Rotating Detonation Engine (RDE) -- Dynamics and Bifurcations
Вставка
- Опубліковано 7 чер 2024
- PAPER 1
Physical Review Paper: journals.aps.org/pre/abstract...
ArXiv link: arxiv.org/abs/1908.03116
PAPER 2
ArXiv link: arxiv.org/abs/2003.06655
This video details many of the spatio-temporal dynamics exhibited in rotating detonation rocket engines (RDEs), including combustion front interactions that behave like solitons. A complete bifurcation analysis of the dynamics is performed showing that our multi scale, dynamical model captures all the salient features of the combustion dynamics.
Who's also here after Scott Manley's video?
yep
yeah, thinking of looking into pulse and rotation detonaton engins for my BEng and MEng projects because of it
nope, been looking for ring detonation engines since some nut crack talked about the ghost plane Aurora that supposedly had a full body aerospike ring detonation engine that ran on some shock sensitive metyl mercury compound. The fuselage was the ring inner wall and the hyper sonic shock-wave was the outer. They stopped flying it because the immense mercury pollution gave it away. Obviously all complete bs.
Yep, I really hope we get these engines in KSP2
That and the fact that this reminded me of DARPA and Boeing's Blackswift program where they were trying to test out new vehicle designs for SSTO, could have sworn the wiki on the Blackswift project at one point in time stated they were using a PDE... Ohh well
He presents this so calmly as if it isn't a big deal. Rotating detonation engines are the holy grail of combustion chambers. This guy is going to change the way we build rocket engines in 25 years, yet no one knows his name. He surely deserves the PHD. Godspeed young man!
Holy crap its so refreshing to see youtube content that doesn't sugar coat the complexities of these types of computational models. Noticed the papers aren't linked in the description like he mentions towards the end of the video. I'd be interested in seeing what kinds of solve times these models have been yielding, and if it would allow for nesting the model inside a parametric optimization study to find optimal configurations in terms of thermal efficiency. Really great content, keep up the great work!!
The mathematical model is not very complex so my sense of it is it wouldn't take more than a few minutes for simple solutions and not more than a couple hours for a more complex evolution of behavior on a single fast pc core. So worst case I would guess with an 8 core cpu about 10 days for a 1000 runs for doe analysis which would only take an hour or so. The problem is at the moment he only has qualitative confirmation he would nedd to refine the model with at least a few constants to obtain quantitative conformity to do an optimization.
@@RamPenndragon I remember watching a us air force video from the edwards afb channel where they mentionned that a full simulation including pressure and temperature took them a month to run, there weren't any details though
This guy is a great teacher! Wish he could do a question and answer session.
This is really interesting even though I don't understand half of it
Same here. Not only interesting, it's very beautiful. Yet, most of the stuff is just Alien language to me.
We need some popular language translator.
@@temukaify These technical terms do have some slightly specific meanings but none of them are rocket science (haha)
cicumferentially - around the circle (how the needle rides the record)
radial - back and forth between the center and edge of the circle, 'across' it basically (how you scratch the record)
bifurcation - spliitting into two (pissing two streams instead of one)
tangential - a straight line off the edge of a circle (car sliding off a corner of a track)
detonation - an *extremely* fast form of combustion in which the explosion passes through the material at a speed of miles per second (c4/dynamite, shatters steel)
deflagration - slower, more traditional burning through oxidation of material (gunpowder/fireworks, bends steel)
annulus - ring shaped (lol)
luminosity - how bright something is (setting a dimmer)
pressure gradient - simply a change in pressure over distance (swimming to the bottom of the deep end of the pool)
amplitude modulations - system or process controlling the intensity or power in something (sitting on top of your little brother)
simple harmonic motion - back and forth or circular motion in tune with how the system wants to be have (swinging on a swing normally vs pushing someone slowly back and forth on a swing)
coupling of shock front and heat release leading to stable phase difference between the two detonation waves - essentially just means that energy dumps into a system and back out at just the right speed for the next cycle of the same. (basically just like a small engine running or, more simply, juggling)
Any other words just google them right away. In my opinion this guy isn't doing this to sound smart, he's just up to his eyeballs in this stuff. Like i said all of these terms have kind of specific meanings that only matter when they matter, and sometimes are used to differentiate other terms that could be summarized exactly the same way i do above but mean something different.
