Centrifugal Flow - Turbine Engines: A Closer Look

We take a quick walkaround inspection of a first generation Jet engine from the 1940's: a centrifugal compressor makes this Rolls Royce Nene much shorter than the engines developed later, which all used the more familiar, axial flow type of compressor.
Almost all turbofan and turbojet engines today use axial flow compressors.
This engine was used in the Canadair T-33 trainer and a few Australian-built DeHavilland Vampire fighters. A Russian copy of this engine was used to power the Mig 15.

[@grasshoppers7742]

At 16 years old in 1982 I started as an Apprentice at Rolls Royce in Coventry. Had to a day at College once a week and in the class room was one of these engines. One of first lessons was about Sir Frank's original design of centrifugal comps. We all learnt a lot from striping and rebuilding the Nene. Great memories.

[@HighVoltageMadness]

I once saw an amazing cutaway of one of these engines in a aviation museum. Very interesting

[@KeithArnotBurr]

I actually had my hands on one of those bad boys yesterday at the Jet Aircraft Museum in London Ontario. That's what powers the CT-33 and they have a few of them. Very unique design. The guy that works at the museum was asking me trivia questions and he was rather impressed on how quickly I could answer them. Mostly in part because I watch your channel. Thanks for putting together entertaining and informative videos on KZbin.

[@botimegaming]

Thanks for sharing.

[@dumbvixen3776]

Omg bo lol didnt expect to see you comment here

[@RiSuJiCh]

Thank you so much. I always wonder what the centrifugal compressor and the can combustor look like. You cleared all my confusion about the many pages of reading materials trying to explain these.

[@rolandbaranov3546]

It is amazing how much we have improve in no that long of a time; I can see hundreds of engineers drawing and working long hours to develop this engine, many of the features are still in use today. It is always good to look back and see where are we coming from. Thanks for the videos and for the suggested books (bought them all)

[@thomasburke7995]

A direct descendent of Sir frank whittle design... THANKS FOR THE VIDEO..just awsome... hint hint.. tape or saftey wire a small or open cell foam or half a cotton ball over the mic... cuts out 90% OF the wind..

[@deSloleye]

Fantastic to see one of these engines near your shop, will be better to see it in a few bits, seeing the impeller. Had no idea they drew air in from the back of the impeller as well, great to find these things out. Thanks!

[@Finwingman]

I love to see these old engines maintained in somewhat decent condition. I read an old DeHavilland Vapire engine service manual in last month when i found it in my school. There were also some old photos of that engine regarding mantenance. Thanks!

[@jakobole]

Thanks for this - I finally understood this type of engine

[@FrontSideBus]

These are awesome engines, I hope it gets to run! They make bloody awesome noises when running up and at full power!

[@AgentJayZ]

Yes, exactly. There is a certain diameter and airflow capacity which is the threshold, below which the centrifugal compressor is more efficient and cost effective... and above which the best choice is an axial compressor.

[@slicktires2011]

Does the same thinking applies to turbines? Why is it that we sometimes see centrifugal compressors, but never centrifugal turbines? As opposed to a automotive turbocharger, where turbines are always centrifugal and never axial.

[@lloydevans2900]

@@slicktires2011 There is another application where centrifugal turbines are the exclusive choice: Rocket engine fuel pumps, even for the earliest liquid-fuelled rockets. Take the German V2 missile powered by the A4 rocket engine as an example: This had a small catalytic chamber for decomposing high strength (between 80% and 90% concentration) hydrogen peroxide, which generated a hot, high pressure mixture of steam and oxygen. This was fed to a single stage centrifugal turbine, which drove a pair of single stage centrifugal pumps, which delivered the fuel and oxidiser (alcohol and liquid oxygen) to the engine - this assembly is collectively referred to as the turbopump. The gigantic F1 engines on the first stage of the Saturn V rocket weren't much different - far bigger of course, and still used turbopumps. The main difference was how the turbopumps were powered: The F1 engine had a "pre-burner" chamber on the side of the engine which would burn some of the fuel and oxidiser in a very fuel-rich mixture, to keep the temperature comfortably below the melting point of the turbine. This acted as the "gas generator", which fed directly into a single stage centrifugal turbine, which again drove a pair of centrifugal pumps for the fuel and oxidiser (rocket grade kerosene and liquid oxygen), delivering these to the engine. Although small compared to the amount of fuel and oxidiser burned by the rocket engine combustion chamber, the amount of fuel used by the turbopumps is not trivial, and neither is the amount of power they consume: On each F1 engine, the turbopumps used power equivalent to a modern Rolls Royce Trent 800 at full throttle. When you consider that all these are doing is pumping liquids, that gives you an idea of the enormous rate at which they deliver fuel and oxidiser to the engines! Liquid fuelled rockets haven't changed enormously since then - most of them still use a similar design of turbopump, though the method of powering it is variable. Check out a video Scott Manley has done on "rocket engine plumbing", which takes you through all the different fuel flow and turbopump power source designs: kzbin.info/www/bejne/aoK7i2WIr7OShdE

