UKH

OK it isn't designed for passenger flight but this is interesting. 

https://www.bbc.com/news/uk-scotland-48013519

That's a very clever application of a simple idea. It's never going to be fast and helium is going to be problematic but making use of the winds aloft like a balloon and their ability to self-propel to navigate I can imagine a low energy long-haul air freight/transport network being possible.

I suspect as fossil energy becomes costlier we'll see a lot of interesting hybrid transport concepts developed to make use of solar and atmospheric energy.

jk

Sourcing large volumes of helium could be a problem in the future, until we can make more efficiently.  

Just need to get those pesky fusion reactors to work...

Atmospheric abundance isn’t atrocious.  

Extraction is currently very expensive but there’s been no incentive to work on that problem.  

I’m still holding out hope for lighter than air solids, some sort of evacuated aerogel.

I wonder whether and when we'll be able to make viable vacuum 'balloons'.

It'd need clever materials that could expand and contract to vary the volume of vacuum inside to achieve the desired buoyancy, but it seems as if it should be possible with a bit of work.

Edit - sort of crossed with wintertree.

I suppose it is a conflict of being able to create, maintain and contain a vacuum, whilst still being light enough to be lifted by it. 

Carl Fredricksen seems to have made them work

https://en.wikipedia.org/wiki/Up_(2009_film)

Neat but I was wondering how it would perform in strong headwinds.

Here's another view of the future: lillium.com

(you might need to paste the name into your browser, I can't paste a link on my phone).

while I was at BAe in the 80s we had an idle conversation during which I proposed (to no one who had any influence) a hybrid design that was perhaps 20-35% airship and the rest conventional.

The idea was to have a less dense aircraft to lift off the ground and keep in nthe air and also to allow it to be intrinsically more stable due to the arrangement of buoyancy within the structure.   Just a flight of fancy, sadly, like my idea for a hybrid fuel/electric car with electromagnetic braking (storing a bit of charge back) in a 1971 physics lesson that was dashed to the ground by the teacher.

I suppose one gets conditioned to the idea that one's ideas are crap

Is that a convoluted way of saying there's a lot of helium in the atmosphere? 

The Lillium craft is also interesting. Like a bumblebee it looks like it should be crap at flying, but it works. And it's cute!

Your way took twice as many words as mine, so I’m not sure “convoluted” is accurate.  

You can even make a cold air open boat float if your atmosphere is thick enough -  youtube.com/watch?v=N9vvJQniYsc&

There are easier ways of adjusting buoyancy, for example compressing air into high pressure tanks to store mass.  You could recover some of the energy when you let it back out again.  COPV pressure vessels are very light and can store very high pressures - ideal apart from perhaps some explody type issues still being ironed out.

True. I wasn't having a go, just making sure I got your point. I'm not sure if large scale extraction of any kind of gas from the atmosphere is a good idea.

Actually a less convoluted way of saying that "while the helium content in the atmosphere is low, it is not so low as to make atmospheric extraction impossible as a source".

Industrially helium isn't extracted from the air anyway, it's either removed from natural gas when it's liquified or from underground reservoirs, there's a big one under the Rift Valley.

You did.

Happens on a regular basis.  Its where industrial liquid oxygen and liquid nitrogen come from.  Been going on for ages and it all goes back to the atmosphere, as would most helium if we end up having to extract it from the atmosphere.

About 1,600,000 kg of helium boils off from the atmosphere to space each year.  I think that’s more than current consumption rates.  Most consumed helium ends up in the atmosphere.

Perhaps that’ll be an eventual use for the research going on in fusion.  An energy negative transmutation machine to make Helium - more attainable than net positive power generation....

