Precisely! Completely agree 👍🏾 there is far too many people just using CLICK BAIT clips to get us to watch, It's beginning to annoy me that so many people ask you to hit the thumbs-up button and press bell for notifications at the very beginning of a video! This guy waited till the end which I respect a lot. A massive 👍🏾 from me, thank you.
very well explained video especially interesting the extra lift to the wings provided by the placing of the motor and the effect of the vortex to help lift under the wing
What is the glide ratio when the power cuts out? How do you steer when the power cuts out? How does it auto rotate when the power cuts out? So many engineering challenges beyond slapping a battery and few dozen motors together. this will never be certified part 91 or 135. Looks cool though.
It looks as though it will have the glide ratio of a wing suit. I'm not sure about the controls though - will they be of any use without the ducted fans?
Now this is how you present complex ideas! Fabulously clear in structure, articulation and presentation. As a management consultant of many years and a veteran of trying to present complex ideas in a digestible form, I absolutely love your approach here. As an engineer and pilot, it's pure gold. Instant sub and many thanks for your efforts - cheers from Sydney, Aust - Dave
@@ElectricAviation Thank you but as my children will attest, I am a tough critic. You have such wonderful clarity of thinking and expression that I would happily enjoy you describing grass growing or the ubiquitous paint drying process! I have had many years of McKinsey based training and am a proponent of Barbara Minto's teaching of thought structure (the "Pyramid Principle"). It's rare to encounter such beautifully clarified information and I am truly in awe and am enjoying your videos immensely. Regards and thank you - David
In terms of battery consumption. The first obvious benefit Lilium Jet has over its competition are Wings. Much of the battery drain happens during the hover phases of vertical lift and landing. But where the competitions calculations are off in regards to lilium, is that their wingless drone like concepts are always in a state of lift via their engines, constantly operating at high output just to stay aloft. And they use large electric motors in comparison to Liliums many small electric ducted fans. Also there motors are accompanied by large fully exposed rotors , which take a lot of power to generate lift, also making them very noisy like a leaf blower from hell. Lilium on the other hand uses 36 small electric ducted fans that dont require a ton of energy to operate at full speed, Their size do operate at higher rpm's for VTOL than the competition, which usually would equate to heavy noise, but due to ducted fan design they not only move a ton of air for their size but also are no where near as loud. And since theyre many engines around the aircraft flight surfaces, lift is generate far more efficiently than the competition. in fact, due to the location of its engines along the surface of the wing it combines both engine produced lift as well conventional air pressure induced lift from the wings airfoil, as engines drive wind over the wings at high speeds. Effectively adding to the force of lift and overall requiring far less energy. There is so much simplicity in its design yet is design is pure genius. What initially looks rather odd with all the multi engines, only takes a skilled and learned mind to realize the brilliance overall. A true leap in aviation design. Aside from the fans, themselves their are so few moving parts, and yet, liliums design combines flight characteristics that of both winged aircraft and that of Helicopter/drones, but goes far beyond due to its propulsion control, and configurable in flight layout. When you look at lilium jet , it looks like the future, it looks as if its a design born of years of innovation. But remarkably they team behind its creation, nailed it from the start. A group of young adults that were not even primarily into aviation. And just out of the gate hit on a brilliant design like no other. looking at the competition from Boeing Uber Airbus , its all the same.. either some scaled up done concept, or something that is attempting to mimic liliums design but cant since they cant breech patent laws. And oh yes they all had drone designs at first, then after seeing lilium tried to incorporate some its design layout into theirs. And their concepts can fly, but they are heavy in electrical consumption and extreme drag. Where as the lilium jets full design is a drag resistant lift to drag ratio of 21 to 1, as the fuselage itself creates lift. None of the competitions design come anywhere near as close. Which is why Lilium jet can achieve its claims. True Genius and Brilliance in its design throughout.
@@emotodude Well again, there's alota factors to that debate. are electric engines more efficient than combustion? its a hard question, because you may ask do cities run on electracy? yes but no. because most cities are powered by either Nuclear, hydro electric (water turning turbines producing electricity) or diesel. in the end its a mixture. Problem with big rotors is big noise, and a higher threshold of danger. Where as Lilium's ducted fans pose virtually no threat in regards to personnel proximity. you'd literally have to shove your fingers inside their engine pods to hurt yourself, which means operations wise, the Lilium jet will be first out the gate in regards to passing safety regulations and requirements. Many of those other drones design see their rotors open and exposed and notably, would need to fully shut down entirely before passengers could enter and exit the vehicle, thus dramatically slowing operations. This doesn't even occur with helicopters, which does have large exposed rotors, but are situated very high above passengers and operators. So operational delays wouldn't need to occur with lilium, possibly not even for Airbus overhead rotor concept. Now i would say one thing about that airbus, bus design. Loud, yes, BUT it will serve far more passengers than lilium. And although not as advance as lilium , i see it as that step in-between traditional helicopters and something like lilium jet.
@@xevious2501 Current battery technology is incapable of providing even 20% of the energy density of fuels. Small EDF motors are MUCH less efficient than large props, the claims of long range AND performance for this design are total bullshit. It isnt a hard question to answer if electric "engines" are more efficient than combustion. Lithium sulfer doubles the energy density of lithium ion, and still isnt enough to make sense for aircraft even of traditional design compared to fuels, meaning the thing is probably capable of lifting its own weight of frame and electronics/battery/motors/ESC/ect. and puttering around with no real performance for 10-12 minutes, with NO PASSENGER. Exactly what you see in the video.
What have you been smoking? You sound like a guy from their marketing team! Only because engines are tinier and ducted does not mean that the airflow is higher, only the rpms and the noise is increasing to compensate for the lack of blade surface and efficiency. Until today they have been unable to do any non hover flight even with an empty aircraft! They are in a dead end road with that concept in the near future.
No nonsense title attracted me to this video, thanks for producing this. This is one of the few, if not one of the only, videos outside of Lilium's official channel that provides some semblance of thought and insight.