[@jdizzy01]

Wow, wish I knew about this channel earlier. We talked about centrifugal engines a bit in my propulsion class, but I didn't really understand it. Thanks!

[@ajb16991]

A beautiful jet engine, and I'm not biased because I live next to the river this jet was named after... Great videos too, very informative. Thank you.

[@lycossurfer8851]

Those screens work as designed very well. There was an article by a Grumman test pilot named Corky Meyer, who wrote for "Flight Journal" magazine that as he tested a nose separation problem on the F-9 Panther the screens probably helped prevent F.O.D. when the nose blew off the jet.

[@StonyRC]

Bloody hell, you have managed to explain in under 3 minutes what I've failed to understand from hours of reading i.e. the difference in compressor airflow between a centrifugal and axial engine! There is no substitute for SEEING the engine and having an expert guide you. What a beautiful engine, and in such wonderful condition.Many thanks Agent JayZ

[@FirstLast-tx3yj]

Centrifugal compesses air and blows it in a 90 degrees angle from the inlet like a car turbo Axial compresses and blows 180 degree from the inlet like a planes turbine A very simple way to make them relevant

[@AgentJayZ]

The Derwent was smaller, but used as a basis for the design of the Nene. This engine makes double the power of a Derwent.

[@mirceadimian4048]

Nice. I have always wondered how these centrifugal type jets ran. Thank you.

[@emreakkoc1711]

Thank you.I love watching your videos.

[@jimmysparks315]

Up until now I have never heard of them (centrifugal) ... thank you sir !!

[@AgentJayZ]

Yes, for some reason I forgot that the TPE331 had a two stage centrifugal compressor. It is an even more popular engine than the PW100 and its derivatives...

[@tvarad]

Checked the Rolls Royce Nene out just a few days ago at the Science Museum in London (amongst so many other historic engines on display there). It's built like a tank compared to modern turbine engines, possibly because of non-availability of high-strength, low-weight alloys at that time(?). Jay, thanks for de-mystifying the workings of turbine engines through your videos.

[@justforever96]

Yes, there are still centrifugal flow jet engines around. They are used in some very small jet engines, such as on commuter planes, because with an engine that small, it's difficult to make the tiny little high-pressure compressor blades! Axial flow is used with powerful engines, because you would need a huge centrifugal impeller to equal a multi-stage axial design. The diameter of the engine would be huge. This isn't a problem with smaller engines. Some "mixed" engines actually use both types.

[@FabricatorFactory]

Cool. Another great assets to help develop my padawan millwrights knowledge. Great job once again.

[@mas465190]

Great video. Always appreciated.

[@user-bu1qv6vo6s]

Wow, such a simple concept when you really think about it.

[@justforever96]

Both types of compressor were already around, it was only a matter of choosing one or the other. Centrifugal types were shorter, while axial types were longer; each has it's benefits. The Germans chose axial, but these lagged behind for a time, because, as the other guy said, designers had more experience in making efficient centrifugal compressors, as this was what they used in most superchargers of the day. Axial engines soon caught up and surpassed centrifugal types in the end.

[@whatshappend7971]

Great video

[@AB-80X]

Just an interesting little note to add to your comment. Remember that, just about all the small engines e.g, T-53, T-55 ect. that uses a single stage centrifugal comp. stage, use it in the last stage, where the air is moved out to the combustion chamber that are placed around the PT. I don't believe that there's any of the common smaller engines using a cetrifugal comp. in the first stage these days. And back on track:-)

[@clockman47]

Thanks again Jay, Sure enjoy all your videos. Your Friend in Adairsville Ga.

