EVTOL... ultralight... I would like to discuss this with interested members

[justsomeguy]

You do understand about Reynolds numbers and the like? Power and lift do not scale linearly with size.

Yes, I am a mechanical engineer with a extensive background in aerodynamics. I have chosen a tried and true high lift (ultralight) airfoil with the stall characteristics where I need them and I am OK with the higher drag it has as I am not going for speed. My calculations and double checking with NASA calculations, for the final projected weight the stall speed in airplane mode falls within 18.2 and 20.4 MPH.
The aerodynamics, construction and flight characteristic are not where I need the help, it is the electronics, flight controls, batteries, etc. I have researched all of this and have found various sources.
I am in need of an experienced person to help me wade thru all the info, etc. and choose wisely...

Thank you for the response. I hope you can help me.

[spaceman]

Hi justsomeguy. The project seems to be very interesting, so can you share some photos?

[dougbush]

You might try the Lindbergh Foundation or VerdeGo Aero.

[BJC]

The aerodynamics, construction and flight characteristic are not where I need the help, it is the electronics, flight controls, batteries, etc.

The battery is the thing that everyone designing an electric aircraft needs help with. Currently available batteries just don’t have the energy density that most designs need. VTOL applications, even more so. Just consider the time, money and engineering expertise that has gone onto the Opener Black Fly, then look at its payload and range. https://opener.aero/pages/about-us

Good luck with your project.


BJC

[CHICAGORANDY]

It comes down to refined fossil fuel having about 60 times the energy per pound vs the current battery capability. And as fuel is consumed the conventional aircraft gets lighter, battery planes stay the same weight. No doubt viable AND competitive e-planes will be created one day, or powered by some other competitive energy source. But I suspect I'll never live to see that day.... maybe my 40+ yr old kids will?

[rwanttaja]

It comes down to refined fossil fuel having about 60 times the energy per pound vs the current battery capability. And as fuel is consumed the conventional aircraft gets lighter, battery planes stay the same weight.

I keep seeing this claimed as a major disadvantage of electric aircraft, but just don't see it. A typical one hour flight in my Fly Baby means the plane is ~3% lighter at landing than takeoff. Big whoop. Design-wise, it's actually an advantage...one no longer has to store the "fuel" along the center of gravity, nor take off with a plane whose CG changes in flight.

I keep imagining a newspaper editorial written in 1904..."The Wrights have invented a ridiculous form of transportation. Not only are the passengers exposed to the elements, they have to lie flat during the entire journey and not move, lest the machine become unbalanced. Though, admittedly, the journeys are short since the machine can only fly a few hundred feet. In comparison, a gentleman traveler may board a train in New York and arrive refreshed in Chicago a day later, enjoying a comfortable berth in a Pullman, dining luxuriously, smoking the odd cigar, a Wright aeroplanist and his ground caravan carrying gasoline, bamboo, linen, engines, and mechanics would be barely approaching the New York State borders."

Give 'em time, folks. There's a LOT of research going on to improve battery energy density, and it'll trickle down to aviation.

Ron Wanttaja

[lnuss]

An excellent observation, Ron. And look at the progress already made, both in aircraft and cars, and in the battery improvements (performance, safety, weight, space taken) in the last 10 years, 20 years, and more.

[steve]

Didn't Mercedes just test drive their new EV over 600 miles on a charge? I remember a coworker boasting he burned 0 gas driving his Nissan Leaf to work and home, a staggering distance of 36 miles. He could make it to work and back the next day, too. But he had better not forget to charge the car else he'd be walking to the bus stop on day 3. And that was maybe only 7 years ago.

[FlyingRon]

Didn't Mercedes just test drive their new EV over 600 miles on a charge? I remember a coworker boasting he burned 0 gas driving his Nissan Leaf to work and home, a staggering distance of 36 miles. He could make it to work and back the next day, too. But he had better not forget to charge the car else he'd be walking to the bus stop on day 3. And that was maybe only 7 years ago.

I used to drive a Volt. It had just barely enough range to make it from my house to my hangar at CJR. I knew I was driving efficiently if I got there on the battery charge. Drive a bit too fast, and I wouldn't make it. I'd pull the plane out, put the car in and let it charge while I was gone. Then I'd have enough to see if I could get home.

[CHICAGORANDY]

I keep seeing this claimed as a major disadvantage of electric aircraft, but just don't see it. A typical one hour flight in my Fly Baby means the plane is ~3% lighter at landing than takeoff. Big whoop. Design-wise, it's actually an advantage...one no longer has to store the "fuel" along the center of gravity, nor take off with a plane whose CG changes in flight.

I keep imagining a newspaper editorial written in 1904..."The Wrights have invented a ridiculous form of transportation. Not only are the passengers exposed to the elements, they have to lie flat during the entire journey and not move, lest the machine become unbalanced. Though, admittedly, the journeys are short since the machine can only fly a few hundred feet. In comparison, a gentleman traveler may board a train in New York and arrive refreshed in Chicago a day later, enjoying a comfortable berth in a Pullman, dining luxuriously, smoking the odd cigar, a Wright aeroplanist and his ground caravan carrying gasoline, bamboo, linen, engines, and mechanics would be barely approaching the New York State borders."

Give 'em time, folks. There's a LOT of research going on to improve battery energy density, and it'll trickle down to aviation.

Ron Wanttaja

Ron, I do NOT disagree with or question your statements regarding weight shift. I ain't no pilot ner nuthin' - lol The available 'energy per pound' of "fuel" however remains the current chief stumbling block for e-powered flight vs fossil fuel. I was just watching a nifty YouTube about that 9 passenger all electric aircraft in the works. The reviewer made it clear that 9 passengers was the limit because of the nasty battery weight thing. The added weight of more available power to carry more than 9 would actually just be used to carry the added battery weight. here is the vid I referenced -

https://www.youtube.com/watch?v=b01nE83bmx8

Again, I have no doubt that 'someday' that wide gap between liquid fuel and the battery WILL move much closer to each other and make many of the present e-dreams a reality. But I'm 73 and doubt it will happen in my lifetime.