9 ms·

Animated Engines

696 points by marcodiego 6y ago

Judgmentality 6y ago
This is neat. If someone wants a slightly more comedic take on automotive engine designs, Donut Media has some interesting content. https://www.youtube.com/watch?v=8YIDOjD0oBI https://www.youtube.com/watch?v=8YIDOjD0oBI EDIT: Removed erroneous claim.
- capableweb 6y ago
  > Donut Media pioneered the "suck squeeze bang blow" descriptor of the 4 stroke engine Someone please correct me if I'm wrong but I think I've heard the term "suck squeeze bang blow" way before Feb 23, 2021 and also before 2015 (creation of that Youtube channel) so I find that claim hard to believe.
  - bagels 6y ago
    It predates that channel by decades.
  - Judgmentality 6y ago
    Sorry, it's just the first place I'd heard it. I'll edit my comment. I wasn't speaking on behalf of them. Weird. I've been talking to people about cars for decades and I'd never heard it before them. Is it just something that people don't say anymore? https://mechanics.stackexchange.com/questions/28682/who-came-up-with-suck-squeeze-bang-blow https://mechanics.stackexchange.com/questions/28682/who-came... I guess for whatever reason it's just not used as much, or at least not enough that I've heard it before.
  - pen2l 6y ago
    This text dated 1981 mentions it (page viii): https://link.springer.com/content/pdf/bfm%3A978-1-349-06976-7%2F1.pdf https://link.springer.com/content/pdf/bfm%3A978-1-349-06976-... edit: and googling some more, there are instances of in being used it 1950s. And the likely first author of the saying might well be the inventor of the 4 stroke engine himself, Nicolaus Otto, who used a similar saying to describe it: Saugen, Drücken, Knall, Schlag.
    - wizzwizz4 6y ago
      Only source I can find for your last claim is https://mechanics.stackexchange.com/a/28690/33924 https://mechanics.stackexchange.com/a/28690/33924: > Actually, I wouldn't be surprised if the great Nikolaus August Otto, inventor of the four-cycle engine had a similar saying to explain his engine: Saugen, Drücken, Knall, Schlag... So I think this is apocryphal.
      - pen2l 6y ago
        You might be right, I'm not sure. At least in Otto's patent filing (which is found in English here: https://patentimages.storage.googleapis.com/1f/3f/4c/821c6da1070930/US194047.pdf https://patentimages.storage.googleapis.com/1f/3f/4c/821c6da... ) I don't see such an expression. I do see though that the breakdown of the Otto cycle on most sites including German ones (https://de.wikipedia.org/wiki/Ottomotor https://de.wikipedia.org/wiki/Ottomotor) is usually made in a way that just sorts of lends itself to being transformed that way. Well, thanks for making me go through his writings, this was fun!
  - cableclasper 6y ago
    Yeah. I've seen it in an old BBC documentary: The secret life of machines - Internal Combustion Engine https://www.youtube.com/watch?v=gfr3_AwuO9Y https://www.youtube.com/watch?v=gfr3_AwuO9Y
  - NikolaeVarius 6y ago
    Wow screw this channel for such dumb shit.
  - mhh__ 6y ago
    Even top gear referred to it as such probably a decade prior
- berniemadoff69 6y ago
  > If someone wants a slightly more comedic take it seems sort of rare on the Internet, particularly in videos, for someone to NOT be doing a 'comedic' take, along with a jump cut every 5 seconds, background music; all kinds of stuff that feels like it is desperately trying to do everything it can all at once to make someone not hit the back button. ironically, hitting the back button is the first thing i do when a video starts with 'Wats up Guyz' or something along those lines. the original post is a breath of fresh air, straight to the point. I wish the Internet was more like this in general.
  - marcodiego 6y ago
    These "jump cut every 5 seconds" is the reason I've been watching less youtube everyday. It completely breaks continuity and are so frequent that a significant part of the video is wasted. Reading and watching an animation is better than video tutorials in almost every regard.
- spike021 6y ago
  Something to keep in mind: several sources of actual topics have contradicted Donut Media views on certain things and DM has been known to steal video clips without crediting where they got them or use Wikipedia articles as established sources. Not that all their videos have these issues, but some do and it gets pretty ridiculous.
amelius 6y ago
How do you drive the fuel into the highly compressed chamber, in case of the Diesel engine?
- capableweb 6y ago
  The diesel engine is found here for the record: http://animatedengines.com/diesel.html http://animatedengines.com/diesel.html Short answer: you need a fuel injector that can handle injection into the highly-compressed air. Longer answer: https://www.britannica.com/technology/diesel-engine/Fuel-injection-technology https://www.britannica.com/technology/diesel-engine/Fuel-inj...