[@VisionXray23]

Awsome. That was a big help. Thanks!!!

[@DrMX5]

I love this video. Thanks

[@pedashisa]

thank you for really informative video

[@LOVACKOJINEUBIJA1]

AgentjayZ,hello from Serbia,i dont know for who you working,but you are one awesome guy,i love your videos and i love to relax myself with your videos,you need to work in school man,i want you here in serbia to teach jung people basic things...keep making more videos please!

[@DScottDuncan]

Hi Jay, Great history video... good to see the old stuff preserved. There is a great jet engine video on You Tube featuring a Rolls "Derwent" from circa 1950, being ran on a simple stand, braced against a storage container (Sea can), in a back yard!! It is titled "Jet Engine Backyard, Ep. 1". I think you will enjoy it. Bare with the first half, which is this guy's attempt at building a homemade engine using a turbocharger. You may have seen it already. Let me know what you think! Darren

[@jtveg]

Thanks for sharing. 😉👌🏻

[@castlebravo]

At that time the West had lots of experience already with centrifugal compressors, from the GE turbosuperchargers on many allied aircraft, as well as geared centrifugal superchargers used in most radial engines

[@buckhubach2720]

Centrifugal style compressors sure seem like an easier way of getting the job done

[@AgentJayZ]

Easier to build, but past a certain mass air flow, less efficient.

[@leneanderthalien]

but centrifugal compressor was the best choice at debut from the turbo jets...

[@HerkCC]

Justin Bronzan I don't agree with your opinion over the fact the centrifugal compress design is still very much so relevant in commercial turboprop engine design. The Pratt & Whitney PW100 series is the best example in aviation today. Twin counter rotation impellers have a compression ratio of over 20 to 1 and reduced compressor weight and overall length of the power plant are what has lead it to dominate the market segment. The JT15D is yet another example....not to mention the use of impellers in PT6, Pw500,Pw500 series engines. BTW centrifugal impeller design and manufacturing is one of the most closely guarded secrets in aviatuon.

[@tannin2249]

Justin Bronzan, not really true. Centrifugal engines originated in the UK, not the USA. America got handed complete, working UK models as part of the exchange of technology the allies were quite good at. The British liked centrifugal engines for two reasons. (1) They were simpler, less fragile, and more likely to be ready in time to actually be used before the war was over. (2) They were already very, very good at designing centrifugal compressors because of all their work on superchargers for large piston engines like the Merlin, the Sabre, and the Centuarus. They went with the skill they already had, and the result was that, despite having started development rather late, they got reliable, well-tested jet aircraft into action in the last year of the war. The Germans went for axial flow because it was theoretically the best solution. The unfamiliar and horrendously difficult engineering problems it presented seemed only to encourage them to try harder, and they eventually did manage to make semi-workable jet engines, though nowhere near as reliable as the British ones. Long-term, of course, axial flow was the way to go for most large engines - but not all, as Phillip Saunders points out above.

[@SuperInline6]

Awesome!

[@colinthomasson3948]

Beautiful engineering, jet turbine engine engineering design elegance par excellence

[@AgentJayZ]

This arrangement is not "common", in that it is in one particular engine series I know of... but it is "common", because there are many exemples of the PW 100, 110, 115,120, and 150 turboprops flying right now

[@MrPinchegabacho]

What a treasure!

[@brabhamfreaman166]

From Nottingham, UK (a mere stone's...maybe a ballistic missile's hop from this baby's birthplace) A beautiful, ingenious piece of engineering history. Thanks AgentJayZ (if that IS your real name, which it may well be) for sharing this and for everything else you do. Can I infer that you don't think the outer mesh lining covering of the compressor intake is really necessary or just overkill?

[@AgentJayZ]

History and experience have shown that inlet screens are not necessary on jet engines as long as reasonable caution is used and the runway is kept clean.

[@MrShobar]

P&W built the Nene under license as the J-42.