@@temukaify He is slightly overdoing it with terms. Stating that the detonations are 1rad or pi or 180 degrees apart is a less clear way of simply saying opposite of each other. Instead of nucleation he could say just start... temporal evolution is just change over time...
Sure, he needs some tough terms to explain this that you and I don't understand, but in the end it becomes a non-explanation if you have to pause the video to find the popular synonym for every other word, even to someone in the field.
@@AdamPitas Eh, he's close to the metal so to speak so I'll give him that. A lot of his terminology is powerful due to the fact that it has cross-disciplinary value, and is telling of his background, which is dynamical systems. The modelling of crap of any kind necessitates these levels of abstractions, and once you define the tough terms and see them used in context, you'll realize that he's surprisingly terse.
Very impressive work! Having the engine built and devising a model that exactly matches the observed characteristics must be a delightful experience. Looking at the PDE one wonders if it would be possible to find closed-form solutions. Engine blow-out dynamics are probably also non-linear and most probably coupled with the rotational dynamics. Stability conditions of engine blow-out is probably a research path based on this work.
Its incredible how the turbo flux encabulator can encorporate twice the texel density, virtually rendering vertical flex inhibited.
And at no time did his hands leave his arms!
Really good video. I loved the description of the oscillitory wave motion of the Shockwaves around the annulus of the combustion chamber. The transient states of the Shockwave formations were very reminiscent, to me, of the transient states of a jet engine and of course you can also get engine surge in a jet engine if the throttle is being increased too quickly across a transient flow regime. I enjoyed the description of the conditions under which the engine would become choked and the stable and unstable (or transient states) that have oscillitory motion and shock wave formation dictated by the amount of energy or fuel that is inject into the combustion chamber. The video really helped me understand, I think, how you can generate a detonation shockwave simply by triggering a deflagration reaction in the annular chamber and allow the pressure differences within the annulus to naturally increase the strength of the flame front over time till detonation occurs
Thanks for not dumbing things down too much.
As a postgraduate space science and technology student, I am shocked, that I have never heard about it before, but this video was extremely well done and I hope this is ready for use on an experimental rocket soon!
I hope its adapted to lazer-fussion.
I'm sure he's working on the successor to Aurora and is precluded by top secret restrictions from ever publicly speaking on this subject again.
This type of rocket engine has been in the works for decades now, and rumor mill has it that the Air Force or an adjoining technology office/agency like darpa has tested aircraft equipped with such engines (and that was in the 90’s) remember the government classifies advanced technologies and restricts the private sector from usi bc such advanced techniques/technologies which has any sort of national security concern attached to said technology due to the techniques and technologies used. Just look up the boscombe down incident 1994, this incident was speculated to be possibly an air breathing detonation engine given the response and most likely flight pattern flown. Also given the time frame there was adjoining evidence like photos of what looked to be a pulsed detonation exhaust trail from an unknown aircraft at high altitude as well as sonic booms record by seismographs off the Californian coast which put the aircraft at Mach 3+ bare minimum (and this wasn’t the SR-71 flying it’s last missions given the flight patterns reconstructed from the seismic readings which also put it at high altitudes…) very interesting stuff, but this is the type of stuff the government does everything in their power to suppress information about to the public…) cheers
@@sadface7457 no need to do that if you were hypothetically using a laser fusion drive
Right up against the limits of my grasp! Thank you!
Very exciting and a beautiful process.
Thanks for posting this for general public to see. Very few rotating detonation engine exploration videos on yt
This was amazing, thank you. I'm currently studying mechanical engineering and would gladly hear more on where to look and what to read to get more into detonation models, supersonic flow etc. Thank you.
Very well done. I enjoyed this very much!
Very informative and awesome presentation!
It's been a little over a year since this was published - what's new? I would love to see a follow up of what has been learned in the last 18 months.... or even what you need to further the research and big challenges to overcome. great work!
