Interesting video as always. The efficiency multiplier for distributed propulsion is amazing! I can imagine small regional airports coming back to life with an increase in electric STOL aircraft services.

I love that you find so much new and interesting information. I just love this channel !

Best panorama of these i've red or watch so far. Very instructive and conclusive.

Yes, finally. Real efficiency improvements over getting a brick to fly.

Interesting presentation of the benefits of ESTOL over EVTOL for many applications.

This channel just keeps getting better and better. Keep up the good work!

Short-range use is exciting! You can get 4 miles/kwh with USTOL (Ultra-short Take Off and Landing) if you can live with a 100 mile range, which is well within commute/recreational use! Even those high-maintenance, high fuel use helicopters never travel more than about 50 miles from base. I could see every TV station (if they still exist) ordering one to replace their "traffic copters", and Med-Evac very quickly shifting to multi-motor EVTOL (special case where VTOL is required).

I love this channel so much, keep going! I believe nothing can accelerate the transition to sustainable aviation as much as public interest and support!

there's a lot of focus in this space on making Uber's business model work but I can see this type of craft really revolutionizing general aviation and hopefully improving the safety record.

Love the depth and thought put into your content, ^oo^

Some info presented here are not quite true. Distributed propulsion usually performs worse than a single rotor if you consider propulsion alone. This is due to degradation of the flow characteristics on the blade due to smaller Reynolds numbers. I have discussed this with Dr. Nick Borer from the NASA X-57 DEP CTOL aircraft team, he specifically mentioned the smaller propellers used for distributed propulsion were performing badly, about 50% efficient, and that's why at higher speed they are stopped and folded. What the distributed propulsion actually does - it increases artificially the wing lift coefficient, the wing can be much thinner, having a lot less surface area, without a reduction in stall speed, but having much better high speed performance. Having a smaller chord wing, same wingspan, increases the maximum L/D and moves this maximum at a higher speed on the L/D characteristics. The smaller wing actually is the reason the range increases, not the multitude of propellers. The distributed propulsion is to allow the wing to perform at slow speed and have a relatively slow stall speed, similar to the original larger wing.

Amazing. We should really go for it. Less pollution, less roads, more flexibility, less traffic jam, more live quality, more terrain for agriculture, shorter commute between X and Y, lots of advantages. Smaller plains, less components, saver, cheaper, less CO2 footprint, more aesthetic, less dependence from large companies with goal to exploit you. Go for it!

Exciting to see how we are gaining new insights all the time. This really helps me feel more positive about the future that awaits my children. As always, I particularly love your delivery - concepts are articulated with incredible clarity and always with context. You have an exceedingly rare ability to communicate at this level and I often refer to your videos when I am preparing presentations myself (I have been in management consulting around the globe for over 20 years). Regards and thanks from Sydney - Dave

Something I feel worth discussing: One of the big issues for current electric aircraft is the need for reserve endurance - if a problem develops at your destination airfield, you need to be able to fly to another one. These reserves are relaxed for helicopters as in an emergency, they are more likely to be able to land safely without an airfield. This means that aside from other advantages, in comparison with a conventional aircraft a VTOL vehicle should be able to make better use of its ultimate range. Thank you for a very interesting video. I learned a lot from it.

Very good video as always! I wanted to share some constructive feedback (hopefully!) though that your focus was more towards the takeoff performance than the range aspect in my opinion. (Ex: @6:15) Takeoff is such a small phase of flight that its power requirements are sometimes insignificant to the range. It's clear that there are benefits to distributed propulsion. Since lift is proportional to the speed square, the relative velocity increase provided by the small propeller can give large gains in lift. Additionally, the Reynolds number is increased, and typically the CL is higher with higher Re. But the research you link also shows some compromises that have to be made for each application. Despite having a higher thrust to weight ratio with the smaller motors, the aircraft was 11% heavier than the base aircraft. I cannot see the study, but did the aircraft use less power to cruise even when it weighed 11% more? Because that's what really would affect the range.

Yo - this dude presents his stuff really well👌✍

Excellent!

Nice job!

Fascinating videos, thanks

amazing

Nice!

Interesting

thanks for showing DEP and boundary layer ingestion. i think that with distributed propulsion is more appropriate to use closed wings as joined wings or box wings because it gives more structural stability and reduces flutter, a trade-off of distributed propulsion.

Another amazing video, thank you! Is there any research on the electrification of high bypass jet turbines?

