The Anonymous Widower

Greener Planes Of The Future… Or Just Pretty Plans?

The title of this post, is the same as that of this article on the BBC.

  • It is a good survey of the way things will have to go for zero carbon aviation.
  • It shows designs from both Airbus and Boeing, with some more radical designs as well.

These are a few of my thoughts.

  • I think that we shan’t be seeing a too-radical design in the next decade, as it just wouldn’t fit the current airports.
  • But I can certainly envisage, aircraft running on liquid hydrogen.
  • There will be some outstanding aerodynamics.
  • Long-haul aircraft might just be upgraded current designs running on aviation biofuel.

I am certainly looking forward to taking a zero-carbon flight before 2030.

January 8, 2021 Posted by | Transport | , , , , , | Leave a comment

Shooter Urges Caution On Hydrogen Hubris

The title of this post is the same as that of an article in the January 2021 Edition of Modern Railways.

This is the first paragraph.

Vivarail Chairman Adrian Shooter has urges caution about the widespread enthusiasm for hydrogen technology. In his keynote speech to the Golden Spanner Awards on 27 November, Mr. Shooter said the process to create ‘green hydrogen’ by electrolysis is ‘a wasteful use of electricity’ and was skeptical about using electricity to create hydrogen to then use a fuel cell to power a train, rather than charging batteries to power a train. ‘What you will discover is that a hydrogen train uses 3.5 times as much electricity because of inefficiencies in the electrolysis process and also in the fuel cells’ said Mr. Shooter. He also noted the energy density of hydrogen at 350 bar is only one-tenth of a similar quantity of diesel fuel, severely limiting the range of a hydrogen-powered train between refuelling.

Mr. Shooter then made the following points.

  • The complexity of delivering hydrogen to the railway depots.
  • The shorter range available from the amount of hydrogen that can be stored on a train compared to the range of a diesel train.
  • He points out limitations with the design of the Alstom Breeze train.

This is the last paragraph.

Whilst this may have seemed like a challenge designed purely to promote the battery alternatives that Vivarail is developing, and which he believes to be more efficient, Mr. Shooter explained: ‘I think that hydrogen fuel cell trains could work in this country, but people just need to remember that there are downsides. I’m sure we’ll see some, and in fact we should because competition improves the breed.’

i think Mr. Shooter may have made several good points.

These are my thoughts.

Creating Green Hydrogen

I haven’t done an analysis of the costs of creating green hydrogen from electrolysis, but I have a feeling, that electrolysis won’t be the only way to create large amounts of carbon-free hydrogen, in a few years.

These methods are currently available or under development or construction.

  • The hydrogen tram-buses in Pau have a personal electrolyser, that provides hydrogen at 350 bar.
  • London’s hydrogen buses will be provided with hydrogen from an electrolyser at Herne Bay by truck. Will the trucks be hydrogen-powered?

Some industrial processes like the Castner-Kellner process create hydrogen as a by-product.

In Shell Process To Make Blue Hydrogen Production Affordable, I describe the Shell Blue Hydrogen Process, which appears to be a way of making massive amounts of carbon-free hydrogen for processes like steel-making and cement production. Surely some could be piped or transported by truck to the rail depot.

In ITM Power and Ørsted: Wind Turbine Electrolyser Integration, I describe how ITM Power and Ørsted plan to create the hydrogen off shore and bring it by pipeline to the shore.

Note.

  1. The last two methods could offer savings in the cost of production of carbon-free hydrogen.
  2. Surely, the delivery trucks if used, must be hydrogen-powered.
  3. The Shell Blue Hydrogen Process uses natural gas as a feedstock and converts it to hydrogen using a newly-developed catalyst. The carbon-dioxide is captured and used or stored.
  4. If the local gas network has been converted to hydrogen, the hydrogen can be delivered to the depot or filling station through that gas network.

I very much feel that affordable hydrogen can be supplied to bus, train, tram or transport depot. For remote or difficult locations. personal electrolysers, powered by renewable electricity, can be used, as at Pau.

Hydrogen Storage On Trains

Liquid hydrogen could be the answer and Airbus are developing methods of storing large quantities on aircraft.

In What Size Of Hydrogen Tank Will Be Needed On A ZEROe Turbofan?, I calculated how much liquid hydrogen would be needed for this ZEROe Turbofan.

I calculate that to carry the equivalent amount of fuel to an Airbus A320neo would need a liquid hydrogen tank with a near 100 cubic metre capacity. This sized tank would fit in the rear fuselage.

I feel that in a few years, a hydrogen train will be able to carry enough liquid hydrogen in a fuel tank, but the fuel tank will be large.

In The Mathematics Of A Hydrogen-Powered Freight Locomotive, I calculated how much liquid hydrogen would be needed to provide the same amount of energy as that carried in a full diesel tank on a Class 68 locomotive.

The locomotive would need 19,147 litres or 19.15 cubic metres of liquid hydrogen, which could be contained in a cylindrical tank with a diameter of 2 metres and a length of 6 metres.

Hydrogen Locomotives Or Multiple Units?

We have only seen first generation hydrogen trains so far.

This picture shows the Alstom Coradia iLint, which is a conversion of a Coradia Lint.

It is a so-so train and works reasonably well, but the design means there is a lot of transmission noise.

This is a visualisation of an Alstom Breeze or Class 600 train.

Note that the front half of the first car of the train, is taken up with a large hydrogen tank. It will be the same at the other end of the train.

As Mr. Shooter said, Alstom are converting a three-car train into a two-car train. Not all conversions live up to the hype of their proposers.

I would hope that the next generation of a hydrogen train designed from scratch, will be a better design.

I haven’t done any calculations, but I wonder if a lighter weight vehicle may be better.

Hydrogen Locomotives

I do wonder, if hydrogen locomotives are a better bet and easier to design!

  • There is a great need all over the world for zero-carbon locomotives to haul freight trains.
  • Powerful small gas-turbine engines, that can run on liquid hydrogen are becoming available.
  • Rolls-Royce have developed a 2.5 MW gas-turbine generator, that is the size of a beer-keg.

In The Mathematics Of A Hydrogen-Powered Freight Locomotive, I wondered if the Rolls-Royce generator could power a locomotive, the size of a Class 68 locomotive.

This was my conclusion.

I feel that there are several routes to a hydrogen-powered railway locomotive and all the components could be fitted into the body of a diesel locomotive the size of a Class 68 locomotive.

Consider.