This is an amazing application of the Burgers'-equation-based detonation analog in capturing some intrinsic wave features in RDEs. The analysis is very inspirational. I'll be staying tuned for the future work. A little suggestion: The lack of backward running characteristics in Burgers' equation limits the current model from capturing counter-rotating detonation waves. The use of the shallow water equation might be explored to construct an RDE-detonation analog model.
Okay, I'm a high school math teacher....and this stuff is WAY over my head!! I'd like to know what math courses he took in high school to help prepare him for the college courses he took (or is taking). What did his high school teachers do or not do that engaged him? Were his not-so-great teachers at least "okay"? Oh, and another thing (sorry, I keep editing my post), it would be GREAT if he could send this video to all of his high school math and science teachers. Some may think he's trying to show off, maybe??? But if I were one of his teachers, it would make my day knowing that I may have added a tiny piece towards making this video! :)
Most engineers who are passionate about their craft will seek out resources on their own, that's what I did, and I'm sure PhD. Kutz is no different.
Trigonometry. Conversion of the radial coordinates of the wave as it travels around the annulus is nothing more than the unit circle. Maybe the next time you teach the unit circle, you give them the video and ask them to convert from radial to Cartesian coordinates?
Honestly though, most engineers can do math, but it's not a source of great joy (those guys gravitate more toward physics.) So hang in there all you math teachers - people need to understand it even if they don't enjoy it.
Come on! It's not rocket science ... oh wait, it is! ;-) lol
The signs of a great teacher! Glad to know you're still out there
Rocket science, physics, engineering, design, math and computation
Fascinating, thank you for sharing.
Awesome presentation.
Thank You, found this very interesting!
Excellent presentation for us engineering types, simplified enough for us to understand but not dumbed down to much... I am familiar with pulsed detonation concepts but previously never grasped the potential advantages of a rotating system and its stability problems. Remember reading something (Los Alamos report perhaps? ) long time ago about stabilizing combustion by electromagnetic means by MHD type action. Wonder if something like that could perhaps be used to force the desired mode in the combustion chamber.
Thanks! The names of mathematical functions helps begin a search. The equation you used, exactly, would save my time. The combustion precursors, their densities and flow rate changes as the wave propagates circumferential, would also be interesting parameters, if you have them available. The dimensions of your combustion annulus would also be interesting. Your overview suggests a close correlation between the variations in combustion dynamics and dimensions of your experimental setup.
That was a very good presentation. In some of those earlier plots it looks like there are some traveling waves propagating in the reverse direction. Its like you have some reflections going on, its very similar to how standing waves establish on transmission lines.
Look up bewley lattice diagram.
Very cool stuff! I'd like to know the sensitivity of parameters in the models. ie, how "finely tuned" do the parameters need to be to reproduce real-world results. An overly sensitive model is too chaotic to be used predictivly in industry. Time to find those papers and start reading!
I wanted to say that I have been interested in all types of engines whether internal combustion or detonation engine and their variants such as Wankel engines and all manner of rocket engines like steam or even detonation rocket engines. Thank you for this video as it is amazing material to reference and learn from.
This is awesome - hope he gets hired by one of the big space firms and makes it happen!
Thanks for your compliments Stephen. I think you underestimate my higher level of study, that is why the 8 th high school grade is the ambitious goal I set myself.
Nothing is never too late to go there, especially at my advanced age because i am 58 years
now give my 500 isp rockets
This very cool. Wow. Smart young fellow.
yey, the model works/reproduces!
Great presentation. I wonder how you created this video. How do you point the slides from behind? Are they projected on a semi-transparent screen?
I was just looking at suspending droplets in midair using soundwaves, and I wondered if this process could be used in an engine. Come to find out, this RDE concept seems to basically be the best way to revolutionize chemical rocket tech, being that this way MUCH more power is extracted.
This is some lovely visualisations of the process. I would like to know both more about how these pictures were taken, how much they are slowed down, and what the spatial scale is so we can get an idea of the velocities that the detonation waves are traveling.
Also having some idea of what the frequency of GM radiation being recorded is, what the peak is so that we can get an idea of what the temperatures are
Wow this is really cool
You ought to do another version of it similar to Chrysler's Encabulator video.
This is so cool
I wonder what kind of information you can gleam from the detonation tone
Hi, great video! have you considered the use of Tesla valves to control the direction of the propagating wave? this will not solve all issues but will help with predicting which direction the wave will move.