- jcampbell1 6y ago
  Until very recently, the injector works by a push rod from the cam shaft, meaning it is powered the same way the valves are. In modern engines you have other options such as an electric piezo stack hammer to force the fuel.
  - SigmundA 6y ago
    You might be conflating how an injector turns on and if with how the fuel is pressurized. Unit injectors create the high pressure for injection in the injector, combining the high pressure pump and injector in one, fed by a low pressure rail. Theses are driven mechanically via cams to create pressure. Common high pressure rail injectors have a separate high pressure pump connected to engine elsewhere and the injectors just turn on and off fed by a high pressure common rail. The injector itself can be actuated mechanically or via solenoids or piezo, but there are no injectors that create pressure electrically that I know of (the closest I have seen are voicemail medium pressure gas injectors used in ETEC engines). That is the electric part of the injector only lets the fuel through, it does not force it.
- dugditches 6y ago
  via a 'fuel/injector pump'. Can click through this to get an idea of just how complicated(and analog) they are. https://www.youtube.com/watch?v=DKZL7Y0b5-U https://www.youtube.com/watch?v=DKZL7Y0b5-U
prashnts 6y ago
Quite interesting! Reminds me of http://507movements.com/ http://507movements.com/ Edit: It’s linked in the website as a “sister site”.
- ourcat 6y ago
  I was about to say the exact same thing. :) 507 Movements is a work of art and inspirational.
varenc 6y ago
I love this site! It reminds me on the “early” internet. Dedication to a niche interest without any other fluff.
- deleted 6y ago
  [deleted]
- jacquesm 6y ago
  Exactly my choice of words :) But you beat me to it by an hour or so, have an upvote.
- Dudideloo 6y ago
  It's actually a website from the early internet : http://animatedengines.com/history.html http://animatedengines.com/history.html
TimBurr 6y ago
If you like this, you'll probably enjoy Elmer's Engines. It's an old book full of steam engine plans, designed for people who are new to machining. I used some of them as blueprints when I took drafting in high school. http://www.john-tom.com/html/ElmersEngines.html http://www.john-tom.com/html/ElmersEngines.html
elwell 6y ago
When I stare at these animations I can almost hear sounds.
- marcodiego 6y ago
  Possibly related effect:https://www.cambridgebrainsciences.com/more/articles/why-most-people-hear-sound-in-this-silent-animation https://www.cambridgebrainsciences.com/more/articles/why-mos...
eigenvalue 6y ago
I really love the content here but it looks so pixelated on my high-dpi monitor. It would be awesome is someone remade something like this but using modern web technologies (maybe Lottie from Airbnb) that uses vectorized images that can scale to any size.
carapace 6y ago
No Tesla turbine? I guess it would be too boring. (I know it's bad form to explain a joke, but I'm going to anyway. The Tesla turbine used to be legendary (as in "urban legend") before the Internet. Anyway, it has only one moving part which is radially symmetrical and rotates about its center so there would be nothing to see in the animation!)
jacquesm 6y ago
I love websites like these. No fluff, just good quality content.
cstross 6y ago
Needs more Napier Deltic: https://en.wikipedia.org/wiki/Napier_Deltic https://en.wikipedia.org/wiki/Napier_Deltic (It's a two-stroke cycle diesel but not as we know it -- three cylinders arranged in a triangle with a crankshaft at each vertex, one of them counter-rotating relative to the other two, and six pistons, two of them opposed in each cylinder! There is an animation on the wikipedia page. Tracking it will make your head hurt. This thing was a mainstay of the British railway industry in the late 1950s to 1960s ...)
- jacquesm 6y ago
  That's a pretty clever design, thank you for posting this, I never even heard of it before. I really like the opposing piston trick to get rid of the heavy head, but it does make you wonder how they dealt with the spot where the fuel has to be injected, it's hard enough to get reasonably efficient combustion when you're injecting into the center of the cavity. Did it use multiple injectors per cylinder?
  - rleigh 6y ago