  • Decarbonising railway locomotives and ships could be a large market.
  • It offers the opportunities of substantial carbon reductions.
  • The small size of the Rolls-Royce 2.5 MW generator must offer advantages.
  • Some current diesel-electric locomotives might be convertible to hydrogen power.

I very much feel that companies like Rolls-Royce and Cummins (and Caterpillar!), will move in and attempt to claim this lucrative worldwide market.

In the UK, it might be possible to convert some existing locomotives to zero-carbon, using either liquid hydrogen, biodiesel or aviation biofuel.

Perhaps, hydrogen locomotives could replace Chiltern Railways eight Class 68 locomotives.

  • A refuelling strategy would need to be developed.
  • Emissions and noise, would be reduced in Marylebone and Birmingham Moor Street stations.
  • The rakes of carriages would not need any modifications to use existing stations.

It could be a way to decarbonise Chiltern Railways without full electrification.

It looks to me that a hydrogen-powered locomotive has several advantages over a hydrogen-powered multiple unit.

  • It can carry more fuel.
  • It can be as powerful as required.
  • Locomotives could work in pairs for more power.
  • It is probably easier to accommodate the hydrogen tank.
  • Passenger capacity can be increased, if required by adding more coaches.

It should also be noted that both hydrogen locomotives and multiple units can build heavily on technology being developed for zero-carbon aviation.

The Upward Curve Of Battery Power

Sparking A Revolution is the title an article in Issue 898 of Rail Magazine, which is mainly an interview with  Andrew Barr of Hitachi Rail.

The article contains a box, called Costs And Power, where this is said.

The costs of batteries are expected to halve in the next years, before dropping further again by 2030.

Hitachi cites research by Bloomberg New Energy Finance (BNEF) which expects costs to fall from £135/kWh at the pack level today to £67/kWh in 2030 and £47/kWh in 3030.

United Kingdom Research and Innovation (UKRI) are predicting that battery energy density will double in the next 15 years, from 700 Wh/l to 1400 Wh/l in 2-35, while power density (fast charging) is likely to increase four times in the same period from 3 kW/kg to 12 kW/kg in 2035.

These are impressive improvements that can only increase the performance and reduce the cost of batteries in all applications.

Hitachi’s Regional Battery Train

This infographic gives the specification of Hitachi Regional Battery Train, which they are creating in partnership with Hyperdrive Innovation.

Note that Hitachi are promising a battery life of 8-10 years.

Financing Batteries

This paragraph is from this page on BuyaCar, which is entitled Electric Car Battery Leasing: Should I Lease Or Buy The Batteries?

When you finance or buy a petrol or diesel car it’s pretty simple; the car will be fitted with an engine. However, with some electric cars you have the choice to finance or buy the whole car, or to pay for the car and lease the batteries separately.

I suspect that battery train manufacturers, will offer similar finance models for their products.

This paragraph is from this page on the Hyperdrive Innovation web site.

With a standardised design, our modular product range provides a flexible and scalable battery energy storage solution. Combining a high-performance lithium-ion NMC battery pack with a built in Battery Management System (BMS) our intelligent systems are designed for rapid deployment and volume manufacture, supplying you with class leading energy density and performance.

I can envisage that as a battery train ages, every few years or so, the batteries will get bigger electrically, but still be the same physical size, due to the improvements in battery technology, design and manufacture.

I have been involved in the finance industry both as a part-owner of a small finance company and as a modeller of the dynamics of their lending. It looks to me, that train batteries could be a very suitable asset for financing by a fund. But given the success of energy storage funds like Gore Street and Gresham House, this is not surprising.

I can envisage that battery electric trains will be very operator friendly, as they are likely to get better with age and they will be very finance-friendly.

Charging Battery Trains

I must say something about the charging of battery trains.

Battery trains will need to be charged and various methods are emerging.

Using Existing Electrification

This will probably be one of the most common methods used, as many battery electric services will be run on partly on electrified routes.

Take a typical route for a battery electric train like London Paddington and Oxford.

  • The route is electrified between London Paddington and Didcot Junction.
  • There is no electrification on the 10.4 miles of track between Didcot Junction and Oxford.

If a full battery on the train has sufficient charge to take the train from Didcot Junction to Oxford and back, charging on the main line between London Paddington and Didcot Junction, will be all that will be needed to run the service.

I would expect that in the UK, we’ll be seeing battery trains using both 25 KVAC overhead and 750 VDC third rail electrification.

Short Lengths Of New Strategic Electrification

I think that Great Western Railway would like to run either of Hitachi’s two proposed battery electric trains to Swansea.

As there is 45.7 miles pf track without .electrification, some form of charging in Swansea station, will probably be necessary.

The easiest way would probably be to electrify Swansea station and perhaps for a short distance to the North.

This Google Map shows Swansea station and the railway leading North.

Note.

  1. There is a Hitachi Rail Depot at the Northern edge of the map.
  2. Swansea station is in South-West corner of the map.
  3. Swansea station has four platforms.

Swansea station would probably make an excellent battery train hub, as trains typically spend enough time in the station to fully charge the batteries before continuing.

There are other tracks and stations of the UK, that I would electrify to enable the running of battery electric trains.

  • Leeds and York, which would enable carbon-free London and Edinburgh services via Leeds and help TransPennine services. This is partially underway.
  • Leicester and East Midlands Parkway and Clay Cross North Junction and Sheffield – These two sections would enable EMR InterCity services to go battery electric.
  • Sheffield and Leeds via Meadowhall, Barnsley Dearne Valley and the Wakefield Line, which would enable four trains per hour (tph) between Sheffield and Leeds and an extension of EMR InterCity services to Leeds.
  • Hull and Brough, would enable battery electric services to Hull and Beverley.
  • Scarborough and Seamer, would enable electric services services to Scarborough and between Hull and Scarborough.
  • Middlesbrough and Redcar, would enable electric services services to Teesside.
  • Crewe and Chester and around Llandudno Junction station – These two sections would enable Avanti West Coast service to Holyhead to go battery electric.
  • Shrewsbury station – This could become a battery train hub, as I talked about for Swansea.
  • Taunton and Exeter and around Penzance, Plymouth and Westbury stations – These three sections would enable Great Western Railway to cut a substantial amount of carbon emissions.
  • Exeter, Yeovil Junction and Salisbury stations. – Electrifying these three stations would enable South Western Railway to run between London and Exeter using Hitachi Regional Battery Trains, as I wrote in Bi-Modes Offered To Solve Waterloo-Exeter Constraints.