Super cool!
I feel like the most interesting question is how many waves do you need to maximize the thrust generated over the long term (particularly what do you need to do to have the thrust/weight of contraption be greater than 1)?
On your combustion tube have you considered a helical rifled tube? Also consider the helical channel depth for a low pressure and increased velocity of the channels of the helical combustion tube. If you were to do that I would make the helical rifling channels smooth like rolling hills. You may want to play around with the injectors in the helical channels for stabilization of your timing phase, as the fuel will follow the low pressure zone in the channels of the helical tube along with the timing phase. Good luck.
Nathan please do a Q and A and please do a laymans video showing all the ways this is a game changer? For example times to moon and mars! This work is very valuable as Space is the next battlespace of this century! The numbers are so fascinating! How it slows down and self steppens was weird in the creation of the next wave? Weird and amazing Nathan! Mode locked pulses!
Scott Manley's UA-cam par on RDEs and their problems and possibilities is exactly what you are after.
Those equations are just elegant! The hallmark of any great formula. I am guessing the speed of the detonation wave is largely dependent on fluid-composition?
Given the shape of this sort of engine, I wonder if an aerospike could be more easily used to guide the exhaust?
Given the amount of energy in the shock wave from a detonation you might not even want a bell. Most of the energy will have left the building by the time the combustion catches up. A long expansion chamber might just wind up cooling the exhaust too much.
That's what they did at the Warsaw University back in 2011. They stuck an annular aerospike nozzle on a rotating detonation engine. Interesting experiment.
@@jcims There probably is a sweetspot for bell-length to exhaust cooling in terms of efficiency.
@@JainZar1 yes exactly you would be able to calculate exactly given your system what the optimal bell length or aero spike length should be given your system/engine being used no different than from regular rocket engines
Amazing stuff. I wish I had better introduction to physics when I was a kid. Working on such things must be amazing. I am just a passionate 3d artist, so I have no real business in it, but:
1. When can we expect first functional engines like this?
2. What kind of nozzle would they use? Aerospike? Some kind of magnetic cage?
3. Can this can of combustion be used in air-breading engines?
It’s possible that prototypes have already been flown and go all the way back to the 90’s this technology has been in the works for a long time now. But obviously actual information that goes in-depth to this technology is classified and everything spoken in this vid and any papers you can find on this are all generally basic overviews/theoretical underpinnings and have no information in regards to how to actually realize such an engine. Many things are hidden behind top secret or above top secret classifications like special access programs aka what are generally called black programs which even the president isn’t told about unless there is a need to know… the military and its biggest contractors are 10-30 years ahead in technologies across the board pretty much, and when you seen a leap forward in technology from the private sector it’s usually bc some technology has been allowed to become public knowledge bc they have something newer now…. This is how it has always worked
Does the engine create any angular momentum, if so would different modes affect the angular moment of the system?
I wonder instead of LOX if you could use something like Reaction Engines' heat exchanger while in atmo?
Detonation infers sos flame front propagation.
Can you explain the method how to prevent backflow of ignition products.
Hey there, my question would be, so I see a clarinet player making music, is there a way to get three of your friends to play an F Major chord? What would that look like in this engine?
Work for Pratt or GE Aerospace yet? Nice job.
have you considered simulating the radial? the real interesting questions are the limits of its stability.
What Thrust-to-weight ratio would be possible?
whats the benefit of this? changing the detonation speed to account for changes in pressure for efficient operation of a rocket? or so you dont have to have a cone to redirect flow?
How much can these engines be scaled down before the detonation wave stops propagating?
Do they have sweaters like this so they know which one they have on when they look in the mirror? :-)
Question: does the rotational nature of the detonation waves end up inducing a reactionary torque on the device? Just curious in the context of using this in a rocket engine.
Not as long as it is only the wave-front that is traveling around - there is no actual radial movement.
There is an engineering adage in manufacturing - "if you can't fix it, feature it".
Are these engines powerful enough to be used as first stage engines? Is STTO feasible with it?