    This part is dead simple and quite clever. It's on the animated diagram in dark blue, and you can also see one port on the cutaway engine block photo (I've been to see this in real life; the engineering is phenomenal). On the blue diagram I think it's air+fuel at one end and exhaust at the other. When the pistons reach their maximum opposing distance, the injection and exhaust ports are briefly exposed, allowing for entry of fuel/air and exit of exhaust in a single linear movement from one end of the cylinder to the other. Maybe the air is injected before the fuel or at a higher pressure. And if you time the speed of the exchange just right in time for the exhaust ports to be closed over before the compression stroke, you get complete exchange with no fuel wastage. Absolutely nothing like a 4-stroke engine, and not much like common 2-stroke designs either.
    - jacquesm 6y ago
      Clever, and no valves to adjust. I really like this design, and I'm wondering why it never caught on more, it looks as though it would have worked well in a boxer like engine as well, instead of two camshafts and one crank you'd end up with no camshafts and two cranks.
tim333 6y ago
Cool though their turbofan isn't going to work very well with the compressor being much larger than the turbine - the gas would find it easier to flow the wrong way. The Wikipedia animation has more promising dimensions https://en.wikipedia.org/wiki/Turbofan https://en.wikipedia.org/wiki/Turbofan
- zxczxczxcf 6y ago
  After remarking on how boring jet engines are, the page gets vague and states that the turbofan increases "fuel efficiency", without explaining why or how. I've seen it assumed elsewhere that the efficiency of turbofans is due to thermodynamic effects. In this case, what the author wrote is vague about the mechanics of it, at best. In fact, turbofans have better propulsive efficiency because they accelerate more air to a lower speed. Fuel efficiency follows from that. https://en.wikipedia.org/wiki/Propulsive_efficiency#Jet_engines https://en.wikipedia.org/wiki/Propulsive_efficiency#Jet_engi...
- mrfusion 6y ago
  This has baffled me since I was two years old. The burning fuel should push in all directions equally. What makes it go more out the back than the front?
  - rleigh 6y ago
    That's what all the compressor stages are for. There's a pressure differential so the combustion pushes against that and exits in one direction, turning the lower pressure discs on its way out.
  - benlivengood 6y ago
    It's easier if you imagine identical fans for the compressor and turbine but gearing so the turbine can spin faster. Of course the gasses will take the easy way out the turbine. At some speed, air stops going out the compressor and comes in instead. Burning fuel keeps the gas expanding so there's still a lot more volume to go through the turbine. Then adjust blade angles and turbine diameters to get rid of the gearing.
mcguire 6y ago
Adding to the "if you like this" chain, the vbbsmyt YouTube channel has 3d animations of historic guns and other weapons. https://www.youtube.com/channel/UCFOZwUakpRbIH2zisiRU0Dw https://www.youtube.com/channel/UCFOZwUakpRbIH2zisiRU0Dw
elihu 6y ago
Probably worth mentioning LiquidPiston's new rotary engine design (which has been discussed on HN before): https://www.liquidpiston.com/how-it-works https://www.liquidpiston.com/how-it-works (It's like an inside-out Wankel engine. Instead of a triangular rotor in an oval housing, it's an oval rotor in a triangular housing. The advantage is you get a more optimally-shaped combustion chamber, which ought to improve fuel economy and emissions. Also the apex seal-equivalents are easier to lubricate as they're attached to the housing rather than the rotor. They've made a few prototypes and they're working on durability.)
- mberning 6y ago
  Interesting twist on a Wankel style design. It looks like the apex seals are moved to the block rather than rotor. I’m also curious as to the benefit/drawback of having the flow of intake and exhaust perpendicular to the rotor.
mrfusion 6y ago
If we ever had a high altitude electric plane do we think electric motors with huge props? Or would we try to recreate the turbo jet? Maybe resistive heating elements instead of fuel?
- mberning 6y ago
  It would most likely emulate a turbofan, replacing the core with an electric motor and possibly a gearbox.
dang 6y ago
If curious, past threads: Animated Engines - https://news.ycombinator.com/item?id=7127953 https://news.ycombinator.com/item?id=7127953 - Jan 2014 (34 comments) Animated Engines - https://news.ycombinator.com/item?id=701186 https://news.ycombinator.com/item?id=701186 - July 2009 (11 comments)
jonplackett 6y ago
It would be cool to see some Heath Robinson contraptions animated like this!
- mhh__ 6y ago
  One of my dreams for the next few years is that computers are now fast enough to have physically realistic simulations in games - you might not be waiting for too long to be building Heath Robinson machines in VR!
  - jonplackett 6y ago
    First thing I would build: recreation of the mousetrap board game.
Vektorweg 6y ago
These are pretty cool. Worth to spend some time turning these into continuous SVG.