One of the big advantages of this design is: The distributed fans along the wing support the function of the wing even at very low speed by preventing the wing from stalling. So even at low forward speed you get extra lift from the wings. The high power consumption during vertical take off is therefore reduced dramatically after the airplane begin to move forward while still not flying with cruising speed.
There are tons of disinformation shills are just naysaying about this vehicle without good regard of this fact. I could pick a few right off of the top comments.
@@SouthernHerdsman I would say people naysaying arre not shills. It far more likely for promoters of it to be sellout. Especially when the company raises more red flags than what you can see during a parade on the red square in moscov. Labeling ducted fan a e-"jet". Labeling CGI as testing videos. Claiming protottype was tested to fly with human, then showing video of it flying empty as evidence. Then prototype burns down under mysterious circumstances in middle of COIVD-19 pandemic, when media is focused elsewhere. To say the least, its giving pretty strong Theranos vibes.
This is exactly what he says in this video at the end when he says don't think of it as VTOL, but instead as a system of propulsion and lift together in one that have created an aircraft with such exceptionally low stall speeds that it essentially behaves like a traditional VTOL
Awesome video.The only thing holding these beautiful electric aviation designs back is the lack of a groundbreaking new low weight, high storage battery technology that can match or exceed the thrust, weight and flight duration performance of traditional fuel and engines.
I'd think a hybrid storage system of fuel cells with super capacitors could have a verry good energy to weight ratio as well as a good power to weight ratio, assuming high power is only requiered for short amounts of time during a flight. Hydrogen tanks have a verry good energy to weight ratio (even better than fossile fuels). Hydrogen fuel cells struggle with high power compared to their weight similar to batteries though. This would be the application of the capacitors wich have a verry good power/weight ratio. I imagine the fuel cell being used for cruising with the capacitors adding power for takeoff. The capacitors would be recharged slowely by the fuel cell when on the ground or even (verry slowely) while cruising.
At work a group of us with experience designing helicopters and powered lift STOL aircraft came to a very similar conclusion with regard to the coupling of the flow of the propulsors and the wings. One thing we noticed in the video of the take-off of the prototype is that the thrust vector of the front lift propulsors (which in the prototype are pure thrust rather than thrust/lift canard as in the final version) was slightly towards the rear as the vehicle lifted off. This would imply that the main wing and propulsors was generating a small amount of axial force that needed to canceled by a small amount of rearward thrust by the front propulsors. This could be important because it has the potential to mean that the main wing propulsors are not quite vertical at take-off, but instead are pitched a few degrees forward. Even a few degrees would mean that more of the air being drawn into the propulsor would come over the top of wing. Thus a substantial portion of the total lift required could be coming from the wing. The vertical portion of the total thrust from the thruster is the cosine of the angle to the vertical. So a forward pitch of 5 degrees would only mean that the vertical component would 99.6% of the total propulsor thrust. 10 degrees would be 98.5%. So for a 1.5% loss in thrust lift, the flow over the wing and thus aerodynamic lift could be greatly enhanced. That would completely change the power calculation from a purely propulsive lift. In the December 18, 2019 video of the flight of the final version with propulsors on a canard we could see right at landing the propulsors on the canard went past vertical to provide braking thrust to stop the forward motion of the vehicle. That means that the final version with the canard has the same ability at take-off to point the canard propulsors rearward to cancel out forward thrust from the main propulsors. And last note, the lilium will make a terrific "super-STOL" vehicle that will require half or less of the power of a fully vertical take-off or landing when there is an opportunity to have a short ground roll and a non-vertical climb-out or landging. Due to the strong circulation, as you say, the wing would never stall. I have seen wings with a lot of upper surface suction where the stagnation point is in the middle of the bottom surface with streamlines flowing forward from the stagnation point, hooking sharply around the leading edge and flowing with greatly reduced static pressure into the propulsors. This allows departure and approach angles to be in the 30+ degree range. So even without a purely vertical take-off the vehicle will be able to clear a 50 foot obstacle within 50 to 100 ft of the lift off/landing point. It will also mean that any parking lot (car park) could serve as an emergency landing strip should the batteries get to a state of charge where they can't make enough power to do a vertical landing.
placing the engine input right above the top of the wing at the back is something I've been wondering why it hasn't been done. good work for seeing the future.
Bravo. I wish you would have been my physics professor back in highschool. You make everything very clear to understand. This is how you make an explanation video. And a great piece of engineering deserves a great explanation.
I realize this is a cuss word to most electric powered engineers, but why couldn't a hybrid example work for this awesome craft? A small 2000 watt generator to kick in for take off and landing, or if the battery reaches a critically low level. My camping generator weights 27 lbs, so weight shouldn't be that much of an issue. Just like some of the early electric cars carried a small gas engine to assist with steep inclines, or needed boosts. Its like always having a back up battery on board, just in case.
The crazy thing about the Lilium patent is that, after looking at the practical application, it's really not complicated. Someone just added the simplicity of the airfoil design and the placement of the small ducted fans in relationship to the airfoils. A little Venturi is also implied with regards to the bottom of the airfoil on VTOL lift-off. Great video.
it’s unfortunate as it means no competitor can make an aircraft that puts ducted fans along the wing, even if the rest of the aircraft’s configuration is completely different :(
A cable supplying power during liftoff is additional weight to lift. It would consume more benefit than it would deliver. Even a system of microwave power transmission would require additional aircraft weight to receive and manage the power while also complicating the aerodynamic lifting body shape.
This though had occurred to me also, surely the most power is drained in the initial stage of vertical takeoff, a tether with its own powered flight to make it zero weight gain could work to assist this first stage
@@douglaseddy1960 I had the same idea. 10m poles who supports the energy consumption at take of. These drones are anyway only meant for flying from point a-b.