My understanding is it's not really discussing the POWER of rocket engines, but more a new method of analyzing the thermoacoustic STABILITY of them. Rocket engines have a habit of tearing themselves apart if the shock waves bounce around too much, so you can use this method to tune injector plates/nozzles/baffles to create this dynamically stable state that seems to have negative feedback dynamics to return to stability.
@@killerguppy2988 Rocket engines (and all engines to date) burn their fuel subsonically. It only flows supersonically after passing through the throat. This is a whole new beast.
I have a lot of reading to do on these, but it sounds like the propellant can be injected at much lower pressure than in a conventional rocket. This is because the detonation itself compresses the propellant. That means you can use much lighter pumps. I'll be surprised if they can get the power density as high as conventional rockets though. I'm guessing the combustion chamber will have to be pretty stout to survive this cycle.
So far - no, not even close. Due to the complexity to just design them, the time to test and amount of work to simulate and analyse them we are basically at the start of the research-cycle. We do not even know if they are able to become as powerful as a convetional engine.
But that also is not the focus of the research nor the goal to achieve either.
Felt like Homer Simpson watching this video! LOL Interesting as hell, but in over my head.
Sounds like timing issue. Try using a transducer for a sensor to detect the shock wave then modify fuel and air as needed to stabilize. Also you may want to consider a mechanical intake like a nose cone on a SR-71 blackbird.
Intake isn’t the issue with the set ups they are using (they aren’t air breathing)
@@metatron5199 I didnt write this for this video
It's like Tony Stark was cosplaying this dude... Real life science is awesome!!!
I feel I could make a smaller model of this engine (outer nozzle diameter of about an inch) using some common materials you could get at a hardware store. I feel a lot of this long winded stuff scares most people from attempting such an experiment for themselves but from what I’ve seen from different models makes me feel making one isn’t too complex or challenging. The only difficult thing is getting the flame front to turn into a detonation wave that travels around the circumference, and that could probably be fixed by turning it on and off a few times till you finally get the result you want, it seems that’s what every other institute does so I don’t see how anyone could literally make this in their backyard or shed and have it function
You must be misunderstanding the force of a detontation wave. You can go to the hardware store and make a rotating pulse jet engine that has deflagration combustion at about 1 meter/ second. Which generates a mild pressure wave pulse of only a few psi to maybe 50 if constructed properly. When you go from deflag ( subsonsic combustion) to detonation supersonic)you are dealing with 1000s × amplification. So unless you are willing to have all your fitti gs, couplings and wall thicknesses, not to mention welds, handle 10 to 50,000 psi or more pressure waves which pulse thousands of times per minute and combust at supersonic speeds than stick to a hardware store pulsejet. Or get a good life insurance plan.
Well that's rocket science!
Thinking about this further. Sounds like a timing issue, try three spark plugs with three sensors for advancement of your timing to keep your chain reaction going. I would align the sensors and spark plugs in a hexagon pattern. Like a distributor cap on a car engine.
Could you kick up the 4d3d3d3?
This is a gamechanger and I can tell he knows it himself!!! Great job!!! You should call SpaceX and the new Space Force!!! I am not sure people realise what this means to the upcoming space race!!! China and other American competitors are paying attention I am sure! This is IP that is very important to America!!! I hope everyone understands how significant this progress is???
In the 1950's they were trying this... The exciting part about this is we can see it working now!!! Amazing work!!! If you don't know what this engine can do you must understand first how much is wasted and lost from current rocket engines!!!!!!!!!
19:20 Where else would it be if not at 42?=) The ultimate answer
I think I hear clipping from the over-amplified microphone.
In theory.., if a Theorist goes near it will stop working.
So by Observation, quantization cause-effect of spin-spiral phase-locked conic-cyclonic expansion wave-packaging formation is "inexplicable" log-antilog interference positioning-location, as when a Tornado sheds fractal vortices..?
Amateur guess.
Very interesting presentation.
It really needs to be a tall combustion so that it has a 100% detonation at the Nozzle
Isn't the term 'nonlinear dynamics' somewhat redundant?
Not at all. Just do some basic google searches for linear dynamics and then nonlinear dynamics. Two very different things.
Layman's terms please!
University of Washinton huh...good to know Blue Origin are funding interesting work.
