content. It's almost got me inspired enough to see if I can engineer a solution that would use something like a RB-211 to heat up my day-old pizza. Eat your heart out, Rube Goldberg.

"42" "Inches or millimeters" "Yes"

All the best for 2021 ----A Dram inch, it is well explained below, my preference would be a "wee dram" I imagine a few of those went down well last night, and not only in Scotland.

Thanks! Professor!

In my study program as a mechanical engineer there are two subjects that in total are worth 25 credits ... 1 credits are worth 25 hours between lessons, exercises and average personal study ... they make a total of 525 hours of study on average ... these two subjects serve only to carry out the objectives of the first step of the development of a jet engine. I say this to point out that to make any engine there is a lot to know and a lot to study and I think that those who want to design a jet engine by themselves have certainly not made suitable studies, otherwise they would never have come here to ask the questions I heard in this video.

Thank you!!

Watching the broaching machines at P&WA E. Hartford was amazing. A large machine that was incredibly quiet. Cut the fir trees in the turbine disks. I think they are now machined on a multi axis CNC machine.

Man-or-Astroman?! A great band! I had the opportunity to see them at the Horseshoe Tavern in Toronto years back, they referred to themselves as 'a poor man's Shadowy Men' with much praise given to that band, they even covered a shadowy men song, with members of that band in the audience as well.. they had Tesla coils on stage, the whole bit.. was super awesome. The methodology and passion with which you approach your stuff is similar to the way I approach the maintenance of restored and very old large CNC routers.. lots of facts, stories, wisdom, and it's fun.. thanks for sharing this stuff!

I found a copy of EEVIAC at the library prior to the widespread adoption of high speed internet and didn't understand what the title was referencing until i asked my grandfather, who somehow knew things about the ENIAC. Dredging up childhood memories here.

hope you have a happy new year :)

I am not sure if I was supposed to laugh my ass off or not, but I surely enjoyed this one. I am only a semi-serious enthusiast with gas turbines, which I continue to look upon with wonder. Cutaway drawings are the tip of a very beautiful iceberg here. When you get to computational fluid dynamics and supers, you really appreciate how much you must rely on experimentation and upon trial and error in this endeavor, which really says, we don't really know all of what is going on, so we tell stories and fabricate parts so we can find out how the story ends. Love your channel.

I love this video. I feel your pain on this topic in my own field (electronics), and also lately in discussing politics... "Just a little hand-waving and a good marketing slogan, and we can change the world..." Yeah, it doesn't work like that. Better to spend that money and effort somewhere else, but convincing people of that is a challenge I no longer accept.

this video would easily apply to me when I was younger. I actually submitted my MS paint drawings to the Canadian air-force.. I still cringe about it now-a-days.. but hey, I've learned from that, and continue to learn, so that's progress I guess.

Wearing a wooly hat and in short sleeves. I like Canadians. Thank you for your videos which I discovered yesterday. I have only ever been a passenger sitting between two or four jet engines, and only now I know how much I didn't know about them.

Love this vid and is a great pointer of the reality of the engineering world. I work in mechatronics/robotics and even the smallest of tiny minor decisions is made by and gets input from multiple brains. Look up the dunning kruger effect aka the realization of most things are never as simple as it might seam.

First AvE and now AgentJayZ what is it with me and slightly mad Canadian sheds in workshops.

Happy New Year! You ain't kidding! There is REALLY no way to revolutionize this multitude of design! It maybe can be improved in some unforseen way but I just can't see that the industry hasn't looked at it before. Then again I'm pretty ignorant to so many details and am not affraid to say it! :)

You're such a smart aleck, I love it! I'm also interested in designing my own jet engine. My my goals are not quite as lofty. Something fairly small that can fly and won't get me blown up. I still feel like that's a reach, though. I'm interested in doing so for the learning experience, not for the end product.

Happy new year 👏👏👏👏👏👏👍

Say it as it is mate - very entertaining to a fellow engineer 👍😂 Especially the advice on how to locate books.

you can't design a gas turbine, but you can design a pulse jet or a solid fuel rocket (if you are smart.) Those are technically jets.

This dude learnt the hard way

Came for the engine lessons Stayed for the ranting

I agree with assertion one shouldn't check something off a list until it's done. Checklists can help keep you from screwing up and forgetting something. But it won't do its job if you screw up the checklist by not using it properly. Geez, I sound like my dad. 🤣🤣🤣

I was working with turbojets and turboshafts. My ambition was to design my own jet engine form scratch. Considering available resources I could fund model jet engine size development. So I took a challenge, as designer, machinist, technologist. It takes 9 years working part time in hobby project, building three prototypes - 1st was forced to work by extreme EGT, 2nd - work well at idle conditions, 3rd - work as expected good acceleration, low temperatures, reliable. Only compressor wheel was took from turbocharger, diffuser,combustor, axial turbine was my design. Designing small turbines you would be limited by available bearings, and available of round bar of Inconell.

I recommend Sir Stanley Hooker's excellent autobiography. Not much of an Engineer. From the Sptifire supercharger to the Whittle engine to the RB211. Its quite a tale!

Now this is the teacher I want in my schoo

lol, 1st time watching you. luv it!!! super smart and witty. I can tell annoyed and all/ all of us are with covid going. chin up and happy new yrs :)

Mechanics like this give piece of mind to the statement flying is the safest means of transport

Hello sir , Possesing the knowledge and experiences like what you have now .. already conquering the world .. hope one day i can learn from you .

most badass presentation possible of all time. all of mankind could learn much from this if they listen to what you say and not the words that are spoken! agent jz for village witchdoctor!

I think you're understating the difficulties involved.

Thanks...!

I have a copy of Mattingly's book. Can confirm. Lots of math. People get PhDs in individual sub-disciplines related to processes that occur inside these feats of engineering. I even took a swing at trying to get a self-sustaining engine running using food cans as the primary building material. The engine never worked. But it was certainly not a waste of time: I learned a lot.

Virtually no-one gets the opportunity to design an engine today nor have they done it for many years.

Dunning-Kruger comes to mind.

Another excellent video, thank you. What is the dimension of the dog ?

Ha! Thanks for the (mild) & funny rant. clips. standard modern issue, the internet has helped create the persistence of ignorance , so that majority for people now under estimate the difficulty gaining any hard acquired skill or knowledge. First point to the misguided is if a multi-million dollar company with hundreds of experienced engineers can’t make a better engine= profitable engine ... why do you think you can??!! Someone saying they can “revolutionise jet engines” are just saying they are so dumb they don’t understand the level of complexity involved in designing one. Thanks for sharing your hard earned knowledge 😁. All the best for the new year.

Bringing some hard, and very necessary truths.

There's all this talk about the answer being 42, so I think that we should really challenge the folks who think they can design their own jet engine to come up with ..... The Infinite Improbability Drive.

Literally have everyone of those books and more... one could probably cobble together a 1st generation engine from published data. The vast amount of proprietary data that's actually used to make a real engine is locked up in the big boys design offices. But every year low price CFD software is pushing the boundaries of what can be simulated. I think it's only a matter of time before someone does it.

I hope you’re having a happy new year.