Industrial 3D Printing Accelerates Electric Aircraft Time-to-Market

[drawoh]

Industrial 3D Printing Accelerates Electric Aircraft Time-to-Market

Not an aircraft designer. Just a curious techie.

There is a link to the manufacturer's website. The aircraft in the picture does not look like a good design. The windows and doors are close enough together that the remaining structure has to be weak. This thing is pressurized, with a maximum altitude of 35,000ft. Two of the engines are out at the wingtips. If one wingtip engine goes, the remaining engines will be wildly asymmetric, leading to control issues. If you are designing and building three engines, why do three of them? Why not make them bigger and just have two of them, located much closer to the fuselage, of course. Where do the batteries go?

The article makes it sound like they are in prototype fabrication stage. The pictures look like an artist's impression, not the work of a design engineer who has tried to solve technical problems.

Does this look real to anyone here?

--
JHG

 

[rb1957]

where to start !

three engines gives you more tolerance to the engine failure case. If there is a tail engine, it'll make for a very tippy plane ... the MLG look to be a long way forward ?

wing tip engines ... well, someone heard that adding weight to the tips is "good", and someone wanted an aft door.

I wonder if the tip engines are only generators (as propeller diameter looks small), and the driving engine is in the tail ?
If so, I'd add a vertical fin, to protect the prop (during rotation)

windows ... maybe they using "stressed glass" (transparent Alumimium, like StarTrek?), like the windscreen ?

design is a very complicated, interactive exercise ... design decisions are good points and bad. minimising the bad is more important than maximising the good.



another day in paradise, or is paradise one day closer ?

 

[3DDave]

When I don't see a 1/4 scale RC model being flown for a concept like this I think it's a Moller emulation company.

The website suggests the plane isn't going to be pressurized and will have a 10000 foot limit. They claim to have a small UAV with a 35k limit.

Check their videos

https://www.youtube.com/channel/UC8rr4q717HUrQHiIES6DcaQ

I like the part of the Stratasys ad where he points out how much they learned from the electric motor mockup without mentioning what they learned. I guess it's a surprise the rotor turns. Note the mock-up has cooling fins the delivered motor doesn't have.

 

[GregLocock]

They're using a mix of Lithium and Aluminum Air batteries to get a total energy density of 400 Wh/kg, Lithiums are around 250. Al/Air has a high energy density, but is not rechargeable. I would expect the batteries in a passenger aircraft to have a lower energy density than automotive ones, for the same chemistry.


Here's what wiki says about Al/Air

The Al/air battery system can generate enough energy and power for driving ranges and acceleration similar to gasoline powered cars...the cost of aluminium as an anode can be as low as US$ 1.1/kg as long as the reaction product is recycled. The total fuel efficiency during the cycle process in Al/air electric vehicles (EVs) can be 15% (present stage) or 20% (projected), comparable to that of internal combustion engine vehicles (ICEs) (13%). The design battery energy density is 1300 Wh/kg (present) or 2000 Wh/kg (projected). The cost of battery system chosen to evaluate is US$ 30/kW (present) or US$ 29/kW (projected). Al/air EVs life-cycle analysis was conducted and compared to lead/acid and nickel metal hydride (NiMH) EVs. Only the Al/air EVs can be projected to have a travel range comparable to ICEs. From this analysis, Al/air EVs are the most promising candidates compared to ICEs in terms of travel range, purchase price, fuel cost, and life-cycle cost.

Technical problems remain to be solved to make Al–air batteries suitable for electric vehicles. Anodes made of pure aluminium are corroded by the electrolyte, so the aluminium is usually alloyed with tin or other elements. The hydrated alumina that is created by the cell reaction forms a gel-like substance at the anode and reduces the electricity output. This is an issue being addressed in the development work on Al–air cells. For example, additives that form the alumina as a powder rather than a gel have been developed.

Cheers

Greg Locock


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