- cableclasper 6y ago
  I'd like to do this. Can you recommend a good starting place to learn how?
  - bobsterman 6y ago
    Start with drawing a single frame with SVG [1], then add animation with CSS [2] or Javascript. [1] https://developer.mozilla.org/en-US/docs/Web/SVG/Tutorial/Basic_Shapes https://developer.mozilla.org/en-US/docs/Web/SVG/Tutorial/Ba... [2] https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Animations/Using_CSS_animations https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Animati...
    - cableclasper 6y ago
      Thank you!
retsibsi 6y ago
This is excellent, thanks for sharing it. One neat feature it took me a moment to notice: you can step through the animations manually, if you hit the pause button and then either drag the slider or click the arrow buttons.
benlivengood 6y ago
Lol at the hate that jet engines get for being too "simple" and "boring". I think some of the compressor/turbine blades are drawn the wrong angle but jet engines have always looked to me like they shouldn't work at all. I know that the turbine extracts more force from exhaust than the compressor exerts on the air (while spinning up) but it's all in the diameter and blade shape since they're attached to the same shaft, and my intuition has trouble wrapping around the concept.
p1mrx 6y ago
The FPLG might be a good addition, though it's interesting because of how boring it is: https://en.wikipedia.org/wiki/Free-piston_linear_generator https://en.wikipedia.org/wiki/Free-piston_linear_generator https://www.youtube.com/watch?v=eV7f3tOUEbU https://www.youtube.com/watch?v=eV7f3tOUEbU
mrfusion 6y ago
So I’m the two stroke what pushes the exhaust out? Wouldn’t it mix with the intake? Also Is it possible to build a clean two stoke?
- TimBurr 6y ago
  You're asking really good questions :) In my layman's understanding, those are related. Playing with the piston dimensions limits (but doesn't entirely prevent) fuel/exhaust mixing. Unburned fuel in the exhaust makes them dirty. The site says: > ... This expels the exhaust gasses out the exhaust port, usually located on the opposite side of the cylinder. Unfortunately, some of the fresh fuel mixture is usually expelled as well. Another factor - since the fuel enters through the crankcase, it needs to be mixed with oil for lubricating the moving parts. That oil burns when it gets to the combustion chamber. Pretty sure that also increases unwanted emissions. It's entirely possible modern CFD and chemistry could improve on those issues... I'd be curious if anyone else knows about recent R&D on two-strokes. They're hard to beat on power-to-weight.
  - SigmundA 6y ago
    Direct injection two-strokes like ETEC's avoid the burnt fuel in the exhaust by not injecting any fuel until the exhaust port is closed. They also typically have specific oil injection points reduce the amount of oil needed to be burned. They are generally as clean as modern 4-stroke engine.
    - TimBurr 6y ago
      Thanks for the reference! I'll have to read about those more. Sounds like that also eliminates any fuss with oil/fuel ratios, since they're introduced separately.
MattSayar 6y ago
There's a lot of engines I've never heard of here, but my new Subaru Outback has a CVT (Continuously Variable Transmission) which isn't represented here which is somewhat disappointing
- grkvlt 6y ago
  not an engine, but (in the name...) a transmission - a mechnism for transmitting power from the engine to the wheels. normally cars use a gearbox (automatic or manual) and possibly a driveshaft (to connect to the wheels that are at the other end from the engine.)
- h2odragon 6y ago
  You might enjoy this: https://hackaday.com/2021/02/05/building-a-continuously-variable-transmission-with-lego/ https://hackaday.com/2021/02/05/building-a-continuously-vari...
fartcannon 6y ago
We used these animations as visual aids in my undergrad approximately 18 years ago, give or take a year. It's marvelous that they're still here.
hliyan 6y ago
A long shot, but hope they could include the Wave Disk Engine (https://en.wikipedia.org/wiki/Wave_disk_engine https://en.wikipedia.org/wiki/Wave_disk_engine). I could never wrap my head around the operating principle. Also, the research appears to be either slow going, or halted.
- ActorNightly 6y ago
  >the rotation of the disk creates shockwaves The engineer in me cringed at this. While you can definitely use shockwaves to compress the air, dealing with the repeated stresses to the engine casing and other parts is a nightmare.
jimkleiber 6y ago
It's posts like this that keep the nerd in me glued to HN.
AlexFielder 6y ago
Surprised nobody mentioned the MYT engine: http://angellabsllc.com/ http://angellabsllc.com/
coolgeek 6y ago
Do not miss the sister site http://507movements.com/ http://507movements.com/