We will also need fast chargers for intermediate stations, so that a train can charge the batteries on a long route.

I know of two fast chargers under development.

I believe it should be possible to battery-electrify a route by doing the following.

  • Add short lengths of electrification and fast charging systems as required.
  • Improve the track, so that trains can use their full performance.
  • Add ERTMS signalling.
  • Add some suitable trains.

Note.

  1. I feel ERTMS  signalling with a degree of automatic train control could be used with automatic charging systems, to make station stops more efficient.
  2. In my view, there is no point in installing better modern trains, unless the track is up to their performance.

January 4, 2021 Posted by | Energy, Hydrogen, Transport | , , , , , , , , , , , , , , , , , , , , , , , , , | 1 Comment

Faradair’s BEHA Hybrid Aircraft Boosted By Partnerships

The title of this post, is the same as that of this article on AINonline.

This is the introductory paragraph.

Faradair, the UK company developing a hybrid-electric short takeoff and landing aircraft for applications including regional airline service, on Thursday announced four new risk-sharing partners. Honeywell, MagniX, Cambridge Consultants, and Nova Systems, have all signed up to contribute to the development of the Bio Electric Hybrid Aircraft (BEHA), which is expected to enter service in 2026.

Some points from the article.

  • The aircraft is bio-electric as it is powered by a small gas-turbine generator, which drives a contra-rotating ducted fan, through a pair of electric-motors.
  • It has a quick-change interior, that can handle 18 passengers or five tonnes of cargo.
  • Range is given as 1,150 miles, with a service ceiling of 14,000 feet and a speed of up to 230 mph.

The Faradair web site gives other useful data.

  • Wingspan is 57 ft.
  • Length is 48 ft. 2 in.

The article also discloses an innovative way of marketing the aircraft, which looks to me, like a modern update to how the company I helped found; Metier Management Systems, leased Artemis project management computer systems, several decades ago.

Comparison With Eviation Alice

I must compare the Faradair BEMHA with the Eviation Alice.

The Alice can carry nine passengers.

  • It cruises at 276 mph.
  • Range is 620 miles
  • Service ceiling is 12,500 ft.
  • Wingspan is 52 ft. 11 in.
  • Length is 43.3 ft.

The Alice would appear to be slightly smaller, with a shorter range.

  • If you look at the pictures of the two aircraft on the Faradair and Eviation Alice web sites, you will see that they are radical designs.
  • The Eviation Alice is fully electric, whereas the Faradair BEHA has a hybrid engine based on a small gas turbine running on aviation biofuel.
  • Both aircraft use MagniX electric motors.
  • Both aircraft fit into defined segments of the aviation market.

I very much believe that we’ll be seeing more unusual zero-carbon and carbon-neutral aircraft designs in the next few years.

A few thoughts.

Battery-Electric or Gas Turbine?

The Eviation Alice is solely powered by a battery, whereas the Faradair BMHA uses a hybrid engine based on a small gas turbine running on aviation biofuel.

Airbus built an experimental aircraft called the Airbus E-Fan X. This aircraft was to have used a gas-turbine and a battery. The aircraft was cancelled because of the Covid-19 pandemic.

So Faradair seem to be going a similar route to Airbus.

The AINonline article says this about Honeywell’s involvement.

Honeywell will support Faradair in producing a turbogenerator based on its gas turbine and generator technologies that is able to run on sustainable aviation fuel. The U.S. aerospace group will also contribute to other systems for BEHA, including avionics and flight controls.

According to Wikipedia, Honeywell certainly have lots of experience of small gas-turbine engines. They also make large numbers of auxiliary power units for aircraft.

The big disadvantage of the battery approach, is surely the weight of the battery, which needs to be large to have enough energy for the flight.

  • But electric power also restricts the aircraft to airports with recharging facilities. This must reduce the flexibility of the aircraft.
  • And also what happens after a diversion caused by weather, a passenger becoming unwell or some other circumstance, where the aircraft ends up at an airport with no handling for electric aircraft?

But with an aircraft that only needs sustainable aviation fuel, it can be filled up from a bowser used for small airliners and business jets.

If you want to be zero-carbon perhaps it would be better to fuel the gas-turbine with hydrogen.

Airbus seem to have come to that conclusion with their future plans, that I wrote about in ZEROe – Towards The World’s First Zero-Emission Commercial Aircraft.

I have a feeling that both Airbus and Faradair have shown, that to get enough range and for convenience, sustainable aviation fuel or hydrogen is better.

Nine Or Eighteen Seat?

Regulation has made nine- and nineteen-seats into niche markets and each developer is concentrating on a particular market.

  • An airline that uses small airliners like Loganair, actually has aircraft in both groups.
  • I suspect other airlines have similar mixed fleets.
  • Cape Air, who are the lead customer for the Alice, only fly nine-seat aircraft.

The customer has a choice depending on the size of aircraft he needs.

Short Take-Off And Landing Capability

I have flown as a passenger several times in small airliners with a capacity of up to nineteen seats.

  • Usually, they have been in a Cessna Caravan or Britten Normand Islander.
  • In a couple of cases, the trip has involved a take-off or landing on a short or grass runway.
  • Additionally, I have over a thousand hours in command of a Cessna 340, where I used a lot of short runways.

I would feel that as a lot of small airports have short runways, that a short take-off and landing capability would be a necessity for a small airliner.

Versatility

This Faradair press release is dated December 17th, 2020.

This paragraph details the aircrafts versatility.

The ambition is to deliver an initial portfolio of 300 Faradair®-owned BEHAs between 2026-2030, in the largest proof of concept air mobility programme ever created. Of these, 150 aircraft will be built in firefighting configuration, 75 as quick change (QC, passenger to cargo) aircraft, deployed at general  aviation airfields globally, and 50 as pure freighters. The final 25 aircraft will be demonstrated in non-civilian government roles, including logistics, border and fisheries patrol, and drug interdiction.

Note.

I particularly like the quick-change variant.

As 125 aircraft can be used for freighters, has one of the large parcel carriers expressed an interest?

I must admit, I’m surprised that 150 aircraft will be needed in a firefighting configuration.

To be continued…

 

 

December 18, 2020 Posted by | Transport | , , , , , , , | 3 Comments

Flying A Hydrogen-Powered ZEROe

The ZEROe Turbofan and the ZEROe Turboprop, both have a large liquid hydrogen tank in the rear fuselage.