Thankyou for covering some of the technical aspects. There is a huge elephant in the room though. Lilium have consistently failed to get anywhere near the performance and timeline they announced with so much hype. Back in 2016, these things were going to be available to buy in 2018, with 500km range and 400kph cruise. Pure fantasy. Here we are 5 years later and a model is managing minutes long flights around their airfield. And yet each failure to deliver is simpy brushed aside with some incredible new hype and new in service date. It is a peprtetual 4 years away. But they seem very proud of being on their 5th generation of 'prototype'. Just one problem, none of the previous 4 have come anywhere near demonstrating the performance being hyped. I can see they have worked through some of the necessary innovations but what they have right now is nothing more than a big model making tiny little flights around their airfield, when what had been promised was a passenger carrying service date that was already missed 3 years ago. With the company being floated this now has all the hallmarks of another Theranos - bold claims but nothing tangible except some expensive mock-ups and a flying model that has demonstrated none of the performance claimed.
I agree with most of what you have written. This video was made a while back. I think they are just waiting for the battery technology to catch up. If not they can either go for fuel cell or a Electrical generator. I would still like them to show a VTOL flight with even sandbags so that they can demonstrate with weight.
@Electric Aviation yes, and I am not denying they have some innovations in the aerodynamics and propulsion. But their claim is to deliver all this performance into service with batteries and be certified by 2024. The company was not floated on the proposition of investment in a perpetual flying testbed with fuel cells as the next project. Bottom line is after 4 years flying models they have not made a single flight that demonstrates they are anywhere near being able to deliver on their fantasy claims for range, speed and payload. Instead of answering skepticism with verifiable information they just reply with defensive PR rhetoric. Thankyou for your reply and your video analysis of these projects.
Amazing breakdown. Excited to hear more on coming projects. The last prototype catched fire 🔥 in the beginning of the year but I think they actually have a leadijg position here and are very secretive. Who do you see leading?
I was a supporter of the Lilium from it's beginning as I still am today but I could not work out how it managed to fly...that was until now 😳👍👍👍 This video has been superb knowledge for me, many many thanks for making it.
I think a fixed wing with rotating ducted electric turbines like this is perhaps the best overall design concept. Love it! This kind of design can take off vertically or with a runway to save energy too and has no large propellers that could be dangerous.
Fantastic video man! Keep it up! There is so much nonsense out there around these topics and its great to see find a channel that reports based on analysis.
Excellent explanation. I was thinking I might try to build an RC model but the expense of so many smaller EDFs would be too expensive. If I go with a VTOL, it will have to be with a tilt-wing using only 4-8 motors.
You can get the small EDFs for low price. Its the larger ones that come at a premium. So depending upon how big your model would be, it can cost exponentially higher
@@ElectricAviation I recently bought 2 counter rotating, 1 CW and 1 CCW, 70mm EDFs (6S voltages) at a cost of about $45 each. They haven't flown yet, but I hope they will soon. They are in my first scratch-built EDF jet, an SR-71 Blackbird. But the weight may be too high, 9lbs empty. We'll soon see. EDIT: Sept 2021 It did fly but more work is needed. It's definitely not a VSTOL, although my landing would seem to indicate that. ruclips.net/video/PThsS5iXwnI/видео.html
hey, thanks for your analysis; I could be wrong about this; but when the "fan surface" is in the vertical orientation or nearly so and is moving forward ; I believe that the overall shape of the airfoil that is created by this configuration is acting essentially as "full span" flaps. Thereby greatly increasing lift and lowering stall speed.
A couple technical comments to this nice video. Impressive the L/D ratio of 21 for such a small wing aspect ratio! With this in mind the vertical take off and landing, even if high power (and energy consumption) have a short duration (1 minute each?) as the plane will transition soon to fixed wing flying in which it will stay most of the time (60 minutes) to achieve the 300 km range. It makes sense to me!
Great work, one question. What would be the consequences of turning off the EDF during flight, will the air resistance across the free rotating blades cause a stall?
I think the consequences would be dire. Like having full wing spoilers. You'd have to dive steeply to maintain enough airspeed to keep it behaving like a plane.
Flight safety in takeoff and landing is always a concern. A full power loss depending on speed and altitude could be a problem. Redundancy may be needed. A simple parachute system could be implemented. The video presentation shows detail system knowledge and excellent integration. In the design space like to see where battery density plays into the design and what was used for range estimates / speed estimates. Otherwise excellent engineering and design choices.
@@caddymj Speed and altitude with total power loss are inconsequential (unless both are 0) being as that there are no control surfaces. No mater what the airspeed and altitude the pilot is now a passenger.
Since VTO consumes 10X more energy, the solution is painfully obvious, and it's surprising no one has fixed this yet: Simply have a quick and automatic release power tether that pulls off once the craft is airborne. Maybe give it a 10 to 20 yard length so once the plane gets underway, the forward momentum alone will disconnect the ground power. Then have a cable boy/girl run out and spool it back into the landing zone. Basically, take offs will consume ground power, keeping batteries topped off at full until aerodynamic lift is achieved, or is more inexpensively achieved. The cable length could be adjusted depending on weight considerations, but remember, the power usage would be irrelevant until the cable disconnects at which point the cable weight would be irrelevant.
Just have to engineer a way to control the cable so it doesn't get sucked up and FOD out an engine...otherwise, you're right that is a elegant solution!
@@detour1055 Why would the cable get sucked up? By definition it would be on the exhaust side and would naturally be blown away from the aircraft. As the aircraft rises, cable would be blown downward naturally. Just ensure it's spooled so there's not a lot of loose cable laying around which then could possibly be thrown around with the ground turbulence. But even then the energy that could be imparted to the cable is not likely to be able to throw it above the aircraft into the intakes, esp. since the weight of the cable is always pulling it downward.
@@detour1055 (Also, assisted takeoff and landings are nothing new, the military has been using it on aircraft carriers since the first carriers existed, - although in the old days take-off assists were mechanical, like catapults. Tailhooks and cables I think are still in use for landing assists. This would just be a different kind of take-off assist)
So good even an electrical engineer can understand it. Although, I flew hang gliders for 12 years so I might have some knowledge beyond my formal education.