696 points by marcodiego 6y ago

This is neat. If someone wants a slightly more comedic take on automotive engine designs, Donut Media has some interesting content. https://www.youtube.com/watch?v=8YIDOjD0oBI https://www.youtube.com/watch?v=8YIDOjD0oBI EDIT: Removed erroneous claim.

capableweb 6y ago
> Donut Media pioneered the "suck squeeze bang blow" descriptor of the 4 stroke engine Someone please correct me if I'm wrong but I think I've heard the term "suck squeeze bang blow" way before Feb 23, 2021 and also before 2015 (creation of that Youtube channel) so I find that claim hard to believe.
- bagels 6y ago
  It predates that channel by decades.
- Judgmentality 6y ago
  Sorry, it's just the first place I'd heard it. I'll edit my comment. I wasn't speaking on behalf of them. Weird. I've been talking to people about cars for decades and I'd never heard it before them. Is it just something that people don't say anymore? https://mechanics.stackexchange.com/questions/28682/who-came-up-with-suck-squeeze-bang-blow https://mechanics.stackexchange.com/questions/28682/who-came... I guess for whatever reason it's just not used as much, or at least not enough that I've heard it before.
- pen2l 6y ago
  This text dated 1981 mentions it (page viii): https://link.springer.com/content/pdf/bfm%3A978-1-349-06976-7%2F1.pdf https://link.springer.com/content/pdf/bfm%3A978-1-349-06976-... edit: and googling some more, there are instances of in being used it 1950s. And the likely first author of the saying might well be the inventor of the 4 stroke engine himself, Nicolaus Otto, who used a similar saying to describe it: Saugen, Drücken, Knall, Schlag.
  - wizzwizz4 6y ago
    Only source I can find for your last claim is https://mechanics.stackexchange.com/a/28690/33924 https://mechanics.stackexchange.com/a/28690/33924: > Actually, I wouldn't be surprised if the great Nikolaus August Otto, inventor of the four-cycle engine had a similar saying to explain his engine: Saugen, Drücken, Knall, Schlag... So I think this is apocryphal.
    - pen2l 6y ago
      You might be right, I'm not sure. At least in Otto's patent filing (which is found in English here: https://patentimages.storage.googleapis.com/1f/3f/4c/821c6da1070930/US194047.pdf https://patentimages.storage.googleapis.com/1f/3f/4c/821c6da... ) I don't see such an expression. I do see though that the breakdown of the Otto cycle on most sites including German ones (https://de.wikipedia.org/wiki/Ottomotor https://de.wikipedia.org/wiki/Ottomotor) is usually made in a way that just sorts of lends itself to being transformed that way. Well, thanks for making me go through his writings, this was fun!
- cableclasper 6y ago
  Yeah. I've seen it in an old BBC documentary: The secret life of machines - Internal Combustion Engine https://www.youtube.com/watch?v=gfr3_AwuO9Y https://www.youtube.com/watch?v=gfr3_AwuO9Y
- NikolaeVarius 6y ago
  Wow screw this channel for such dumb shit.
- mhh__ 6y ago
  Even top gear referred to it as such probably a decade prior
berniemadoff69 6y ago
> If someone wants a slightly more comedic take it seems sort of rare on the Internet, particularly in videos, for someone to NOT be doing a 'comedic' take, along with a jump cut every 5 seconds, background music; all kinds of stuff that feels like it is desperately trying to do everything it can all at once to make someone not hit the back button. ironically, hitting the back button is the first thing i do when a video starts with 'Wats up Guyz' or something along those lines. the original post is a breath of fresh air, straight to the point. I wish the Internet was more like this in general.
- marcodiego 6y ago
  These "jump cut every 5 seconds" is the reason I've been watching less youtube everyday. It completely breaks continuity and are so frequent that a significant part of the video is wasted. Reading and watching an animation is better than video tutorials in almost every regard.
spike021 6y ago
Something to keep in mind: several sources of actual topics have contradicted Donut Media views on certain things and DM has been known to steal video clips without crediting where they got them or use Wikipedia articles as established sources. Not that all their videos have these issues, but some do and it gets pretty ridiculous.

amelius 6y ago

How do you drive the fuel into the highly compressed chamber, in case of the Diesel engine?