[@genericfakename8197]

The Soviets didn't bother with a licence with their VK-1 lol

[@djmips]

@@genericfakename8197 but then China licensed the VK-1 as the WP-5... It really got around.

[@navneet349]

Hey Jay, could you do a video on an engine with two centrifugal compressors that are in a compound setup (if you work on them)? I think they're common in turboprop engines. Also, could you recommend any books that would help me understand such a set up better (dimensions of the compressors for optimal performance etc)? Thanks for your expertise, really enjoy watching your videos.

[@AB-80X]

Is this going back in a plane or is it in any way desireble to use as a gas generator? That was a lot of fun to see. I've read about it and seen a few pics, but never seen one up close like this. Very cool, hope to see more of the insides of this thing and a test run would be sweet. Thanks Jay.

[@Phenomental1ty]

Could I expect to see this in action sometime this month on your channel?

[@micstonemic696stone]

thank you I learnt something about this duel impellor taking air either side was the RR Nene the one copied by the Soviet's for the MiG 15 from the game of Billiard's that was a mistake

[@mytmousemalibu]

Neat! Prolly lots more "eye candy" in the other various containers around there! Nice to see new and differant engines at S&S. Is this a parts puppy or future runner? Showpiece?

[@rapsod1911]

Are there more videos of this engine? I really would like to see impeller.

[@ShuRugal]

That diffuser looks to me like it could feed a second set of combusters and a second turbine? It looks like there is a mounting pad with blanked-off air passageways at 90 degrees to the currently installed combuster inlets? Or is that to allow the 'elbows' feeding from the diffuser to the combusters to be mounted the other direction for an impeller which turns the other way? Anyway, very neat to see a different style of engine.

[@DanDeZinna33]

Beautiful engine! What are your plans going to be with this engine jay!?

[@AgentJayZ]

It has few options: It might power a private T-33, a training version of the P-80, built in Canada... of it could make a very interesting jet truck / car ... As far as I know there is not an industrial application of this engine.

[@0sheldm]

in the mig 15 there is that distinctive intake that splits the airflow, does one half go the the front of the compressor, and the other half goes to the back of the compressor?

[@555RavenCrow]

It just goes around the cockpit and merges back in front of the engine.

[@TheRantingCabbie]

Saw one of these at the Niagara Aerospace museum. I'm pretty sure it was also a Rolls Royce.

[@supersavage123]

hi great video, is this turbine similar to a rr derwent-(spelling) awesome engine

[@htweiss256]

Jay, I love your videos... I've seen this engine in cut away at my university. To share, There is a Indian University (Yes in India) that has posted over 100 courses on KZbin. For your viewers who are interested two of the 40 hour courses deal with jet engines and their design. They are "Aerospace - Turbomachinery Aerodynamics" and "Aerospace - Jet Aircraft Propusion" at NPTEL. They are in english and hard core. Thanks again for your wonderful videos

[@izysly6924]

It would have been neat to see that engine start up and run

[@AgentJayZ]

It would. Still waiting for someone who needs it.

[@AgentJayZ]

This is done with a few aircraft engines, and many industrial compressors. Only each successive compressor is different than the one that precedes it. They are usually smaller and of different shape. To do exactly what you have described will not work very well.

[@turbodyne.lighting]

"piece of history" is very true, is this a customer engine to be refurbished and ran?

[@AgentJayZ]

You're talking about the P&W PT7, which was renamed mid-development as the PW100 series.... It's one of the engines that made me say "almost" in my description. Dimensions for optimal performance? If you want specific numbers, you're going to have to get a job with P&W. We never see these engines, but maybe someday... A lot of information is available, but not easily, and sometimes not for free. If you dig, you will find sources.

[@Fierobsessed]

My Marbore II has a single sided centrifugal, a 15" diameter impeller, It does have an axial turbine, I think the engine is pretty cool. I've always wanted a classic axial compressor engine, so much more power given the size. At least the centrifugals are stubby, perfect for the back of a car... Hmmm....

[@Ropponmatsu2]

In short - because of the fact that the British developed their jet engine designs from scaled up piston engine superchargers: Just big versions of today's car turbochargers. Frank Whittle used a scaled up version of the centrifugal blower used upon engines such as the Merlin and the Vulture. Also, remember that Whittle had to deal with real opposition in the RAF, who didn't see the point of his work. He didn't have much money and so started with what he had to hand.