"Boeing Department of Aeronautics and Astronautics"
This is an excellent and highly interesting presentation,
but if you're going to mirror the picture don't wear a sweater with text on it.
Unimpressed with only 150 seconds of Specific Impulse in vacuum. NERVA from 1966 had 10x that specific impulse in vacuum.
I get bad (re)flux from (eating too many) burgers as well.
All of this to predict how to build an F-1 size engine with a low probability of spontaneous rapid disassembly.
I understood most of that. What am I doing with my life..
Paul Rudd knows its shit.
increase number of waves by increasing path length. Use switchback curves around the perimeter of the circle to effectively do this without increasing size
4 names starting with K, it's fate
I just know that this guy 5 years ago was the complete antithesis to the guy speaking in this video lmao.
This is probably a very good presentation for engineers who are already familiar with rotating detonation engine dynamics, but he doesn't explain what he is talking about. He shows a picture of heat and pressure gradients without explaining what we are looking at. Scott Manley's video was far clearer and aimed at everyone without assuming we are all DTE engineers!
Because this video is presenting an already tested idea about how to calculate this behaviour, once other experts work on the model it might become good enough to use in engineering design of new engines, that may (or may not) be better than current deflagration engines.
However right now, this video is merely for those who can help improve and refine the theory in the hope of benefitting future generations of humanity.
Now put this Technology into an lighter.
Why is the video reversed?
This video has attracted kind of an oddball audience. This is not some “science video”, it’s effectively the presentation component of a doctoral defense. Dr. Koch is shown presenting the topic of his dissertation completed last year (when this video was posted), which is the title of the talk. That’s it. It’s understandable for the general, educated public to not recognize the norms of professional academic research, including the people who are “blown away even though” they have a BSci in engineering or physics. But the people trying to pick apart his “vocab” etc. either for understanding or for critique are way off-base. Knowing what “radial” means does not bring you close to understanding a normal PhD defense in aeronautics. Yes, there’s nothing abnormal or abnormally prodigious about this talk, but getting a research PhD in a field is a pretty big deal, and now I guess more people know why. Now you know how far a Bachelor’s and even a Master’s are from a completed PhD in a discipline. As of 2021 Koch is a postdoc in Texas. In other words, “not even” a professor yet. And it may be a few years still, of even more research, more publications, more grants, etc. before someone like Dr. Koch is offered a tenure-track position (if he wants to stay in academia, vs. industry) at a university. So now you know how far away all of your professors were from you in basically every uni class you’ve been in (albeit not all classes are taught by professors per se). Anyway, as a rule, dissertations contain much better explanations of the principal research than the overly brief papers based on them (as linked in the description), so here is Koch’s actual thesis: digital.lib.washington.edu/researchworks/bitstream/handle/1773/45431/Koch_washington_0250E_21238.pdf?sequence=1&isAllowed=y
I am sure the printing company totally mirrors their prints on every clothes they make and you didn't mirror the video in post...
i think the problem is the resonace
Rotating Detonation is like the Wankel engine of rockets. Hopefully long burn duration combustion stability can be achieved in real world testing.
When can we expect CCP to implement your research?
Loading....
Phew words
The S is sizzling ... :-( maybe a better microphone ?
BS
Im sure if he keeps speaking long enough... that he may get this theoretical, 40 year old idea to work on a flawed computer model … but in practicality ? which does not follow the flawed models … highly doubtful you can sustain the detonation for a sufficient / efficient amount of time.
I get what he saying for the most part, but for presentation purposes, ya gotta dumb it down. Could have explain it in half the time with layman terms.
Great scientific knowledge but you need to speak without technical terms
I'm not a scientist , I'm not an engineer
Your 7th grade math teacher should have covered all of this...
My guess is you are probably not his intended audience.
This is still technical but may be more accessible, informative, and useful for you -
_What Is A Rotating Detonation Engine - And Why Are They Better Than Regular Engines - Scott Manley_
ua-cam.com/video/rG_Eh0J_4_s/v-deo.html
Speak to you audience. Few of us have PHDs. Many don't have masters. Some have bachelors w/ post grad studies. Loose the big words, talk to us on OUR terms, you've failed!