capableweb 6y ago
The diesel engine is found here for the record: http://animatedengines.com/diesel.html http://animatedengines.com/diesel.html Short answer: you need a fuel injector that can handle injection into the highly-compressed air. Longer answer: https://www.britannica.com/technology/diesel-engine/Fuel-injection-technology https://www.britannica.com/technology/diesel-engine/Fuel-inj...
jcampbell1 6y ago
Until very recently, the injector works by a push rod from the cam shaft, meaning it is powered the same way the valves are. In modern engines you have other options such as an electric piezo stack hammer to force the fuel.
- SigmundA 6y ago
  You might be conflating how an injector turns on and if with how the fuel is pressurized. Unit injectors create the high pressure for injection in the injector, combining the high pressure pump and injector in one, fed by a low pressure rail. Theses are driven mechanically via cams to create pressure. Common high pressure rail injectors have a separate high pressure pump connected to engine elsewhere and the injectors just turn on and off fed by a high pressure common rail. The injector itself can be actuated mechanically or via solenoids or piezo, but there are no injectors that create pressure electrically that I know of (the closest I have seen are voicemail medium pressure gas injectors used in ETEC engines). That is the electric part of the injector only lets the fuel through, it does not force it.
dugditches 6y ago
via a 'fuel/injector pump'. Can click through this to get an idea of just how complicated(and analog) they are. https://www.youtube.com/watch?v=DKZL7Y0b5-U https://www.youtube.com/watch?v=DKZL7Y0b5-U

prashnts 6y ago

Quite interesting! Reminds me of http://507movements.com/ http://507movements.com/ Edit: It’s linked in the website as a “sister site”.

ourcat 6y ago
I was about to say the exact same thing. :) 507 Movements is a work of art and inspirational.

varenc 6y ago

I love this site! It reminds me on the “early” internet. Dedication to a niche interest without any other fluff.

deleted 6y ago
[deleted]
jacquesm 6y ago
Exactly my choice of words :) But you beat me to it by an hour or so, have an upvote.
Dudideloo 6y ago
It's actually a website from the early internet : http://animatedengines.com/history.html http://animatedengines.com/history.html

TimBurr 6y ago

If you like this, you'll probably enjoy Elmer's Engines. It's an old book full of steam engine plans, designed for people who are new to machining. I used some of them as blueprints when I took drafting in high school. http://www.john-tom.com/html/ElmersEngines.html http://www.john-tom.com/html/ElmersEngines.html

elwell 6y ago

When I stare at these animations I can almost hear sounds.

marcodiego 6y ago
Possibly related effect:https://www.cambridgebrainsciences.com/more/articles/why-most-people-hear-sound-in-this-silent-animation https://www.cambridgebrainsciences.com/more/articles/why-mos...

eigenvalue 6y ago

I really love the content here but it looks so pixelated on my high-dpi monitor. It would be awesome is someone remade something like this but using modern web technologies (maybe Lottie from Airbnb) that uses vectorized images that can scale to any size.

carapace 6y ago

No Tesla turbine? I guess it would be too boring. (I know it's bad form to explain a joke, but I'm going to anyway. The Tesla turbine used to be legendary (as in "urban legend") before the Internet. Anyway, it has only one moving part which is radially symmetrical and rotates about its center so there would be nothing to see in the animation!)

jacquesm 6y ago

I love websites like these. No fluff, just good quality content.

cstross 6y ago

Needs more Napier Deltic: https://en.wikipedia.org/wiki/Napier_Deltic https://en.wikipedia.org/wiki/Napier_Deltic (It's a two-stroke cycle diesel but not as we know it -- three cylinders arranged in a triangle with a crankshaft at each vertex, one of them counter-rotating relative to the other two, and six pistons, two of them opposed in each cylinder! There is an animation on the wikipedia page. Tracking it will make your head hurt. This thing was a mainstay of the British railway industry in the late 1950s to 1960s ...)

jacquesm 6y ago
That's a pretty clever design, thank you for posting this, I never even heard of it before. I really like the opposing piston trick to get rid of the heavy head, but it does make you wonder how they dealt with the spot where the fuel has to be injected, it's hard enough to get reasonably efficient combustion when you're injecting into the center of the cavity. Did it use multiple injectors per cylinder?
- rleigh 6y ago
  This part is dead simple and quite clever. It's on the animated diagram in dark blue, and you can also see one port on the cutaway engine block photo (I've been to see this in real life; the engineering is phenomenal). On the blue diagram I think it's air+fuel at one end and exhaust at the other. When the pistons reach their maximum opposing distance, the injection and exhaust ports are briefly exposed, allowing for entry of fuel/air and exit of exhaust in a single linear movement from one end of the cylinder to the other. Maybe the air is injected before the fuel or at a higher pressure. And if you time the speed of the exchange just right in time for the exhaust ports to be closed over before the compression stroke, you get complete exchange with no fuel wastage. Absolutely nothing like a 4-stroke engine, and not much like common 2-stroke designs either.
  - jacquesm 6y ago
    Clever, and no valves to adjust. I really like this design, and I'm wondering why it never caught on more, it looks as though it would have worked well in a boxer like engine as well, instead of two camshafts and one crank you'd end up with no camshafts and two cranks.