Excellent and very informing. Looks like you have a lot of potential. Perhaps in the future you might also give performance numbers and weights in both Metric and inch/feet/pounds, since in order to really appreciate the numbers, I had to bring up a conversion table and stop the video several times to convert the numbers into terms my 75 year old brain is familiar with. Thank you!
Very good explanation, but you didn't cover the main reason these types of aircraft will not be commercially viable... i.e. instability during an engine out event... e.g. if one ducted fan fails during take-off or landing, it will cause instability and roll. To counter an engine out, the opposing fans must either decrease their thrust, or fans on the same side as fan out, increase their thrust. If you decrease the oppposite thrust then you decrease overall lift by 19kgf x 2 = 38kgf, and therefore be unable to maintain lift. If you wish to increase the thrust on the same side as engine out, the electric motors must be able to increase their output by over 38% which they will not be able to do. Therefore these type of aircraft will not be commercially viable... lots of prototypes... but no successful commercial production...
I am maths challenged but all that made perfect sense to me. What a fascinating vehicle. Like something out of the sci fi of my youth. Gerry Anderson would have kittens!
Academic !!! I wish you had elaborated on the transition mode and issues arising in such phase. The remark as to the fact that this aircraft may be considered as one having a very low stall speed rather than an eVTOL alludes to one aspect which may be related. Also, you mentioned EDF diameter vs Power Consumption and vs specific thrust. It would be interesting to hear your thoughts on how Lilium may have determined the sweet spot. Also, they had in the earlier design a sort of rotating cylinder housing a couple of EDFs in lieu of the current Canard, it would be interesting to hear your thoughts on this change and the tradeoff associated.
Ok, lets crunch some numbers! First - nice analysis of required t/o power! But the main challenge in these numbers is the numbers itself: Energy density! Aircraft gross weight 440Kg with a 320kwh pack? Even if that was just for the battery pack that would mean an energy density of 720wh/kg on pack level. That's easily double the max energy density that current lithium ion accus can provide even on cell level. That being said, the given weight figure is for the whole aircraft! The video mentions that one single of-the-shelf 195mm EDF has weight of 3,4Kg while the a/c actually uses 36 larger 250mm EDFs. So these 36 EDFs alone make up for at least 120Kg of the aircraft weight. To get an even number, lets estimate another 80Kg for the airframe structure, seats, electronics, wheel base, everything else: So the a/c weight without battery would be around 200kg. Only 240kg would be left for the battery pack. So to achieve 440Kg gross weight with an 320kwh battery, the required energy density would be around 1.3kwh/kg on the pack level. That's currently impossible and will remain so for quite some time. Only a rough estimation, but with the numbers given in this video, it's somewhere in this ballpark . Maybe these goals are set far out and they try to start with a smaller battery? Achieving 440Kg gross weight even with a 100kwh battery would still be extremely challenging today.
Man, I really appreciate a straightforward, gimmick-free, explanatory engineering video.
I came here to say exactly that!
Precisely! Completely agree 👍🏾 there is far too many people just using CLICK BAIT clips to get us to watch, It's beginning to annoy me that so many people ask you to hit the thumbs-up button and press bell for notifications at the very beginning of a video! This guy waited till the end which I respect a lot.
A massive 👍🏾 from me, thank you.
👏🙏
Great engineering explained simply without bad music, bad humor and clickbaiting 👍🏽
Just tons of misinformation!
@@emotodude Would you care to elaborate?
@@emotodude What is the misinformation? Or do you work for a competitor?
very well explained video especially interesting the extra lift to the wings provided by the placing of the motor and the effect of the vortex to help lift under the wing
Thank you
What is the glide ratio when the power cuts out? How do you steer when the power cuts out? How does it auto rotate when the power cuts out? So many engineering challenges beyond slapping a battery and few dozen motors together. this will never be certified part 91 or 135. Looks cool though.
It looks as though it will have the glide ratio of a wing suit. I'm not sure about the controls though - will they be of any use without the ducted fans?
@@dudeskidaddy When they loose electric power, the Lilian Jet is not controllable anymore and you better have a parachute rescue system installed.
Now this is how you present complex ideas! Fabulously clear in structure, articulation and presentation. As a management consultant of many years and a veteran of trying to present complex ideas in a digestible form, I absolutely love your approach here. As an engineer and pilot, it's pure gold. Instant sub and many thanks for your efforts - cheers from Sydney, Aust - Dave
You are very kind
@@ElectricAviation Thank you but as my children will attest, I am a tough critic. You have such wonderful clarity of thinking and expression that I would happily enjoy you describing grass growing or the ubiquitous paint drying process! I have had many years of McKinsey based training and am a proponent of Barbara Minto's teaching of thought structure (the "Pyramid Principle"). It's rare to encounter such beautifully clarified information and I am truly in awe and am enjoying your videos immensely. Regards and thank you - David
In terms of battery consumption. The first obvious benefit Lilium Jet has over its competition are Wings. Much of the battery drain happens during the hover phases of vertical lift and landing. But where the competitions calculations are off in regards to lilium, is that their wingless drone like concepts are always in a state of lift via their engines, constantly operating at high output just to stay aloft. And they use large electric motors in comparison to Liliums many small electric ducted fans. Also there motors are accompanied by large fully exposed rotors , which take a lot of power to generate lift, also making them very noisy like a leaf blower from hell. Lilium on the other hand uses 36 small electric ducted fans that dont require a ton of energy to operate at full speed, Their size do operate at higher rpm's for VTOL than the competition, which usually would equate to heavy noise, but due to ducted fan design they not only move a ton of air for their size but also are no where near as loud. And since theyre many engines around the aircraft flight surfaces, lift is generate far more efficiently than the competition. in fact, due to the location of its engines along the surface of the wing it combines both engine produced lift as well conventional air pressure induced lift from the wings airfoil, as engines drive wind over the wings at high speeds. Effectively adding to the force of lift and overall requiring far less energy. There is so much simplicity in its design yet is design is pure genius. What initially looks rather odd with all the multi engines, only takes a skilled and learned mind to realize the brilliance overall. A true leap in aviation design. Aside from the fans, themselves their are so few moving parts, and yet, liliums design combines flight characteristics that of both winged aircraft and that of Helicopter/drones, but goes far beyond due to its propulsion control, and configurable in flight layout. When you look at lilium jet , it looks like the future, it looks as if its a design born of years of innovation. But remarkably they team behind its creation, nailed it from the start. A group of young adults that were not even primarily into aviation. And just out of the gate hit on a brilliant design like no other. looking at the competition from Boeing Uber Airbus , its all the same.. either some scaled up done concept, or something that is attempting to mimic liliums design but cant since they cant breech patent laws. And oh yes they all had drone designs at first, then after seeing lilium tried to incorporate some its design layout into theirs. And their concepts can fly, but they are heavy in electrical consumption and extreme drag. Where as the lilium jets full design is a drag resistant lift to drag ratio of 21 to 1, as the fuselage itself creates lift. None of the competitions design come anywhere near as close. Which is why Lilium jet can achieve its claims. True Genius and Brilliance in its design throughout.