Will this affect the handling characteristics of the aircraft and make them difficult to fly?

The balance will probably be different as the weight of the tank with a full load of hydrogen could be significant. Think putting two bags of cement in the back of a typical hatchback car.

But all Airbuses should handle the different feel easily.

The three main flight control surfaces, by which pilots control the aircraft; ailerons, elevator and rudder are not actually controlled directly by the pilots, but by computers that are connected between the controls the pilot uses and the control surfaces themselves.

This means that control methods, which are unavailable on an aircraft with traditional controls, can be used to fly the aircraft.

So this means that any problems caused by the heavy weight in the rear of the fuselage can be solved.

 

 

September 25, 2020 Posted by | Computing, Hydrogen, Transport | , , , , , | Leave a comment

Could An A320 neo Be Rebuilt As A ZEROe Turbofan?

This post is a follow-up to ZEROe – Towards The World’s First Zero-Emission Commercial Aircraft.

I spent a lot of time yesterday, looking at YouTube videos of the following.

  • Airbus A320 aircraft
  • Airbus A 320 neo aircraft
  • Airbus’s proposed ZEROe Turbofan aircraft

I also captured these profiles from the Airbus web site, of three members of the new Airbus A 320 neo family and the current Airbus A 320 ceo.

A 319 neo – Length – 33.84 metres – Max Passengers – 160

A 320 neo – Length 37.57 metres – Max Passengers – 194

A 321 neo – Length 44.51 metres – Max Passengers – 244

A 320 ceo – Length 37.57 – Max Passengers – 180

Note.

  1. The links on each variant lead to Airbus’s on-line specification.
  2. All three variants have a wing-span of 35.8 metres and a height of 11.76 metres.
  3. All variants have sharklets or blended winglets to improve awrodynamic efficiency.
  4. There are different door, cargo door and window layouts on all three variants.
  5. The cockpits, tail and wings look similar.

This capture from an Airbus video, shows the profile of the proposed ZEROe Turbofan.

Note, that the ZEROe Turbofan looks more streamlined than the A 320 neo family, with a redesigned nose and more swept-back tailfin and sharklets.

These are my thoughts on the current A 320 neo family and their relationship with the ZEROe Turbofan.

Focus On Commonality

For each variant on the Airbus web site, there is a section with this title. This is the first sentence for the A 320 neo.

Due to its 95 per cent airframe commonality with the A320ceo (current engine option) version, Airbus’ A320neo jetliner fits seamlessly into existing A320 Family fleets worldwide – which is a key factor for the company’s customers and operators.

Will Airbus follow this philosophy with the ZEROe Turbofan?

If it worked between the changeover between the existing A 320 fleets and the A 320 neo fleets, why change the policy?

The Cockpits

The cockpits of the A 320 neo and the A 320 ceo seem to have a similar profile, but the cockpit of the ZEROe Turbofan seems to have been reprofiled.

In ZEROe – Towards The World’s First Zero-Emission Commercial Aircraft, I showed these front on views of the cockpits of the ZEROe Turboprop and ZEROe Turbofan.

I questioned if the two cockpits were related.

  • A single cockpit for both aircraft would surely ease manufacture, maintenance and pilot training.
  • I’m no aerodynamicist, but it certainly looks that the new cockpit will reduce drag and fuel consumption.

Although the cockpit, appears to be being used in the ZEROe for the first time, I would expect it is already under development and might feature in any later version of the A 320 neo.

The Fuselages

The fuselage width for both the A 320 neo family and the A 320 ceo are all 3.95 metres, with a maximum cabin width of 3.70 metres.

I would expect that the ZEROe Turboprop and the ZEROe Turbofan will also use this width.

Airbus use a design called Cabin-Flex to get the most out of the interior space in the A 320 neo. This paragraph is from the Wikipedia section, that is entitled Cabin-Flex.

By permanently replacing the second door pair in front of the wing (R2/L2) with a new second pair of overwing exits, the capacity of the A321neo is increased from 220 seats to 240 seats and fuel efficiency per seat is increased by 6%, exceeding 20% together with the new engines and the sharklets. The modifications should weigh 100 kg more.[82] Initial A321neos have the A321ceo exit door configuration with four exit door pairs until the Airbus Cabin-Flex (ACF) layout can be selected.

After reading the whole section, it looks to me, that the A 320 neo fuselage is designed, to be all things to all airlines and doors and seats can be arranged to fit any requirements.

In the ZEROe Turbofan, there is a large liquid hydrogen tank behind the rear pressure bulkhead, which could be brought forward a bit to give more space and hydrogen capacity.

I suspect there will be a lot of commonality between the fuselage of the A 320 neo family and that of a ZEROe Turbofan.

I spent a lot of time, as a child building Airfix models of aircraft and it may be too much of a simplification to think of these carbon-composite airliners, as giant Airfix models.

But I wouldn’t be surprised that just like the previous generation of aluminium airliners, they can be remanufactured into something different, just like British Airways Tristars, ended up as tanker-aircraft for the RAF.

I wouldn’t be surprised to find, that later A 320 neo fuselages will be able to be remanufactured into fuselages for ZEROe Turbofans.

Comparing The Fuselages Of The A 320 ceo, A 320 neo And ZEROe Turbofan

These are the three fuselage profiles.

A 320 ceo

A 320 neo

ZEROe Turbofan

Aircraft balance on the wings, which if I remember what little I know about aircraft aerodynamics and design, apply their lift forces to the centre of gravity of the aircraft.

I know that the profile of the ZEROe is to a different scale, but three things are apparent.

  • The windows at the rear don’t go as far back, as they do in the two existing designs. But then there is no need for windows around the hydrogen tank.
  • The hydrogen tank could be as long as a quarter of the length of the fuselage.
  • The front section of the aircraft appears longer.

The longer front section would balance the weight of the hydrogen tank.

The passengers would also help to balance the weight of the tank, by being placed further forward.

There must be the possibility of creating a larger capacity and longer range variant of the ZEROe design, by adding a larger hydrogen tank and further stretching the nose.

Airbus have been stretching these designs for years, so I suspect that they have plans for a large number of possible variants of the ZEROe Turbofan.

According to the Wikipedia entry for the A 320 neo family, there are already five civil versions of the A 320 neo; A 319 neo, A 320 neo, A 321 neo, A 321LR and A 321XLR, plus corporate and military versions.

Add in the Cabin-Flex interior and the various A320s and the ZEROe to come, must be one of the most flexible transport systems in history.