[@martinwarne7183]

No. Try reading "Not much of an engineer" by Sir Stanley Hooker. He was the person who improved the supercharger for the Merlin, and worked along side Sir Frank Whittle on the jet turbine. Once read you will see how not so clear cut your passage is. With all due respect to you.

[@anthonygiacomelli505]

When do you plan on firing it up and if so would you let us all know.

[@adityang5128]

Sir which one is efficient for small jets ....the centrifugal one or axial one??

[@AgentJayZ]

This is similar, but I think it was developed after the Derwent.

[@justforever96]

Just the guy I was looking for. I have a question: how is it that you can get away with having a single centrifugal stage, but need several axial stages to get the same compression? Is it something inherent in the compressor type, or just because one centrifugal impeller is much larger and has more "blades" than a typical axial stage? Seems odd that one centrifugal stage can compress the air as much as several axial stages, but it must. I assume it's a function of the diameter of the impeller.

[@dumbvixen3776]

Im a bit confused but if the engine does not have that great of a air intake like a new engine in the cold war ish era "j57" does the air build up and cause problems? Because the russians took the engine and remade it into the klimov vk1 engine and was used in the mig 15/17 jets and the nose had a pretty big intake but as you showed in the video the amount of air that can get into the engine at a time is very limited. Does it build pressure on the airframe? And also does it result in compressor stalls?

[@AgentJayZ]

You really need to read a bit on the history and development of jet engines. You will enjoy it, and all of your questions will be answered, or shown to be unnecessary. The first chapter of most of the books I recommend in my video called "Books!" will satisfy your curiosity.

[@Coolkeys2009]

Hope you can put that on the test stand if it's safe.

[@ChrisMuncy]

Jay, What are the plans for this engine? Rebuild for a customer?

[@ThexPRESIDENTxVIDS]

Can you do more vids on the turkey feathers?

[@emreakkoc1711]

1-)If I put 2 exactly same centrifugal compressor as a multistage compressor.will second centrifugal compressor compress air again. 2-)What happens if I put 5 exactly same axial compressor without changing housing diameter will air be compressed more than one axial compressor .thank you

[@VladAndreis]

What would it take to get this engine fired up in your test cell?? I would be livid to see it brought back to life!!

[@tammyduong1688]

But how did it help the flying bedstead lift an thrust

[@jim5870]

You could make a really neat "Road Warrior" vehicle! ........

[@crazyoldhippieguy]

Do they still use ecentafuge impeler on air planes?, these are dinasures ?And on what.

[@VisionXray23]

I know that modern jet terbine blades are made out of titanium. What are the blades on these made of ?

[@pyrexian26]

nice i think i got first view of this video! beautiful engine though.

[@AgentJayZ]

I think you might be interested in a video I made about that subject. It's called Ebay blades.

[@janakmedicos9735]

Jet engine.

[@Spudforth]

I understand that your start cart has a tiny Centrifugal engine in it? This engine was popular in the 40s because it was much less likely to have compressor stall than the early axial flow models?

[@AgentJayZ]

Jeff Manning Garrett did not make any axial flow APUs or small engines. The two types of compressors are best suited for a different range of sizes.

[@CrazyForCooCooPuffs]

+AgentJayZ Garrett TPE331 Jay

[@AgentJayZ]

CrazyForCooCooPuffs What about it. It5's a highly successful small gas turbine engine with a centrifugal compressor. What's your point?

[@CrazyForCooCooPuffs]

AgentJayZ nvm I misread your post.

[@lance_the_avocado9492]

I’ve never really understood centrifugal turbojet engines. More and more I think about is that it’s just a Turbocharger with fuel injectors, manifolds, and a turbine that’s designed to create thrust!

[@AgentJayZ]

Turbines do not create thrust. A turbine takes energy from a moving fluid stream and converts it into mechanical torque on a shaft. Real world fact check: a wind turbine does exactly the same thing.