Thank you for you insightful and informative comment
If you think many small fans are more efficient than few larger rotors you need to do some homework.
@@emotodude Well again, there's alota factors to that debate. are electric engines more efficient than combustion? its a hard question, because you may ask do cities run on electracy? yes but no. because most cities are powered by either Nuclear, hydro electric (water turning turbines producing electricity) or diesel. in the end its a mixture. Problem with big rotors is big noise, and a higher threshold of danger. Where as Lilium's ducted fans pose virtually no threat in regards to personnel proximity. you'd literally have to shove your fingers inside their engine pods to hurt yourself, which means operations wise, the Lilium jet will be first out the gate in regards to passing safety regulations and requirements. Many of those other drones design see their rotors open and exposed and notably, would need to fully shut down entirely before passengers could enter and exit the vehicle, thus dramatically slowing operations. This doesn't even occur with helicopters, which does have large exposed rotors, but are situated very high above passengers and operators. So operational delays wouldn't need to occur with lilium, possibly not even for Airbus overhead rotor concept. Now i would say one thing about that airbus, bus design. Loud, yes, BUT it will serve far more passengers than lilium. And although not as advance as lilium , i see it as that step in-between traditional helicopters and something like lilium jet.
@@xevious2501 Current battery technology is incapable of providing even 20% of the energy density of fuels. Small EDF motors are MUCH less efficient than large props, the claims of long range AND performance for this design are total bullshit. It isnt a hard question to answer if electric "engines" are more efficient than combustion. Lithium sulfer doubles the energy density of lithium ion, and still isnt enough to make sense for aircraft even of traditional design compared to fuels, meaning the thing is probably capable of lifting its own weight of frame and electronics/battery/motors/ESC/ect. and puttering around with no real performance for 10-12 minutes, with NO PASSENGER. Exactly what you see in the video.
What have you been smoking? You sound like a guy from their marketing team! Only because engines are tinier and ducted does not mean that the airflow is higher, only the rpms and the noise is increasing to compensate for the lack of blade surface and efficiency.
Until today they have been unable to do any non hover flight even with an empty aircraft! They are in a dead end road with that concept in the near future.
No nonsense title attracted me to this video, thanks for producing this. This is one of the few, if not one of the only, videos outside of Lilium's official channel that provides some semblance of thought and insight.
Love the physics, engineering and math talk
One of the big advantages of this design is: The distributed fans along the wing support the function of the wing even at very low speed by preventing the wing from stalling. So even at low forward speed you get extra lift from the wings. The high power consumption during vertical take off is therefore reduced dramatically after the airplane begin to move forward while still not flying with cruising speed.
There are tons of disinformation shills are just naysaying about this vehicle without good regard of this fact. I could pick a few right off of the top comments.
@@SouthernHerdsman
I would say people naysaying arre not shills.
It far more likely for promoters of it to be sellout.
Especially when the company raises more red flags than what you can see during a parade on the red square in moscov.
Labeling ducted fan a e-"jet".
Labeling CGI as testing videos.
Claiming protottype was tested to fly with human, then showing video of it flying empty as evidence.
Then prototype burns down under mysterious circumstances in middle of COIVD-19 pandemic, when media is focused elsewhere.
To say the least, its giving pretty strong Theranos vibes.
This is exactly what he says in this video at the end when he says don't think of it as VTOL, but instead as a system of propulsion and lift together in one that have created an aircraft with such exceptionally low stall speeds that it essentially behaves like a traditional VTOL
I'm a book keeper and you manage to explain it to me. Brilliant
VERY interesting video! You have made everthing nice and easy to understand, neat graphics too:) Really want a Lilium now!!!
Its a cool design and it does what no other aircraft has done before, this will be big.
Check out Ehang. They are five years ahead of everybody in this sector.
I highly doubt it, unless this is just a stepping stone for Airbus size planes
How beautiful are the lines and contours of this amazing craft.
First rate production. Kudo's for a most informative treatment of this unique aircraft.
Unique is the right assessment! Agree 100%
Your videos are easy to understand and much appreciated. No on else is covering this material/developments. Bravo!
Super competent presenter. No click-bait here.
Awesome video.The only thing holding these beautiful electric aviation designs back is the lack of a groundbreaking new low weight, high storage battery technology that can match or exceed the thrust, weight and flight duration performance of traditional fuel and engines.
