what documents Capo?

@@lorenzocapasso8881 see page 17 www.google.com/url?sa=t&source=web&rct=j&url=www.bbaa.de/fileadmin/user_upload/02-preis/02-02-preistraeger/newsletter-2019/02-2019-09/02_Siemens_Anton.pdf&ved=2ahUKEwjt-4vEwcHxAhUR8HMBHYXvDdMQFnoECC0QAg&usg=AOvVaw2RTn8H-EZOjaa3DPJbBhoA where it speaks of redundant windings. I recall seeing similar wording used by some of the eVTOL manufacturers.

@@RichardRParsons that's an interesting read. I wish there was more info about the redundant windings besides one mention. I'll look elsewhere for info. The practice has been in place for decades in multi-speed 3 phase motors. Two independent sets of windings with one contactor for each. One set is low speed and the other is high speed. I could see the electric aircraft motors running only one set of windings at any given time except for vertical flight so that they and the associated controllers aren't all wearing out together.

You are right. Beta has its merits

I have covered Talyn Air and AMSL in separate videos

My pleasure!

I'll try!

Hope so!

Agreed, Transwing has the most compact ground footprint and the most efficient cruise.

Thanks for watching!

Noted

Glad you enjoyed it

Thank you. I am a Mechanical Engineer, with PhD in Renewable Energy. Aviation is just a hobby of mine.

Your persona and rock solid expertice is why this channel will explode! But I think the channel would it grow even faster if you would set up a studio to be able to appear yourself in parts of the commentary of the videos.You have fans and they want to feel a personal connection.

​ @MattiasAllring Thanks. Very flattering. I will have myself in the field videos that hopefully I will do when I visit some aviation companies. At present I dont think it adds value showing myself in explainer videos.

For me, having low noise eVTOLs are ideal for commuting in rural areas. Solid State batteries will be the next step. We have achieved 350 to 500 Wh /kg in the lab. Current batteries being used in EVOTLs are 275-250 Wh/kg. This will increase the range or payload significantly.

@@ElectricAviation Sure, but a fixed wing aircraft with the same battery will have even more range. As long as there is no special infrastructure with landing permits and recharging stations for eVTOLs, they would have to land at normal airfields anyways. Burocracy is slow. I love electric aviation, but I think take-off from a conventional runway is still the way to go. Why would we need vertical take-off in rural areas where space isn't a problem? The only argument is the potential for automated flight, without a pilot. In the city I would understand the VTOL argument, but then there's still the noise: keep in mind that a lot of the noise doesn't come from the engine, but from the propeller. Less noisy doesn't mean it's not still annoying. Whether noise is disturbing is also a matter of frequency. E.g. the noise of a Rotax 914 (internal combustion) is much more annoying than an IO550 in my opinion, even though the IO550 is the larger engine. Why? RPM (no gearbox considered(Rotax)). Electrically driven propellers also have a similar problem with high frequencies due to also typically high RPM (in this case prop rpm). --> I don't think the noise problem is really solved. It would still be too annoying in the city. In summary: electric flight=great, electric VTOL flight=not so much, until proven otherwise

@@___Chris___ I agree the fixed wing electric will see more success in the near future. France has banned all intercity flights that are within 2 .5 hours away on the rail. This is where fixed wing electric aircrafts can come in. As for eVOTL, they are driven by romanticism. It is the age old dream of having a flying car. With eVOTL, people can see that its finally becoming true. I believe that Jaunt Aviation's Rosa has a lot of potential for city centre to airport hops. And it offers safety too

Thanks!

Thanks a ton

Doubt it

The ducted fans need much higher power during hovering which requests a much higher power density of the battery. Generally, power density and energy density are a trade-off in battery design. Meaning they won't be able to using the high energy battery compared to other design

​@@xuyan2650 Well, they don't have to. On cruise, the Lilium jet uses 10% of the hover energy. Hover represents only 5% of any trip time. Lilium optimized for the Cruise stage while the rest did it for hover. Ducted fans is the only design that can scale without increasing size (bigger than helipads) or noise. I just uploaded my video on Lilium Jet, I talk about this. The Paper from Lilium on the 7 seater jet goes more in depth. It is interesting to see how all this is gonna play out!

@@eVTOLinnovation The energy (kWh) makes sense. However, the higher hover power requirement requests higher power density from the battery and lower battery impedance in order to make sure the motor can draw the energy out of the battery. For the hover case, you can't draw the power out even you still have energy inside your battery due to the low power density. I will look at your video first and see if I missed anything. FYI the link of the 7 seater paper under your video doesn't work for some reason. it shows 404

​@@xuyan2650 Fixed the link. Thanks for letting me know. Do you think Lilium is speculating with a battery breakthrough in the next years to be able to fly? I think if they really had battery problems they would have stayed with the 5 seater or even a 3 seater. It is hard to know, I am not a battery expert and we don't have all the insider information. Thanks for your insights 👍

So your having a HARD TIME computing the TRASH multiple millions of DOLLARS went into?... I AGREE 👍 💯 😁

@@tuzisawsome2199 no I wasn’t being negative, quite the contrie, unless they are judged to be miss spending public money, I don’t think they are, then I don’t see the problem. Evetol investor right here.