[@lance_the_avocado9492]

@@AgentJayZ Well yes but these turbojet engines do make thrust correct? Burns air fuel mixture, air fuel mixture gets sent to the turbine where it spins the turbine, the turbine shares the same common shaft as the impellers which compress the air, send it to the chambers, fuel is injected into the air stream creating the said mixture where it ignites, and is sent to the turbine as the turbine speed increase, so does the impeller speed, creating more dense air, requiring more fuel, resulting in more powerful combustion and In turn spinning the turbine creating thrust due to the exiting of the hot exhaust gasses. Unless I’m missing something there I’m pretty sure that’s how the centrifugal turbojet engine works (very simply put) where as the axial flow turbojet ensures that the air entering the system is also leaving the system in a nearly straight order instead of having to bend highly dense air through different angled manifolds and inlets.

[@AgentJayZ]

Yes, a turbojet makes thrust. Maybe you got me confused by saying a turbine makes thrust. One of the most common mistakes the general public makes is to call a turbine engine a turbine. Those are not the same thing, and it matters.

[@lance_the_avocado9492]

@@AgentJayZ It’s all a little confusing but I just kinda assume engines as an air pump, yes a very basic and frankly amateur way of looking at it but that’s what it effectively is. It utilizes air in a system to create some form of power, torque, horsepower, and thrust (and many others) but the turbine technically helps push the hot air/exhaust (that is expanding) out of the system which results in thrust or forward movement from the moment the exhaust gases leaves the turbine. However I feel the design of a general turbine is designed to create thrust itself. Creating low pressure on one side of the blades while increasing pressure on the other, the turbine fighting the high pressure air or fluid on the other side resulting in thrust or movement. It’s a way of understanding Newton’s third law in theory, however simple you make it, the same concept runs through it all. Again I could be missing all of this though so please don’t waste your time on lowly little me!

[@torukmacto4879]

Sehr schönes Teil. Lief wo?

[@leneanderthalien]

das RR Nene triebwerk wahr auf sehr viele flugzeuge (serie oder experimental flugzeuge wie die So 6000 Triton) benutzt,meistenz auf DeHavilland Vampire und Dassault Ouragan, und auch auf... Mig 15 (wurde under lizenz in UDSSR gebaut)

[@billyost1479]

Did you buy that or is it for the museum?

[@AgentJayZ]

It's a fresh overhaul from RR Canada, and it's for sale.

[@AgentJayZ]

" sorry about the wind"... there was no protection from it.

[@AgentJayZ]

This engine has no afterburner, so no variable nozzle.

[@Kakariko505]

I really wish I could work on Jet Engines :(

[@spartan13014]

Where do you comme from in Canada? Do you speak little bit of french? ^^

[@aldossari2009]

I think (YOU ARE GREAT)

[@JoseGonzalez-ko4rz]

I hope one day I can see them up cloase and personal.your are so lucky . I’m a mechanic for the last 40 years . My dream is to be a air plain mechanic. I know I’m old . But one can dream

[@sotirisathanasakis9804]

Nene 10 , T-33 engine. This engine has to have radioactive parts, is it true ?

[@AgentJayZ]

Some of the magnesium alloy parts have a small amount of thorium in the recipe. Technically that makes them radioactive, just like a glow in the dark watch dial from back in the day.

[@TalksWithDirt]

Oh look! It's the Brittish copy of the Klimov VK-1..... ;P

[@Vicarium]

Man, I can't imagine a afterburner doing much more than make noise on this motor anyway...

[@Phenomental1ty]

derwent can typically be confused for the nene by rolls royce.

[@dsfs17987]

or was it the other way around? :)

[@shaithesm0ck]

the audio is some times dropping

[@Daluke61]

Going to fire it up?

[@chanvibolpenM2_22]

Like

[@TCSC47]

My "I'm almost famous" claim is that my children went to the same school as Frank Whittle.-- (Not at the same time of course.) --Binswood 6th form College in Leamington Spa, which used to be Leamington Boy's College. Cool, eh? It is no longer a school and has now been converted into luxury old peoples retirement homes.

[@rossblake101]

How easy to flood and burn one of these starting by accident? Ever suffer too much or “over rich” fuel mix/supply?

[@AgentJayZ]

Normally, the human does not control the fuel. When fuel flow during startup is controlled by a human, the potential for overtemp damage is increased dramatically.