I'd think a hybrid storage system of fuel cells with super capacitors could have a verry good energy to weight ratio as well as a good power to weight ratio, assuming high power is only requiered for short amounts of time during a flight. Hydrogen tanks have a verry good energy to weight ratio (even better than fossile fuels). Hydrogen fuel cells struggle with high power compared to their weight similar to batteries though. This would be the application of the capacitors wich have a verry good power/weight ratio. I imagine the fuel cell being used for cruising with the capacitors adding power for takeoff. The capacitors would be recharged slowely by the fuel cell when on the ground or even (verry slowely) while cruising.
Extremely well explained, thank you.
An excellent, scientific, straightforward video! Thank you for your very educational video!
At work a group of us with experience designing helicopters and powered lift STOL aircraft came to a very similar conclusion with regard to the coupling of the flow of the propulsors and the wings. One thing we noticed in the video of the take-off of the prototype is that the thrust vector of the front lift propulsors (which in the prototype are pure thrust rather than thrust/lift canard as in the final version) was slightly towards the rear as the vehicle lifted off. This would imply that the main wing and propulsors was generating a small amount of axial force that needed to canceled by a small amount of rearward thrust by the front propulsors.
This could be important because it has the potential to mean that the main wing propulsors are not quite vertical at take-off, but instead are pitched a few degrees forward. Even a few degrees would mean that more of the air being drawn into the propulsor would come over the top of wing. Thus a substantial portion of the total lift required could be coming from the wing. The vertical portion of the total thrust from the thruster is the cosine of the angle to the vertical. So a forward pitch of 5 degrees would only mean that the vertical component would 99.6% of the total propulsor thrust. 10 degrees would be 98.5%. So for a 1.5% loss in thrust lift, the flow over the wing and thus aerodynamic lift could be greatly enhanced. That would completely change the power calculation from a purely propulsive lift.
In the December 18, 2019 video of the flight of the final version with propulsors on a canard we could see right at landing the propulsors on the canard went past vertical to provide braking thrust to stop the forward motion of the vehicle. That means that the final version with the canard has the same ability at take-off to point the canard propulsors rearward to cancel out forward thrust from the main propulsors.
And last note, the lilium will make a terrific "super-STOL" vehicle that will require half or less of the power of a fully vertical take-off or landing when there is an opportunity to have a short ground roll and a non-vertical climb-out or landging. Due to the strong circulation, as you say, the wing would never stall. I have seen wings with a lot of upper surface suction where the stagnation point is in the middle of the bottom surface with streamlines flowing forward from the stagnation point, hooking sharply around the leading edge and flowing with greatly reduced static pressure into the propulsors. This allows departure and approach angles to be in the 30+ degree range. So even without a purely vertical take-off the vehicle will be able to clear a 50 foot obstacle within 50 to 100 ft of the lift off/landing point. It will also mean that any parking lot (car park) could serve as an emergency landing strip should the batteries get to a state of charge where they can't make enough power to do a vertical landing.
placing the engine input right above the top of the wing at the back is something I've been wondering why it hasn't been done. good work for seeing the future.
"wondering why it hasn't been done":
Custer Channelwing - 1940s
Great channel, your ability to clearly explain the principles is very good indeed. I learned something today. Cheers
Bravo. I wish you would have been my physics professor back in highschool. You make everything very clear to understand.
This is how you make an explanation video. And a great piece of engineering deserves a great explanation.
this is one of my favorite designs. I like the way the rotas are hidden in the wings it makes it clean and stylish
As the design/production of the Lilium plane...the quality/clarity of this video - the same: EXCELLENT
I realize this is a cuss word to most electric powered engineers, but why couldn't a hybrid example work for this awesome craft? A small 2000 watt generator to kick in for take off and landing, or if the battery reaches a critically low level. My camping generator weights 27 lbs, so weight shouldn't be that much of an issue. Just like some of the early electric cars carried a small gas engine to assist with steep inclines, or needed boosts. Its like always having a back up battery on board, just in case.
You are very right. There are companies looking to do this. Range Extenders will be added to the aircrafts as their operating envelope gets bigger
Brilliant design and a brilliant presentation. Now I understand the subtitles of this very clever design.
Well done. thank you for the easy to understand explanation.
The crazy thing about the Lilium patent is that, after looking at the practical application, it's really not complicated. Someone just added the simplicity of the airfoil design and the placement of the small ducted fans in relationship to the airfoils. A little Venturi is also implied with regards to the bottom of the airfoil on VTOL lift-off. Great video.
it’s unfortunate as it means no competitor can make an aircraft that puts ducted fans along the wing, even if the rest of the aircraft’s configuration is completely different :(
Thanks for a so clear to understand explanation. Prosperity.
Once u get past the indian accent u realise this guy knows his stuff and explains everything really well
On Utube I have to adjust my ear to most of the narrators. Yes, this guy is all business, no fluff.
I've worked with so many smart Indian men and women that the accent automatically lends credibility. :0)
This gentleman has excellent English but it's the quality and structure of his message that really shines here. Truly wonderful.
If you want to go to the moon, you need guy like him ...... A mind is a terrible thing to loss ......
Be willing to bet his English is 1,000% better than your Hindi will ever be. Unsure why you needed to "get passed it".
Really enjoy the technical details and engineering discussion in your videos. Thank you.
Explained well and understood easily.
Couldn't they employ a long tether that supplies power during vertical takeoff?
A cable supplying power during liftoff is additional weight to lift. It would consume more benefit than it would deliver. Even a system of microwave power transmission would require additional aircraft weight to receive and manage the power while also complicating the aerodynamic lifting body shape.
Add a cable lifting drone or a ground based cable lifting arm?
This though had occurred to me also, surely the most power is drained in the initial stage of vertical takeoff, a tether with its own powered flight to make it zero weight gain could work to assist this first stage
I think they used the KISS principal. The vertical take off portion of flight is kept to a minimum.
@@douglaseddy1960 I had the same idea. 10m poles who supports the energy consumption at take of. These drones are anyway only meant for flying from point a-b.
Excellent video! I Learned a ton about my favorite evtol. THANK YOU 🙏🏻
Excellent rundown... enlightening! Thank you.