We're seeing a plethora start-ups/designs like this being promoted as just-about-enabling technology reaches the mass market. Hybrid concepts like this with conventional fixed wing capability merged efficiently with vertical take-off and landing performance do look the most appealing for point-point regional personal transport but the energy problem is really hard to ignore, flight is power hungry. I suspect at present the vast majority are doomed to fail (or succeed as development cash hovers depending upon your degree of cynicism) as they crash into physics, immovable regulatory and the associated cost and complexity hurdles which price them out of the mass-market (and exacerbate the physics issue by piling on weight). Aviation regulation is deeply conservative, the mountain isn't going to come to Mohamed here. Aerodynamic efficiency is the key to battery electric aircraft but it's hard to see how the restrictions imposed by the need for ultra-efficiency (wingspan, laminar flows) can be pulled together with those for convenience (cabin space, compact design, unconventional layout for stable VTOL) and if they somehow could be then how cost could be controlled. Actually the Lillium thing looks quite a sensible compromise but one that is waiting for higher energy density batteries and buy in from a wealthy user base to see it realised commercially.

jk

Interesting. I didn't know that.

Lillium seem fairly confident about their technology and have managed to persuade investors to give them $100 million. I think they hope to have flying autonomous taxis (sorry aln) in production in five years.

How green they are depends of course on how the electricity is generated.

The issue with flight is that it is intrinsically more energy intensive than wheel or rail based travel. I assume we will be stuck with jet engines for the foreseeable future. Hopefully, though, the type of fuel will change to something CO2 neutral, such as H2 generated using renewable source electricity.

CB

Assuming oil is used anywhere else on the planet that could instead be grid connected to renewables for its energy, it’s probably greener to use the oil on the aircraft and to use the investment to decarbonise the other oil plant with the renewable energy.  The round round trip efficiency with renewable generated hydrogen sucks - avoiding that inefficiency by displacing oil elsewhere brings better total savings.

If we do have to move to renewable synthesised fuels for aircraft I wouldn’t expect to see hydrogen used outside of air breathing hypersonic stuff as it’s got so many other problems.  Renewable synthesised heavy oil is much simpler to swap in.

When it comes to dumping oil as a fuel I’d look to ships long before aircraft.

I'm sure but might the need to hoover up that 100M explain some of the 'confidence'?

I bet they don't have a product ready in five years. With all that funding they'll probably have a prototype they can fly on a limited experimental certificate, one that falls miles short of the required performance specifications and does not answer most of the regulatory compliance questions they'll face. Then they'll almost certainly need new law to operate the thing around other airspace users and earth-bound interests which will be powerfully opposed by a broad coalition from general to commercial aviation interests, emergency services and environmentalists. Making the thing fly is the easy bit!

I'm not against this type of work, I just don't think people are being very realistic about (or more to the point: they are understating) what's actually required to get an affordable auto-pilot only 'air Uber' up and running, particularly one providing commercial services in urban environments. Piloted... maybe but there are still a lot of challenges to making something in that layout which works and can be certified and remains affordable/viable.

Of course (noise aside). I'm all for electric aircraft, in certain roles they're almost a no-brainer already (eg self sustaining gliders and trainer aircraft for operation in noise sensitive environments) but in other roles they'll likely remain a non-starter however good the batteries get (eg intercontinental airliners).

jk

That makes sense technically but I do wonder if the greater pubic awareness of and contact with aviation will apply commercial pressure to de(fossil)carbonise* aviation before legislative or commercial pressure comes to bear on shipping (problems with harmonising and therefore even meaningfully applying fuel taxes are going nowhere in either sector).

*we're going to need some new words

A look to the past (wind power) and present day racing/sporting tech (hydrofoils/kites) points to some options heavy shipping might have for relatively large energy savings. Even relatively conservative designs appear to offer very worthwhile savings in service https://en.wikipedia.org/wiki/E-Ship_1

jk

According to one of my climbing partners who works bringing investors into high-tech startups the objective is not a final commercial product but the knowhow amd patents. Even using the optimistic figures from the companies and leaving aside the other huge problems of whether they will be allowed they can only be toy for the super rich. Urban transport for the masses looks different!

Yeah but "ROLL UP, ROLL UP! Hover cars!"

Back in the real world for those of us who aren't risk-seeking financiers this is way more exciting http://www.alisport.com/?product=silent-2-electro-2

jk

Uber, self-driving cars etc, I might be out of a job before retirement age. 

Absolutely. I'm sure when I was a boy I was told we'd have flying cars by now! 

Possibly.

I read that the first autonomus vehicles will likely be taxis or other commercial vehicles. The reason being that they'll be expensive to buy, too expensive for the average punter. However if the vehicle eliminates a driver on a wage then it makes financial sense. My guess is a bit under a decade to start but who knows when they'll arrive in Falkirk [?].