tim333 6y ago

Cool though their turbofan isn't going to work very well with the compressor being much larger than the turbine - the gas would find it easier to flow the wrong way. The Wikipedia animation has more promising dimensions https://en.wikipedia.org/wiki/Turbofan https://en.wikipedia.org/wiki/Turbofan

zxczxczxcf 6y ago
After remarking on how boring jet engines are, the page gets vague and states that the turbofan increases "fuel efficiency", without explaining why or how. I've seen it assumed elsewhere that the efficiency of turbofans is due to thermodynamic effects. In this case, what the author wrote is vague about the mechanics of it, at best. In fact, turbofans have better propulsive efficiency because they accelerate more air to a lower speed. Fuel efficiency follows from that. https://en.wikipedia.org/wiki/Propulsive_efficiency#Jet_engines https://en.wikipedia.org/wiki/Propulsive_efficiency#Jet_engi...
mrfusion 6y ago
This has baffled me since I was two years old. The burning fuel should push in all directions equally. What makes it go more out the back than the front?
- rleigh 6y ago
  That's what all the compressor stages are for. There's a pressure differential so the combustion pushes against that and exits in one direction, turning the lower pressure discs on its way out.
- benlivengood 6y ago
  It's easier if you imagine identical fans for the compressor and turbine but gearing so the turbine can spin faster. Of course the gasses will take the easy way out the turbine. At some speed, air stops going out the compressor and comes in instead. Burning fuel keeps the gas expanding so there's still a lot more volume to go through the turbine. Then adjust blade angles and turbine diameters to get rid of the gearing.

mcguire 6y ago

Adding to the "if you like this" chain, the vbbsmyt YouTube channel has 3d animations of historic guns and other weapons. https://www.youtube.com/channel/UCFOZwUakpRbIH2zisiRU0Dw https://www.youtube.com/channel/UCFOZwUakpRbIH2zisiRU0Dw

elihu 6y ago

Probably worth mentioning LiquidPiston's new rotary engine design (which has been discussed on HN before): https://www.liquidpiston.com/how-it-works https://www.liquidpiston.com/how-it-works (It's like an inside-out Wankel engine. Instead of a triangular rotor in an oval housing, it's an oval rotor in a triangular housing. The advantage is you get a more optimally-shaped combustion chamber, which ought to improve fuel economy and emissions. Also the apex seal-equivalents are easier to lubricate as they're attached to the housing rather than the rotor. They've made a few prototypes and they're working on durability.)

mberning 6y ago
Interesting twist on a Wankel style design. It looks like the apex seals are moved to the block rather than rotor. I’m also curious as to the benefit/drawback of having the flow of intake and exhaust perpendicular to the rotor.

mrfusion 6y ago

If we ever had a high altitude electric plane do we think electric motors with huge props? Or would we try to recreate the turbo jet? Maybe resistive heating elements instead of fuel?

mberning 6y ago
It would most likely emulate a turbofan, replacing the core with an electric motor and possibly a gearbox.

dang 6y ago

If curious, past threads: Animated Engines - https://news.ycombinator.com/item?id=7127953 https://news.ycombinator.com/item?id=7127953 - Jan 2014 (34 comments) Animated Engines - https://news.ycombinator.com/item?id=701186 https://news.ycombinator.com/item?id=701186 - July 2009 (11 comments)

jonplackett 6y ago

It would be cool to see some Heath Robinson contraptions animated like this!

mhh__ 6y ago
One of my dreams for the next few years is that computers are now fast enough to have physically realistic simulations in games - you might not be waiting for too long to be building Heath Robinson machines in VR!
- jonplackett 6y ago
  First thing I would build: recreation of the mousetrap board game.