Glad you enjoyed it!
Пока что это лучший вариант гражданского электро-VTOL. Очень радуют его успехи. С нетерпением жду начала коммерческой эксплуатаци
Great video and very informative. Thanks from Australia :)
Thankyou for covering some of the technical aspects. There is a huge elephant in the room though. Lilium have consistently failed to get anywhere near the performance and timeline they announced with so much hype. Back in 2016, these things were going to be available to buy in 2018, with 500km range and 400kph cruise. Pure fantasy. Here we are 5 years later and a model is managing minutes long flights around their airfield. And yet each failure to deliver is simpy brushed aside with some incredible new hype and new in service date. It is a peprtetual 4 years away. But they seem very proud of being on their 5th generation of 'prototype'. Just one problem, none of the previous 4 have come anywhere near demonstrating the performance being hyped. I can see they have worked through some of the necessary innovations but what they have right now is nothing more than a big model making tiny little flights around their airfield, when what had been promised was a passenger carrying service date that was already missed 3 years ago. With the company being floated this now has all the hallmarks of another Theranos - bold claims but nothing tangible except some expensive mock-ups and a flying model that has demonstrated none of the performance claimed.
I agree with most of what you have written. This video was made a while back. I think they are just waiting for the battery technology to catch up. If not they can either go for fuel cell or a Electrical generator. I would still like them to show a VTOL flight with even sandbags so that they can demonstrate with weight.
@Electric Aviation yes, and I am not denying they have some innovations in the aerodynamics and propulsion. But their claim is to deliver all this performance into service with batteries and be certified by 2024. The company was not floated on the proposition of investment in a perpetual flying testbed with fuel cells as the next project. Bottom line is after 4 years flying models they have not made a single flight that demonstrates they are anywhere near being able to deliver on their fantasy claims for range, speed and payload. Instead of answering skepticism with verifiable information they just reply with defensive PR rhetoric.
Thankyou for your reply and your video analysis of these projects.
Loved your video as a long term supporter of lillium it was good to have that broken down!
Very good explanation! Thank you!
very good explanation and presentation. well done
Amazing breakdown. Excited to hear more on coming projects. The last prototype catched fire 🔥 in the beginning of the year but I think they actually have a leadijg position here and are very secretive. Who do you see leading?
Excellent engineering. First aircraft ever to fly backwards.
Not a wasted or second. New sub
Great job with your videos!!
Technology will resolve most of our Climate related issues... Big Ups to our Amazing Engineers!
I was a supporter of the Lilium from it's beginning as I still am today but I could not work out how it managed to fly...that was until now 😳👍👍👍
This video has been superb knowledge for me, many many thanks for making it.
ohhhh...so it's like the equivalent of torque vectoring in cars but in aircraft...BRILLIANT!
Nice explanation 😁
Looks like a modern design on the wright brothers airplane.
I think a fixed wing with rotating ducted electric turbines like this is perhaps the best overall design concept. Love it! This kind of design can take off vertically or with a runway to save energy too and has no large propellers that could be dangerous.
Keep it up. Explanation was as good as they come.
Well explained. Thanks.
Your videos are brilliant, thanks for sharing
Glad you like them!
Impressive explanation 👏👏👏👏👏👏
Excellent explanation of the principal design features. Look forward to more videos!
Fantastic video man! Keep it up! There is so much nonsense out there around these topics and its great to see find a channel that reports based on analysis.
Excellent explanation. I was thinking I might try to build an RC model but the expense of so many smaller EDFs would be too expensive. If I go with a VTOL, it will have to be with a tilt-wing using only 4-8 motors.
You can get the small EDFs for low price. Its the larger ones that come at a premium. So depending upon how big your model would be, it can cost exponentially higher
@@ElectricAviation I recently bought 2 counter rotating, 1 CW and 1 CCW, 70mm EDFs (6S voltages) at a cost of about $45 each. They haven't flown yet, but I hope they will soon. They are in my first scratch-built EDF jet, an SR-71 Blackbird. But the weight may be too high, 9lbs empty. We'll soon see. EDIT: Sept 2021 It did fly but more work is needed. It's definitely not a VSTOL, although my landing would seem to indicate that. ruclips.net/video/PThsS5iXwnI/видео.html
Small and many is beautiful and powerful!
Thank you
Many thanks for your explanation...Wish to have more from yourself. Thanks again. Yehia Talaat
You are most welcome
hey, thanks for your analysis; I could be wrong about this; but when the "fan surface" is in the vertical orientation or nearly so and is moving forward ; I believe that the overall shape of the airfoil that is created by this configuration is acting essentially as "full span" flaps.
Thereby greatly increasing lift and lowering stall speed.
damn my son must study engineering!
A couple technical comments to this nice video. Impressive the L/D ratio of 21 for such a small wing aspect ratio! With this in mind the vertical take off and landing, even if high power (and energy consumption) have a short duration (1 minute each?) as the plane will transition soon to fixed wing flying in which it will stay most of the time (60 minutes) to achieve the 300 km range. It makes sense to me!
Great analysis of this jet!
Interesting video, thanks.
Great work, one question. What would be the consequences of turning off the EDF during flight, will the air resistance across the free rotating blades cause a stall?
I think the consequences would be dire. Like having full wing spoilers. You'd have to dive steeply to maintain enough airspeed to keep it behaving like a plane.
Flight safety in takeoff and landing is always a concern. A full power loss depending on speed and altitude could be a problem. Redundancy may be needed. A simple parachute system could be implemented. The video presentation shows detail system knowledge and excellent integration. In the design space like to see where battery density plays into the design and what was used for range estimates / speed estimates. Otherwise excellent engineering and design choices.
@@caddymj Speed and altitude with total power loss are inconsequential (unless both are 0) being as that there are no control surfaces. No mater what the airspeed and altitude the pilot is now a passenger.
Excellent tutorial.
Amazing channel!
Thank you!