The Tailplanes

As they are of the same height and look similar, the tail sections of the A 320 neo and A 320 ceo families could be almost identical, but the tail section of the ZEROe Turbofan appears to be slightly more swept-back and perhaps more aerodynamic.

As the ZEROe Turbofan, also appears to have had a nose-job, I would suspect that Airbus have a redesigned fuselage in the works to squeeze more fuel-efficiency out of this family of already very frugal aircraft. Could this feature the more aerodynamic tailplane?

Could this advanced fuselage feature in a later version of the A 320 neo?

I also feel, that the functionality of the tailplane on the ZEROe Turbofan will need to be little different to that on the earlier planes.

  • The plane is still powered by two turbofan engines on the wings.
  • Rudder forces, with an engine failure on one side, will still be the same.

The big difference will be that the fuel is at the back of the fuselage rather than in the wings, which will affect the balance.

Will this effect the design of the tailplane? I don’t think it will in a large way, as Airbus seem to have lengthened the nose to compensate.

The Wings

All the wings with sharklets for the A 320 neo family and the A 320 ceo have the same wingspan of 35.8 metres, so I would expect they are all substantially similar.

But there is one big difference in that the wings of the conventionally-powered aircraft are full of fuel.

This would probably mean that much of the wing stresses in the ZEROe Turbofan would be like an A 320 neo flying with little fuel in the wing tanks. As some aircraft in the A320 neo family have fuselage tanks, Airbus can even test the wing forces and handling in a real aircraft.

But it does look that Airbus will have little trouble designing, building and certifying the wing of a ZEROe Turbofan.

There is a minor difference in that the sharklets for the ZEROe Turbofan are more extreme.

But then as I said earlier, is there a new more aerodynamic airframe for the A 320 neo in the works?

Conclusion

I very much feel that there will be a route to convert some or all of the A 320 neo aircraft to hydrogen power.

 

 

September 25, 2020 Posted by | Hydrogen, Transport | , , , , , | Leave a comment

ZEROe – Towards The World’s First Zero-Emission Commercial Aircraft

The title of this post, is the same as that of this Press Release from Airbus.

This is the introductory paragraph.

At Airbus, we have the ambition to develop the world’s first zero-emission commercial aircraft by 2035. Hydrogen propulsion will help us to deliver on this ambition. Our ZEROe concept aircraft enable us to explore a variety of configurations and hydrogen technologies that will shape the development of our future zero-emission aircraft.

Overall, the Press Release discloses a lot and gives details of three different aircraft, which are shown in this Airbus infographic.

Discover the three zero-emission concept aircraft known as ZEROe in this infographic. These turbofan, turboprop, and blended-wing-body configurations are all hydrogen hybrid aircraft.

I have some thoughts that apply to all three concepts.

Hydrogen Hybrid Power

The Press Release says this about the propulsion systems for the three aircraft.

All three ZEROe concepts are hydrogen hybrid aircraft. They are powered by hydrogen combustion through modified gas-turbine engines. Liquid hydrogen is used as fuel for combustion with oxygen.

In addition, hydrogen fuel cells create electrical power that complements the gas turbine, resulting in a highly efficient hybrid-electric propulsion system. All of these technologies are complementary, and the benefits are additive.

There is a Wikipedia entry which is entitled Hydrogen Fuel, where this is said.

Once produced, hydrogen can be used in much the same way as natural gas – it can be delivered to fuel cells to generate electricity and heat, used in a combined cycle gas turbine to produce larger quantities of centrally produced electricity or burned to run a combustion engine; all methods producing no carbon or methane emissions.

It looks like the aircraft will be powered by engines that are not too different to the current engines in today’s aircraft.

This must be a big advantage, in that much of the research done to improve the current gas-turbine powered by aviation fuel will apply.

Liquid Hydrogen

It appears all three aircraft will use liquid hydrogen.

Liquid Hydrogen Storage

I believe the major uses for hydrogen will be aircraft, buses, cars, rail locomotives and multiple units and heavy trucks.

All will need efficient storage of the hydrogen.

Some applications, will use it in liquid form, as it is a more dense form, but it will need to be kept cold.

As aviation will probably be the most demanding application, will it drive the storage technology?

Oxygen

This will be atmospheric oxygen, which is used by any combustion engine.

Fuel Cells

Will the fuel cells be used to provide power for the plane’s systems, rather than to power the aircraft?

Most airlines do this with an auxiliary power unit or APU, which is just a small gas-turbine engine with a generator. The A 320 family use one made by Pratt & Whitney, which is described on this page of their web site. It is the third one on the page and is called a APS3200. This is said about its function.

Pratt & Whitney APS3200 is the Airbus baseline APU of choice for the Airbus A320 family of aircraft. It is designed to meet performance and environmental requirements for modern day, single-aisle aircraft. The APU comprises a single-shaft, fixedspeed, high-pressure ratio core driving a load compressor that provides bleed air for cabin conditioning and main engine starting, concurrent with 90kVA of electrical power.

The APU is usually located in the tail.

In the ZEROe family will there be a fuel-cell powered compressor to provide bleed air for cabin airconditioning and main engine starting?

Slippery Aerodynamics

Airbus seem to be the masters of slippery aerodynamics, which will help make the planes very fuel efficient.

Lightweight Composite Structures

Like the latest Airbus airliners, these planes will be made from lightweight composite structures and I wouldn’t be surprised to see weight saving in other parts of the aircraft.

Carbon Emissions And Pollution

There will be no carbon dioxide produced, as where’s the carbon in the fuel?

But there could be small amounts of the oxides of nitrogen produced, by the combustion, as nitrogen will be present from the air.

Noise

As the aircraft are powered by gas-turbine engines, there will be some noise.

The Mathematics Of Hydrogen-Powered Aviation

The mathematics for these three aircraft must say, that the designs are feasible.

Otherwise Airbus wouldn’t have published a detailed Press Release, only for it to be torn to pieces.

Pressures Driving Aviation In The Next Ten Years

Aviation will change in the text ten years and it will be driven by various competing forces.

Environmental Issues

Pollution, Carbon Emissions and Noise will be the big environmental issues.

Hydrogen will go a long way to reducing the first two issues, but progress with noise will generally be made by better engineering.

COVID-19 And Future Pandemics

These could have a bigger effect, as to make flying safe in these troubled times, passengers will need to be given more space.

But I do wonder, if there is an administrative solution, backed up, by innovative engineering.