Fascinating drag reduction of the many movable,you have made a comprehensive history of aviation,you are a scholler of flight,good visuals 2 communicating the possibilities of a pure electric development of flight with little propeller flight ,straight up into the cruise multiple people/cargo load bearing capacity at highest speed ( :maybe capacitors could give batteries a boost on take off,or we could make big half mega bridge's into the ocean ,and shoot them of from ground batteries into full cruising speed,you could have bicycle s and car's drive into wings and battery,and are shot off the half bridges without there tyres/axel and chassis,batteries would be interchangeable with rentable wings

Just make a wing within a wing for take off, then it slides into the shorter cord for faster flying...

Some very interesting information. Now the question is will an electric version of a turbofan jet engine be even more efficient? The electric motor would replace the axial flow jet engine. Keep up the good work. I love to see people thinking outside the box.

The next level is to replace the electric propellers with electric compressors, each directly connected to an oblong shaped bladeless fan built into the wing's leading edge so as to deliver the maximum laminar flow distributed across an optimized wing surface. So you are multiplying the lift and and mechanical airflow both. This should result in doubling the range again over the propeller design, allowing the electric system to easily beat the conventional one in subsonic flight. One could also incorporate a hybrid power source as well, making electricity onboard in an optimized RPM range for efficiency. The resulting efficiency in fuel consumption would approach an order of magnitude, the electrical approach allowing the optimal mechanical power distribution for a given form.

@ 5:27 is the take off formula, I'm doing this for me but it's information worth noting on

I can’t wait for someone to build a bush plane redesigned to fit multiple motors for super short take off and landing. Those bush plane pilots would know how to make the best out of it!

Great informative video on the advantages of distributive propulsion and eSTOL being more energy efficient than eVTOL. Will you investigate the PLIMP hybrid airship design and give the pros and cons of the design?

7:46 a tilt-wing version of this aircraft could be a very efficient EVTOL. Interested in knowing more abut this particular aircraft.

intelligent propulsion company, owned by rogers msuya, has invented something new that can generate electricity onboard... eliminating all hurdles facing the Electric Mobility today!

Exactly. :)

I did watch your video on fuel cell flight, and still don't perceive you gave a fully realized evaluation on that, but this was informative (for me) about take offs (?)... Did you say there's a larger drag coefficient at certain heights, weights & speeds?Also still also a matter of public access, when it comes to vtol flights without runways, & nothing is wrong with romance... It's romance which is correct.

would the lift be higher when the props are located above the wing rather than below as with the NASA design?

The biggest problem with eSTOL is safety. eVTOL machines are fundamentally safer, and there is a lot of designs that are optimally cruise efficient.

Can distributed propulsion setup with small open propellers also achieve the high top speeds of a large EDF in forward flight? Hey how do I get in touch with you?

VTOL would be great mainly for short hauls in the city and no transformer shape change necessary with the short distances. I agree STOL is way better especially without any transformer shape change which makes it easier to make, lighter and simpler. And you maybe can design STOL to near VTOL performance. e.g. A semi Black Fly idea with wheels and a slow landing speed that can easily stop short.

Thank you for your excellent work 👍👏👏👏... you have basically insinuated that we are about to see micro airports in the middle of bedroom communities around the country... quite and clean aircraft will change air travel completely

Please provide a reference for the Takeoff Length equation 13.WingLoading/(TtoWt*Cl)

What about the drag all those propellers create?

Very good coverage of this. VTOLs are likely destined to serve as urban robo-taxies rather than go to traveling vehicles, imho. Could you cover this aspect please?

How does blown air increase lifting coefficient? Thank you

Do you think Joby and Vertical will be able to take off and land like a conventional estall aircraft where it’s appropriate to do so and save some power for longer missions

What about speed? How is it affected with the number of propellers?

This guy: Talks in depth about the science behind and efficiency of battery powered aircraft Also this guy: Refuses to replace the dying battery in his smoke detector

Electra Aero 😍

Two things come to mind 1/ that trailing edge or pusher propellers would endear a straighter, more predictable flow over the wing, especially concerning the leading edge; further optimising Clmax 2/ and Im unsure the advantage of short take off, as the present experience deals with 'average' take off durations quite well, ... and hull insurance on STOL aircraft has proven in the main to be commercially prohibitive ok make that 3 things ....

Luv, the channel . Btw, that wasn't a Mig-21 .