WOW, nice explanations.
Why not go more into details about the battery requirements and the existing battery tech and the development of new cells
Great summary with some valuable insights... well explained. We are following their progress too.ITPS Canada
Very nice graphics and explanation on their process..I hope they achieve successful flight.
Thanks so much for a great explanation video!
You earned a sub!!
Good work guys
Simply great!
Great video, I understood what was been explained, which makes one of us very clever and its not me 🙂
Very. Well explained
Thanks for liking
Very nice concept, thanks for showing it. Très belle présentation, merci.
Good explanation. Thankyou
Since VTO consumes 10X more energy, the solution is painfully obvious, and it's surprising no one has fixed this yet: Simply have a quick and automatic release power tether that pulls off once the craft is airborne. Maybe give it a 10 to 20 yard length so once the plane gets underway, the forward momentum alone will disconnect the ground power. Then have a cable boy/girl run out and spool it back into the landing zone. Basically, take offs will consume ground power, keeping batteries topped off at full until aerodynamic lift is achieved, or is more inexpensively achieved. The cable length could be adjusted depending on weight considerations, but remember, the power usage would be irrelevant until the cable disconnects at which point the cable weight would be irrelevant.
Just have to engineer a way to control the cable so it doesn't get sucked up and FOD out an engine...otherwise, you're right that is a elegant solution!
@@detour1055 Why would the cable get sucked up? By definition it would be on the exhaust side and would naturally be blown away from the aircraft. As the aircraft rises, cable would be blown downward naturally. Just ensure it's spooled so there's not a lot of loose cable laying around which then could possibly be thrown around with the ground turbulence. But even then the energy that could be imparted to the cable is not likely to be able to throw it above the aircraft into the intakes, esp. since the weight of the cable is always pulling it downward.
@@detour1055 (Also, assisted takeoff and landings are nothing new, the military has been using it on aircraft carriers since the first carriers existed, - although in the old days take-off assists were mechanical, like catapults. Tailhooks and cables I think are still in use for landing assists. This would just be a different kind of take-off assist)
Wonderfully clear video , thanks. Please how does the plane glide when power off, eg an electrical failure?
So good even an electrical engineer can understand it. Although, I flew hang gliders for 12 years so I might have some knowledge beyond my formal education.
Well thought out and spoken explanation. It almost matches the brilliant engineering. Jk
Excellent and very informing. Looks like you have a lot of potential. Perhaps in the future you might also give performance numbers and weights in both Metric and inch/feet/pounds, since in order to really appreciate the numbers, I had to bring up a conversion table and stop the video several times to convert the numbers into terms my 75 year old brain is familiar with. Thank you!
I like 🚁's‼️ 😬😉
(probably a very interesting information for the whole RUclips - Community!) ;]
But seriously, a awesome high-tech invention 👍🏼
Very good explanation, but you didn't cover the main reason these types of aircraft will not be commercially viable... i.e. instability during an engine out event... e.g. if one ducted fan fails during take-off or landing, it will cause instability and roll.
To counter an engine out, the opposing fans must either decrease their thrust, or fans on the same side as fan out, increase their thrust.
If you decrease the oppposite thrust then you decrease overall lift by 19kgf x 2 = 38kgf, and therefore be unable to maintain lift.
If you wish to increase the thrust on the same side as engine out, the electric motors must be able to increase their output by over 38% which they will not be able to do.
Therefore these type of aircraft will not be commercially viable... lots of prototypes... but no successful commercial production...
I am maths challenged but all that made perfect sense to me. What a fascinating vehicle. Like something out of the sci fi of my youth. Gerry Anderson would have kittens!
Thank you a lot. Good job!
You are welcome!
Brilliant and articulate coverage of complex engineering concepts
Really interesting video. I like your style of informing people about this topics.
Academic !!!
I wish you had elaborated on the transition mode and issues arising in such phase. The remark as to the fact that this aircraft may be considered as one having a very low stall speed rather than an eVTOL alludes to one aspect which may be related.
Also, you mentioned EDF diameter vs Power Consumption and vs specific thrust. It would be interesting to hear your thoughts on how Lilium may have determined the sweet spot.
Also, they had in the earlier design a sort of rotating cylinder housing a couple of EDFs in lieu of the current Canard, it would be interesting to hear your thoughts on this change and the tradeoff associated.
Questoin: how much mass do the batteries have?
Amazing video! Very well explained! THKS A LOT
Great video
Thanks!
Excellent video!
Ok, lets crunch some numbers! First - nice analysis of required t/o power! But the main challenge in these numbers is the numbers itself: Energy density! Aircraft gross weight 440Kg with a 320kwh pack? Even if that was just for the battery pack that would mean an energy density of 720wh/kg on pack level. That's easily double the max energy density that current lithium ion accus can provide even on cell level. That being said, the given weight figure is for the whole aircraft! The video mentions that one single of-the-shelf 195mm EDF has weight of 3,4Kg while the a/c actually uses 36 larger 250mm EDFs. So these 36 EDFs alone make up for at least 120Kg of the aircraft weight. To get an even number, lets estimate another 80Kg for the airframe structure, seats, electronics, wheel base, everything else: So the a/c weight without battery would be around 200kg. Only 240kg would be left for the battery pack. So to achieve 440Kg gross weight with an 320kwh battery, the required energy density would be around 1.3kwh/kg on the pack level. That's currently impossible and will remain so for quite some time. Only a rough estimation, but with the numbers given in this video, it's somewhere in this ballpark . Maybe these goals are set far out and they try to start with a smaller battery? Achieving 440Kg gross weight even with a 100kwh battery would still be extremely challenging today.
Hi, great video. May I know where did you get a lift to drag ratio of 21?
It was from a conference paper. RAes light aircraft design conference. 18 Nov 2019. Author is Tim Watkins
nice video
Very enjoyable instructive video. I have now pressed the like button and subscribed to your channel and look forward to watching more of your videos 🙂
Very well explained.