Could a very quick test for COVID-19, that would stop infected passengers boarding, coupled with high quality automatic cleaning and air purification, ensure that passengers didn’t get infected?

Entry Into Service

Airbus are quoting 2035 in the Press Release and this YouTube video.

Is that ambitious?

Thoughts On The Three Designs

My thoughts on the three designs, follow in the next three sections.

The ZEROe Turboprop

This is Airbus’s summary of the design for the ZEROe Turboprop.

Two hybrid hydrogen turboprop engines, which drive the six bladed propellers, provide thrust. The liquid hydrogen storage and distribution system is located behind the rear pressure bulkhead.

This screen capture taken from the video, shows the plane.

It certainly is a layout that has been used successfully, by many conventionally-powered aircraft in the past. The De Havilland Canada Dash 8 and ATR 72 are still in production.

The Turboprop Engines

If you look at the Lockheed-Martin C 130J Super Hercules, you will see it is powered by four Rolls-Royce AE 2100D3 turboprop engines, that drive 6-bladed Dowty R391 composite constant-speed fully-feathering reversible-pitch propellers.

These Rolls-Royce engines are a development of an Allison design, but they also form the heart of Rolls-Royce’s 2.5 MW Generator, that I wrote about in Our Sustainability Journey. The generator was developed for use in Airbus’s electric flight research program.

I wouldn’t be surprised to find the following.

  • , The propulsion system for this aircraft is under test with hydrogen at Derby and Toulouse.
  • Dowty are testing propellers suitable for the aircraft.
  • Serious research is ongoing to store enough liquid hydrogen in a small tank that fits the design.

Why develop something new, when Rolls-Royce, Dowty and Lockheed have done all the basic design and testing?

The Fuselage

This screen capture taken from the video, shows the front view of the plane.

From clues in the picture, I estimate that the fuselage diameter is around four metres. Which is not surprising, as the Airbus A320 has a height of 4.14 metres and a with of 3.95 metres.

So is the ZEROe Turboprop based on a shortened Airbus A 320 fuselage?

As the aircraft has a capacity of less than a hundred passengers and an Airbus A320 has six-abreast seating, could the aircraft have sixteen rows of seats.

With the seat pitch of an Airbus A 320, which is 81 centimetres, this means just under thirteen metres for the passengers.

The Technical Challenge

I don’t feel there are any great technical challenges in building this aircraft.

  • The engines appear to be conventional and could even have been more-or-less fully developed.
  • The fuselage could be a development of an existing design.
  • The wings and tail-plane are not large and given the company’s experience with large composite structures, they shouldn’t be too challenging.
  • The hydrogen storage and distributing system will have to be designed, but as hydrogen is being used in increasing numbers of applications, I doubt the expertise will be difficult to find.
  • The avionics and other important systems could probably be borrowed from other Airbus products.

Given that the much larger and more complicated Airbus A380 was launched in 2000 and first flew in 2005, I think that a prototype of this aircraft could fly around the middle of this decade.

The Market Segment

It may seem small at less than a hundred seats, but it does have a range of greater than a 1000 nautical miles or 1150 miles.

Consider.

  • It compares closely in passenger capacity, speed and range, with the De Havilland Canada Dash 8/400 and the ATR 72/600.
  • The ATR 72 is part produced by Airbus.
  • The aircraft is forty percent slower than an Airbus A 320.
  • It is a genuine zero-carbon aircraft.
  • It looks like it could be designed to have a Short-Takeoff-And Landing (STOL) capability.

On the other hand, a lot of busy routes, like London and Edinburgh and Berlin and Munich are less than or around 400 miles.

These short routes are being challenged aggressively by the rail industry, as over this sort of distance, which typically takes four hours by train, rail has enough advantages, that passengers may choose not to fly.

Examples of cities with a range of between 400 and 1000 miles from London include.

  • Berlin – 571 miles
  • Cork – 354 miles
  • Inverness – 445 miles
  • Lisbon – 991 miles
  • Madrid – 781 miles
  • Palma – 835 miles
  • Rome – 893 miles
  • Stockholm – 892 miles
  • Warsaw – 900 miles

This aircraft would appear to be sized as an aircraft, that can fly further than passengers are happy to travel by train. But because of its cruising speed, the routes, where it will be viable would probably be limited in duration.

But important routes to, from and between secondary locations, like those that used to be flown by FlyBe, would surely be naturals for this aircraft.

It looks to be an aircraft that could have a big future.

The ZEROe Turbofan

This is Airbus’s summary of the design.

Two hybrid hydrogen turbofan engines provide thrust. The liquid hydrogen storage and distribution system is located behind the rear pressure bulkhead.

This screen capture taken from the video, shows the plane.

ZEROeTurbofan

This screen capture taken from the video, shows the front view of the plane.

The aircraft doesn’t look very different different to an Airbus A320 and appears to be fairly conventional. It does appear to have the characteristic tall winglets of the A 320 neo.

The Turbofan Engines

These would be standard turbofan engines modified to run on hydrogen, fuelled from a liquid hydrogen tank behind the rear pressure bulkhead of the fuselage.

If you want to learn more about gas turbine engines and hydrogen, read this article on the General Electric web site, which is entitled The Hydrogen Generation: These Gas Turbines Can Run On The Most Abundant Element In the Universe,

Range And Performance

I will compare range, performance and capacity with the latest Airbus A 320.

ZEROe Turbofan

  • Range – 2300 miles
  • Cruising Speed – Mach 0.78
  • Capacity – < 200 passengers

Airbus A 320

  • Range – 3800 miles
  • Cruising Speed – Mach 0.82
  • Capacity – 190 passengers

There is not too much difference, except that the A 320 has a longer range.

The Cockpits Of The ZEROe Turboprop And The ZEROe Turbofan

This gallery puts the two cockpit images together.

Are they by any chance related?

Could the controls and avionics in both aircraft be the same?

A quick look says that like the Boeing 757 and 767, the two planes have a lot in common, which may enable a pilot trained on one aircraft to fly the other, with only minimal extra instruction.

And would it be a simple process to upgrade a pilot from an A 320 to a ZEROe Turbofan?

The Fuselages Of The ZEROe Turboprop And The ZEROe Turbofan

I estimated earlier that the fuselage of the Turboprop was based on the cross-section of the A320.

Looking at the pair of front views, I wouldn’t be surprised to find, that both aircraft are based on an updated A 320 fuselage design.