Vektorweg 6y ago

These are pretty cool. Worth to spend some time turning these into continuous SVG.

cableclasper 6y ago
I'd like to do this. Can you recommend a good starting place to learn how?
- bobsterman 6y ago
  Start with drawing a single frame with SVG [1], then add animation with CSS [2] or Javascript. [1] https://developer.mozilla.org/en-US/docs/Web/SVG/Tutorial/Basic_Shapes https://developer.mozilla.org/en-US/docs/Web/SVG/Tutorial/Ba... [2] https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Animations/Using_CSS_animations https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Animati...
  - cableclasper 6y ago
    Thank you!

retsibsi 6y ago

This is excellent, thanks for sharing it. One neat feature it took me a moment to notice: you can step through the animations manually, if you hit the pause button and then either drag the slider or click the arrow buttons.

benlivengood 6y ago

Lol at the hate that jet engines get for being too "simple" and "boring". I think some of the compressor/turbine blades are drawn the wrong angle but jet engines have always looked to me like they shouldn't work at all. I know that the turbine extracts more force from exhaust than the compressor exerts on the air (while spinning up) but it's all in the diameter and blade shape since they're attached to the same shaft, and my intuition has trouble wrapping around the concept.

p1mrx 6y ago

The FPLG might be a good addition, though it's interesting because of how boring it is: https://en.wikipedia.org/wiki/Free-piston_linear_generator https://en.wikipedia.org/wiki/Free-piston_linear_generator https://www.youtube.com/watch?v=eV7f3tOUEbU https://www.youtube.com/watch?v=eV7f3tOUEbU

mrfusion 6y ago

So I’m the two stroke what pushes the exhaust out? Wouldn’t it mix with the intake? Also Is it possible to build a clean two stoke?

TimBurr 6y ago
You're asking really good questions :) In my layman's understanding, those are related. Playing with the piston dimensions limits (but doesn't entirely prevent) fuel/exhaust mixing. Unburned fuel in the exhaust makes them dirty. The site says: > ... This expels the exhaust gasses out the exhaust port, usually located on the opposite side of the cylinder. Unfortunately, some of the fresh fuel mixture is usually expelled as well. Another factor - since the fuel enters through the crankcase, it needs to be mixed with oil for lubricating the moving parts. That oil burns when it gets to the combustion chamber. Pretty sure that also increases unwanted emissions. It's entirely possible modern CFD and chemistry could improve on those issues... I'd be curious if anyone else knows about recent R&D on two-strokes. They're hard to beat on power-to-weight.
- SigmundA 6y ago
  Direct injection two-strokes like ETEC's avoid the burnt fuel in the exhaust by not injecting any fuel until the exhaust port is closed. They also typically have specific oil injection points reduce the amount of oil needed to be burned. They are generally as clean as modern 4-stroke engine.
  - TimBurr 6y ago
    Thanks for the reference! I'll have to read about those more. Sounds like that also eliminates any fuss with oil/fuel ratios, since they're introduced separately.

MattSayar 6y ago

There's a lot of engines I've never heard of here, but my new Subaru Outback has a CVT (Continuously Variable Transmission) which isn't represented here which is somewhat disappointing

grkvlt 6y ago
not an engine, but (in the name...) a transmission - a mechnism for transmitting power from the engine to the wheels. normally cars use a gearbox (automatic or manual) and possibly a driveshaft (to connect to the wheels that are at the other end from the engine.)
h2odragon 6y ago
You might enjoy this: https://hackaday.com/2021/02/05/building-a-continuously-variable-transmission-with-lego/ https://hackaday.com/2021/02/05/building-a-continuously-vari...

fartcannon 6y ago

We used these animations as visual aids in my undergrad approximately 18 years ago, give or take a year. It's marvelous that they're still here.

hliyan 6y ago

A long shot, but hope they could include the Wave Disk Engine (https://en.wikipedia.org/wiki/Wave_disk_engine https://en.wikipedia.org/wiki/Wave_disk_engine). I could never wrap my head around the operating principle. Also, the research appears to be either slow going, or halted.

ActorNightly 6y ago
>the rotation of the disk creates shockwaves The engineer in me cringed at this. While you can definitely use shockwaves to compress the air, dealing with the repeated stresses to the engine casing and other parts is a nightmare.

jimkleiber 6y ago

It's posts like this that keep the nerd in me glued to HN.

AlexFielder 6y ago

Surprised nobody mentioned the MYT engine: http://angellabsllc.com/ http://angellabsllc.com/

coolgeek 6y ago

Do not miss the sister site http://507movements.com/ http://507movements.com/