This is a remarkable video. There is clearly a very good business case for the light private pilot aircraft segment. Why is this not being pursued? Also, can you state what each of the prototype EV aircraft you were showing in this video are? Probably with a link. What was that dual wing, multi-prop one with the tricycle landing gear? And the DHL one? Would like to know who's behind these designs. I get the feeling that many developers are approaching the design aspect wrong, based on what you're saying. Someone should start by just designing the optimal airframe and propellor setup, and work back to a working aircraft from there. And all propellers should have the capacity to stop and fold along the motor in order to allow more efficient travel at cruise speeds and altitude on just one or two motors.

Check out the XTI Aircraft Trifan design....gas turbine driving a generator that powers motors driving ducted fans which rotate for either vertical or horizontal thrust. XTI plans to replace the gas turbine with batteries when battery energy density improves. Full disclosure: I own shares in XTI aircraft.

Seems like it would be worth while to create launch assist drones that attach temporarily to the craft, and they would be designed to provide one minute of thrust before they disconnected and fly back to be recharged for the next launch. Anyone doing that sort of design?

It would be interesting to see if a craft with a large rotor that is driven by small propellers along its length would be worthwhile.

What about size of the aircraft? Is there an advantage/disadvantage scaling up.

So, using 100hp motor with 8' dia. prop, would burn more fuel than four 25hp motors, each with a 4 foot diameter propeller? Would the propeller design and rpm's make a difference?

Solar powered electric airships (rigid Blimps) could take over a huge portion of freight flights point to point with almost no infrastructure. I’m amazed there is so little interest. Point to point at 120 mph with no wear and tear or clogging of roads would be extremely helpful. Quiet and no pollution also good. Modern technology would mitigate hydrogens flammability as it has lithium.

Yeah, but in an STOL you are still taking off and landing on a runway, which is existing infra usually built far outside of the city. And even if you start building custom runways of let's say only 50m you still need empty space for approach, and for city travel that's still a lot of prime real estate space dedicated for landing infrastructure. The reason people are excited about eVTOLs is specifically that it enables point to point because the landing infrastructure is so much less involved. Nothing to do with flying cars.

Dear Electric Aviation, we are big fans and followers of your work, we are currently working on a project where we feel that your expertise could be of help, do you ever do any consultation work? please contact us as we would very much like to speak with you.

I see a lot of companies pursuing VTOL and think of the wasted energy. VTOL is unnecessary in most instances and only serves to increase the cost of flying. I am excited for full electric aircraft, however I am impatient. Can you do a video analysis of Pipistrel's Panthera Hybrid system?

Distributed propulsion simulate what a bird wings would do if it was flapping its wings to get lift. The airflow is evenly distributed over the whole wing and not just a section of the wing. They should design bigger aircraft with this in mind.

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This makes total sense, and clarifies the thought I had for a very long time! Always felt VTOLs are overrated. STOL removes a lot of complexity required for the VTOL functionality, like tilt rotors and bigger propellors etc. Most people anyway won't be able to afford to fly in electric helicopters even if someone launches it. Making it simple makes it cheaper. Very good content and analysis, keep up the good content!

If you use Edison generators and dynamos rather than battery powered electric can allow much more powerful electric motor.

Please clarify what you mean when you say "5 times more propulsive efficiency" with distributed propulsion @6:58. Propulsive efficiency cannot be greater than one. Do you mean a 5 percent improvement? Thank you.

I wonder what would happen if you put little propellers on a big propeller.

What about having a ICE running multiple propellers, say 4?

I'm confused.. if distributed propulsion is great for range, why does the NASA X-57 Maxwell only use it for take off (and landing)?

Can I help you with the Edison generator and dynamos to power your plane without battery powered . Fully unlimited electric power planes.

What's the model name during the 5:15 to 5:28?

God: the only way multi props will work & b efficient is in the FAT thick wing trailing prop design & the air-foil prt shape of the wing is the channels between the props.

Very interesting. The lack of energy density in batteries is certainly forcing people to squeeze the sponge hard for every last drop of advantage. I wonder what would happen if tomorrow we had a game changer where we saw density at a 1000 times what it is now. It would probably put efficiency chasing on a back burner for quite some time so maybe the lack of density we have now drives a science benefit in other areas we would not have otherwise had.