Passengers and flightcrew would certainly feel at home in the ZEROe Turbofan, if internally, it was the same size, layout and equipment as a standard A 320 or more likely an A 320 neo.

The Market Segment

These are my thoughts of the marketing objectives of the ZEROe Turbofan.

  • The cruising speed and the number of passengers are surprisingly close, so has this aircraft been designed as an A 320 or Boeing 737 replacement?
  •  I suspect too, that it has been designed to be used at any airport, that could handle an Airbus A 320 or Boeing 737.
  • It would be able to fly point-to-point flights between most pairs of European or North American cities.

It would certainly fit the zero-carbon shorter range airliner market!

In fact it would more than fit the market, it would define it!

The ZEROe Blended-Wing Body

This is Airbus’s summary of the design.

The exceptionally wide interior opens up multiple options for hydrogen storage and distribution. Here, the liquid hydrogen storage tanks are stored underneath the wings. Two hybrid hydrogen turbofan engines provide thrust.

This screen capture taken from the video, shows the plane.

This aircraft is proposed to have the same performance and capacity as the ZEROe Turbofan, which includes a 2000 nautical mile plus range.

The only other aircraft with a similar shape is the Northrop Grumman B-2 Spirit or Stealth Bomber. This is not a fast aircraft, but it is able to fly at an altitude of 50,000 ft, which compares to the 60,000 ft of Concorde and the 43,000 ft of an Airbus A 380.

I wonder, if the blended-wing body is designed to fly very high at around the 60,000 ft, which was Concorde territory.

It would only be doing 515 mph and would be well below the speed of sound.

So what is the point on going so high?

The air is very thin and there is a lot less drag.

It is also worth reading Wikipedia on the design of flying wings.

It might be possible to fly much further than 2000 nautical miles. After all Airbus did put in a plus sign!

Is this aircraft the long-distance aircraft of the three?

Extending The Range

I do wonder, if the engines in these aircraft could be capable of running on both hydrogen and aviation biofuel.

As the ZEROe Turboprop and the ZEROe Turbofan planes have empty wings, which in a conventional aircraft would hold fuel, could the space be used to hold aviation biofuel to extend the range?

Certification Of The Planes

The ZEROe Turboprop and ZEROe Turbofan are aircraft, where a lot of the design will already have been proven in previous aircraft, so will probably be much less onerous to approve, than the blended-wing body design.

Conclusion

It looks to me, that Airbus have designed three aircraft to cover the airline market.

I also feel that as the ZEROe Turboprop and ZEROe Turbofan, appear to have conventional airframes, that they could be delivered before 2035.

If I’m right, that the blended-wing body is a high flyer, it will be a ride to experience, travelling at that height all the way to New York.

September 22, 2020 Posted by | Hydrogen, Transport | , , , , , , , , , , , | 5 Comments

Distributed Propulsion ‘Maybe The Only Means’ For Small Electric Flight Progress

The title of this post, is the same as that of this article on the Institute of Mechanical Engineers web site.

If you want to fly again, then this article offers pointers to how you might do it.

The E-Fan X Airliner

It gives this latest information on the E-Fa X airliner being tested by Rolls-Royce and Airbus.

Amid the strain of the Covid-19 pandemic, Rolls-Royce and Airbus cancelled flight tests of their E-Fan X airliner, a promising project that could have provided vital data on issues such as thrust management and electric systems at altitude.

Does that mean cancelled or scrapped?

2.5 MW From A Beer Keg-Sized Generator

This paragraph could be important.

“Among the many great achievements from E-Fan X has been the generator – about the same size as a beer keg – but producing a staggering 2.5MW,” said Vittadini’s Rolls-Royce counterpart Paul Stein. “That’s enough power to supply 2,500 homes and fully represents the pioneering spirit on this project.”

This picture shows a Class 66 locomotive.

The locomotive has a 2,460 kW diesel engine and an electric transmission.

I just wonder, if Rolls Royce’s high-powered small generator could replace the large, noisy and smelly diesel engines in these locomotives.

If the technology worked there are 455 of the noisy locomotives.

Snowballing Improvements

The article has a section with this title and it talks about how electric power may lead to other advantages.

Conclusion

Electric aircraft are more promising, than many think!

 

July 17, 2020 Posted by | Energy, Transport | , , , , | 1 Comment

Airbus On Electric Flight

This page on the Airbus web site is all about electric flight.

This paragraph greets you.

Today, zero-emission flight is closer to reality than ever. Electric and hybrid-electric propulsion is rapidly revolutionising mobility technologies across industries, from automotive to marine. And the aviation industry is no exception. Airbus is committed to developing, building and testing electric and hybrid-electric future technology that will enable the aviation industry to significantly reduce the CO2 emissions of commercial aircraft.

A read of the whole section is recommended.

A lot of technology will need to be improved even to get say a 60-seat airliner, with a 500 mile range.

  • Design-changing efficient aerodynamics.
  • Lightweight, strong structures.
  • Efficient zero-carbon propulsion systems.
  • Batteries with a much higher energy capacity per kilogram of battery weight.

It’s a tough ask, but I believe it is possible!

We might even see some very unusual ideas. And some proven ones.

Catapults

Naval fighters are usually literally thrown into the air from aircraft carriers using aircraft catapults, which traditionally were steam-powered. Gliders are often towed into the air using a rope.

So could something similar be used to accelerate the aircraft to flying speed?

Taxiing And Take-Off Using A Tug

All taxiing would use a battery-electric or hybrid-hydrogen-electric tug to minimise use of energy from the plane’s batteries.

Could the tug be combined with charging and a vehicle to handle the catapult launch?

  • A fully-charged tug would meet incoming aircraft and tow them to the terminal.
  • The aircraft would use the tug for power, if it was low.
  • At the terminal, the tug and aircraft would be charged, during passenger unloading and loading.
  • On the taxi to the runway, all power would be provided by the tug.
  • The catapult system, would attach to the tug on take-off.
  • Once take-off speed was achieved, the aircraft would disconnect and climb away under its own power.

All the power for acceleration to take-off speed would be provided on the ground and the aircraft wouldn’t have to carry it.

Energy Calculations For An Airbus 220-100

The smallest Airbus aircraft is the A220-100, which has the following specification.

  • Passengers – 135
  • Maximum Take-Off Weight – 63.1 tonnes
  • Cruise speed – 871 kph
  • Take-off speed – 220 kph (estimated)
  • Ceiling – 41,000 ft.

Note that the design cruise speed of the nine-seat electric Eviation Alice is 482 kph at 10,000 ft.