@@TeslaBulldotcom no you fool 🤣 I gave you a back handed compliment lol... but seriously, please either don't call these evtols or just call them what they ARE, TRASH! IF You're seriously investing now. I suggest you stop and wait till the fall. Maybe you'll be shocked then, to see something REAL.

Glad you liked it

Its an idea with a lot of potential. Reminds me of Zipline drones and how they are delivering blood in areas where there aren't event proper tracks leave alone roads. www.bbc.co.uk/news/av/technology-43886039 They use a ramp-sling launch and a sky hook so almost all the energy in the battery is used for cruise. Something similar can be done at vertiports.

They are

If you like the tiltwing, have you seen the PteroDynamicsTranswing design? kzfaq.info/get/bejne/adt-ldJ0zKqze4U.html

@@codetech5598 Thanks that's interesting. I imagine being compact could open up some opportunities.

@@dejayrezme8617 There are other aircraft with wings that fold for storage or transport, but the fact that the folded mode of this aircraft is the exact mode for takeoff and landing make this design ingenious.

That information in the video was actually very strange. Usually, 2-blade propellers are the most efficient. Anything more implies unwanted interactions between the blades, losing more than we gain, because the blades pass through less "clean" / more turbulent air of the preceding wake. Theoretically, counter-balanced single-blade propellers would be even more efficient (yes, they exist, although rare), but they are otherwise problematic because of vibrations (balanced around COG, but not aerodynamically), therefore practicality starts with 2 blades. The reason why 3-blade propellers are also seen quite often in smaller GA aircraft (or even 4 or 6-blade propellers e.g. in turboprops like the ATR-72) is ground clearance. Very typical e.g. in Mooneys, sitting rather low with their short retractable landing gears. When we want more thrust per "disk" size due to space constraints, more blades are good, but when the goal is more thrust per kW, then 2 blades are best. When that's not enough: more engines with 2-blade props of their own, or just larger props (as long as the combination of prop diameter and rpm doesn't lead to suprasonic blade tip speeds). Now, with these multi-bladed sandwiched propellers - either co-rotating or counter-rotating - it's hard to imagine how this is supposed to be even remotely more efficient. I would expect a lot of chaotic interferences, especially because these blades are likely with a fixed pitch, thus never really optimal for their speed. When the front (or upper) rotor starts to partially stall, the rear (or lower) rotor will be in a lot of trouble. Swirl "recovery" with counter-rotating blades is also relative. Yes, it avoids the actual swirl / slipstream, but still with a lot of drag losses through interactions between the 2 rotors. With co-rotating rotors: probably worst of both worlds (I think you were suggesting something like that, if you understood you correctly). [disclaimer: no aerodynamics expert, just a private pilot]

d1rkab7tlqy5f1.cloudfront.net/Studentenportal/Faculteitspecifiek/LR/Onderwijs/Thesis/Wind%20energy/20190911%20Shubham_kickoff.pdf

Though it is an opinion, it is one that I share. I have a tonne of ideas about this but as far as being the "simplest" that seems to fit my understanding as well. Unfortunatly I can only work on RC scale but some day brother/sister.

True. Only down side is it's noisy like a helicopter.

@@agrxdrowflow958 they do make a fair bit of noise but we can change the rotor tips to make less noise. I work with ducted fans on my projects.

It is the new thing in drone tech. So yes, you are spot-on.

Embraer -X are doing it and CityAirbus have got it. I think Vertical Aerospace mentioned that they found Ducted fans challenging in forward flight so the removed them from their prototype.

Thank you

The blast from them is one of the most corrosive jet of plasma known to mankind

@@ElectricAviation what if the propeller blades are placed in the jet like chamber. do it have any advantage like reducing the turbulence within the space between propellers or it is just an extra wasteful weight?

To conserve battery energy. If you fly very fast, the distance covered will be less, but you will get their quicker for the same amount of energy. Most of these aircraft are designed to fly at 150 mph and cover 60 to 100 miles

I have a video on that

hybrid e-vtols

best evtol is helium balloon dirigible, which does not care about gravity

wings can be supercaps graphene

or lithium battery wings

Having a constant force via constant dynamic pressure (air density * velocity^2) means a high velocity in thin air. Since F * v = P, you can easily calculate power required (*0,8 efficiency) and therefore range

You can have the same power level (like 200 kW) in thin and thick air, but in thin air you travel much faster even if KTAS is the same. Requires less energy per distance.

Jaunt Aviation ROSA

You can have two tilting links for redundancy

Kind of ironic considering helicopters have many single points of failure

@@wpfilms2 Good point. Helicopters are certified to FAR part 27. Big airplanes are certified to part 25. Small airplanes are certified to part 21 or 23 and it's not clear to which evtol's will be subjected and the safety standards are completely different.

I have plans to cover it. Its in my list

@@ElectricAviation Excellent. Your channel has the best and most detailed information on KZfaq.