Car's flying cattermerangs,gigantic shipping crude oil splerter's with paragliding sails/giant kites pulling them along in part with shipping lanes battery packs ,improving the sea and the cities,and the air

My hope is a combination of small STOL aircraft with AI control system would liberate humans to live in smaller towns. Current flight tech makes travel from smaller towns not economic, with most only achievable with large Govt subsidies. If the cost of the flights is halved, likley even more with the low cost of electricity and much reduced maintenance of elctric motors compared to ICE planes, chosing where you live can be much more about lifestyle.

Does electric propulsion have anything to offer sea planes ?

I really do wonder if the best combination would be a ground effect aircraft with hydrogen fuel cell electric propulsion for at least 80% of propulsion needs of 50+ person passenger aircraft... 🤔🤔🤔

Adwantages? There’s no V in that language?

The F-104 used blown flaps? Who knew!! 🤗

Hello, At 3:22 you say that smaller motors have high trust to weight ratio, but when i look at another video you put online: kzfaq.info/get/bejne/hZamhMWEy9vZlnk.html And you go to the stats at 04:24 I see that the trust to weight ratio is lower. Can you or maybe someone else explain this to me? Best regards, Jan

They need to make them quieter.

Time someone’s makes a super high bypass single shaft electric monster to rival a ge90’s record 134,000 ft lbs of trust

if batteries are designed to be easily swapped out then electric vtol air taxies could become a thing - every air pad could have charged batteries waiting to be swapped in

@Electric Aviation If distributed propulsion is more efficient why Airbus and Boeing are increasingly making commercial airplanes engines bigger and bigger ? In the past they had 2 or even 3 engines per wing and now they have just 1 big engine per wing, so if distributed propulsion is more efficient, Why they didn't made the jet's core smaller (in order to increase the bypass ratio) instead of making the fans bigger and leaving just 2 big engines ? And now Why are they making them even bigger instead of putting more engines ?

Do not over amp the motor use the Edison generator for electric power source. An old generator can be converted to Edison power by chiseling off the Tesla magnets and leaving the Edison magnets on the generator armature. A pre 1974 car generator can be used count the armature magnets and divide by six and chisel off one sixth and leave one sixth on and then off and on until you have chiseled off three sixths and left three sixths on alternating on and off. The generators are motors and will spin as you assemble the generator. The generators self spin unlimited generation of electricity. You have replace the commutator brushes. Add inverters and transformers to deliver power plant power or house current. But 12 v power continuous peak power or 110v AC is immediately available for airplanes power for an unlimited time . Redundancy is safer.

Jetoptera: propellers are so passe.

Don't forget to replace your battery in your smoke detector.

I listened to this video hoping for some kind of explanation for the claim but heard nothing. Therefor, I believe that in the absence of rational scientific cause, the claim is bogus. The video did mention what I consider critically important, which is the calculated thrust to weight ratio of the engine and aircraft. But, I heard nothing about why distributed power should be more efficient or be reason for a superior thrust to weight ratio. I will say that AFAIK, fewer and larger props and engines do run into certain limitations... The propeller tips must not travel faster than the speed of sound. The propeller must be optimized for a particular speed. An optimized propeller will account for the different radial velocities closer to the hub and along the propeller to the tip. Of course, an optimized propeller will have an airfoil shape. There can be additional features that can help propeller efficiency like ducting. Maybe the idea is that with smaller propellers, the extreme difference of the propeller's efficiency from hub to tip is possibly less, but that might only mean a less optimized propeller shape might be required. It might mean that with smaller propellers, the propellers can spin faster, but that's hardly related to propeller efficiency which also depends on airfoil, angle of attack, materials and more. So, based only on what is in the video, I don't think that its claim is accurate. Need proof, or at least a sensible argument.

The more motors and propellors you add the more weight and drag you add. So adding a bunch of motors defeats all objectives. Thus guy does not understand why early aircraft had many engines. It does nothing positive once you meet redundancy requirements.

Until they figure out how to mass produce graphene for batteries electric vehicles are just too impractical.

Until they can build reliable safe and stable batteries with 12,000 watt-hours per kilogram, electric planes are just toys for rich people.

I've never understood this concept.. why multiply the drag penalty of one small propeller 10x times when it is well known bigger propellers are more efficient... efficiency is a much bigger deal with limited on board energy. This does NOT have better propulsive efficiency. Whoever told you that is either full of shit or has no idea what they're talking about. If this wasn't the case, then turbofan engines wouldn't exist and the fan part of the turbofans wouldn't keep on getting bigger and bigger.

Electric motors are not called "engines"!!!!!!!!!!