There are autonomous tractors in fields, fork lift trucks in warehouses etc.. it is just a question of when we decide to put them in places irrational, error prone humans are. I think the tech will advance quickly and teething problems readily ironed out, society is in for a shock. The blacks cabs are complaining about uber, give it 20 years and there will only be a few uber cars with drivers. The rest will have gone. Diesel black cabs replaced with electric autonomous cars.

I'm not on a wage. Eliminating the driver? Hmmm... There's so many ways that won't work.

Do you have any idea what a taxi drivers job entails, other than the taking people from a to b part?

I'm sure you can programme a robot to say, "did you see the football last night?"....  "traffics bad today, I'll do my best guv".. 

When taxis are robotic all the information on traffic flow can be shared virtually. It would know the exact speed of traffic on all the roads in an instant and would make better decisions than the human who could only use historical, not live experience. 

Doors can open automatically for passengers.. special ramps for disabled, even a rack that opens out for baggage. They don't have be built or designed to look like our current vehicles. They could be built for purpose. 

Depends on your definition of autonomous, current tractors are supervised and a long, long way from true autonomy.

Given the helium is only 5.2 ppm in the atmosphere, unless we obtain a free source of energy, I don't think it will be practical to extract it from the atmosphere.

Given the very limited use we've seen so far has resulted in some deaths and an admission that the software currently available is incapable of coping with even the odd cyclist, I think we are further away from this than people like to think. Unless we want our streets to be no go areas for pedestrians and cyclists (of course there are quite a few people who do want that)

Jet-packs in my case.

Disagree.

Neon has an abundance of ~15 ppm and that is commercially extracted from the air - it is quite practical and 500,000 kg are produced by fractional distillation of air.

It’s just that it’s cheaper to get helium from fossil reserves.

Cost tends to determine whether it is viable to use. (currently neon 55 times more expensive than helium according to Wiki) Given that the concentration is 3 x less and the boiling point lower I would expect it to be quite a bit more expensive again to extract from air. 

It will improve. Think about 1999s tech..things move on.

But folk will still get run over, if people appear out of no where, you can't change  physics and stopping distances. Interesting moral points though, swerve and risk hitting other traffic, or hit pedestrian. All needs to be programmed in. 

As I said in my first post “Extraction is currently very expensive but there’s been no incentive to work on that problem.  “

My point was that (a) once fossil + helium reserves run out there is actually another source and (b) that other source is expensive but there has - so far - been no reason to optimise it.

No.  It doesn’t work like that.  Once the stuff that is more abundant is taken away, what’s left?  The Helium.

Unlike as commonly portrayed, there is no imminent crisis where we run out of helium - it just gets a lot more expensive.  Compared to the cost of the applications, it’s “Meh” for rocketry, “ouch” for medical imagers and the semiconductor industry and the end of party balloons.  Medical imaging is moving to higher temperature superconductors anyway.  Some clever rocketry stuff just can’t do without helium. I don’t know how critical it is as a purge gas for semiconductor fab.

For a minute I thought you were talking about human drivers..

It works exactly like that. 3 x more air to compress for the amount of helium got back. (compared to neon)

Sorry I should have been clearer.  I was referring to your comment on boiling point not abundance. To get gaseous helium, you just have to liquify the other stuff out of the air - helium’s lower boiling point enables this, it doesn’t make it more expensive.  Obviously you need to process more air than for neon...  The only thing the boiling point affects is the cost of liquefying the helium, and that depends on the amount of helium to be liquified and not the source so has no relevance I can see.

As I’ve said since my first post and as you seem intent on ignoring - this is a lot more expensive than getting it from the ground but my point was and is that helium is *not* going to run out and it can be liquified from air in large scale within the budget of some of its current applications, without any improvements in current technology.

This seems to be a realistic assessment of where we are with autonomous vehicles: https://www.technologyreview.com/s/613399/the-three-challenges-keeping-cars...

I'd imagine that designing an autonomous system for aircraft would be easier. Less to hit in the air.

..and another much bigger electric aircraft being developed: https://www.theengineer.co.uk/airlander-10-electric-propulsion/?cmpid=tenew...