Using Omni’s Kinetic Energy Calculator, the following values are obtained.

  • 220 kph – 32.7 kWh
  • 482 kph – 157 kWh
  • 981 kph – 513 kWh

As the kinetic energy is proportional to the square of the speed, I would expect that a small electric airliner would have a cruise speed slower than current airliners.

I would expect that Alice’s cruise at 482 kph and 10,000 ft., could have been chosen to get a decent range for the maximum size of battery.

The aircraft will also have to be given potential energy in the climb.

Using Omni’s Potential Energy Calculator, the following values are obtained.

  • 5,000 ft. – 262 kWh
  • 10,000 ft. – 524 kWh
  • 41,000 ft. – 2148 kWh

I would expect a small electric airliner  would fly a lot lower.

A 135-seat electric airliner, which is the same weight as an Airbus 220-100 and cruising at 482 kph and 10,000 feet would need the following energy to establish itself in the cruise.

  • Kinetic energy – 157 kWh
  • Potential energy – 524 kWh
  • Take-off energy at 220 kph – 32.7 kWh

Which gives a total of 681 kWh.

It should be noted that both the kinetic and potential energies are proportional to the maximum take-off weight. Assuming that take-off weight would be proportional to the number of passengers, rough estimates for the battery size needed.

  • 25 – 126 kWh
  • 50 – 252 kWh
  • 75 – 378 kWh

As Wikipedia says the smaller nine-seater Eviation Alice has a 900 kWh battery, I feel that at least a fifty passenger electric airliner is possible.

Very Efficient Aerodynamics

One of the biggest losses of energy will be due to less-than-perfect aerodynamics, with vortices, eddies and skin friction wasting precious energy.

Look at the pictures on the Internet of the Eviation Alice and you’ll see a strange aircraft.

  • A very pointed nose.
  • Two propellers at the wing-tips.
  • A third propeller at the tail.
  • I suspect, all the propellers are placed to get the most out of the power.

When Alice is cruising, her energy consumption will be minimal, so that the maximum range for a given battery size can be obtained.

Any electric airliner will draw on all the aerodynamic tricks in the book.

Efficient Flight Profiles

The longest flight, that I ever did in my Cessna 340A was from Southend to Naples.

  • Before take-off at Southend, the fuel bowser followed me to the end of the runway to give me a last-second top-up.
  • I travelled across France on a beautifully-clear day and the accommodating Lyon ATC allowed me to fly at 19,500 feet all the way to French Coast at Nice.
  • The French then decided that, as I was happy at that height, they would hand me over to the Italians without a change of level.
  • So I flew down the Italian coast past Genoa and Rome at 180 knots, with spectacular views all the way.
  • The Italians, then used radar to vector me on to final approach at Naples.

I reckon, I had flown nearly a thousand miles in if I remember correctly about six hours.

But it was a very efficient flight profile to get the range.

  • I took the maximum about of fuel, I could carry.
  • I climbed as fast as possible to an efficient cruising level.
  • I cruised at an efficient speed.
  • I used very little fuel on the descent and landing into Naples.

I certainly was pleased, that I had about another hour’s fuel left, when I arrived in Naples.

Electric aircraft will probably always fly efficient profiles, to get the maximum range. But they will all be calculated by the plane’s computer system.

Most Aircraft Are Heaviest At Take-Off

This is because they burn fuel in the engines, as they fly along.

But a full battery weighs the same as an empty one, so the electric aircraft will have the same flying characteristics in all stages of the flight.

This could have design and operational advantages.

Hybrid Propulsion

Some electric aircraft designs are hybrid, with both battery and turboprop power.

It still cuts carbon emissions and may give better performance.

Fuel created from biomass can also be used.

Conclusion

I expect to fly in an Aubus battery-electric short-haul plane between London and Geneva by 2030.

But I’m certain, I’ll fly before that in an electric aircraft.

 

 

 

 

 

May 20, 2020 Posted by | Transport | , , , , | 4 Comments

Get Set For Max Return, Says Boeing

The title of this post is the same as this article in The Times.

This is the introductory paragraph.

Boeing is to fire up its 737 Max production line by May as it seeks to return the aircraft to service by the middle of the year.

Two points from the article.

  • Some suppliers have been asked to start shipping parts from April.
  • Boeing’s share price has risen, by 34.3%

But given the shadow over air travel caused by COVID-19, is restarting production a wise move?

I certainly don’t trust the Boeing 737 MAX!

But then if you live in London, I don’t think, you will need to fly in one, as there are a good selection of short haul trains and airlines that fly the smaller Airbuses.

I probably won’t fly short-haul again, until an airline starts flying electric aircraft.

March 26, 2020 Posted by | Transport | , , , | 3 Comments

Opinion: Why Aviation Needs to Go Green, and How

The title of this post is the same as that of this article on Aeronautics Online.

Read the article and especially what it says about the Wright Electric Jet.

This is a paragraph from Wikipedia, talking about co-operation between Wright Electric and easyJet.

In September 2017, UK budget carrier EasyJet announced it was developing an electric 180-seater for 2027 with Wright Electric. Wright Electric built a two-seat proof-of-concept with 272kg (600lb) of batteries, and believes that batteries can be scaled up with substantially lighter new battery chemistries: a 291 nautical mile (540km) range would suffice for 20% of Easyjet passengers. Wright Electric plans to develop a 10-seater and eventually an at least 120 passengers single-aisle, short-haul airliner and targets 50% lower noise and 10% lower costs.

I would assume, that the plane also emits a lot less CO2 and other pollutants.

I would assume that the plane will be built by using the best of these technologies.

  • Aerodynamics
  • Lightweight structures
  • Electric Motors
  • Batteries
  • Electronics and avionics.

But I also believe that designing an electric aircraft could be a very different process to a conventional one.

There Is No Fuel

Consider.

  • Fuel is a high proportion of the weight of an airliner on take-off.
  • There are a lot of complicated systems to pump fuel to the engines and also from tank to tank to trim or balance the aircraft
  • When a conventional airliner takes off, it is much heavier than when it lands, as fuel has been burned.
  • Fuel is dangerous in a heavy landing or crash.

On the other hand, I’m fairly certain, that empty batteries and full ones weigh the same.

This would mean, that the plane aerodynamics and structure,  would be designed to be optimal in the various phases of flight.

  • Taxiing out to the runway.
  • Taking off.
  • The climb to the cruising altitude.
  • The cruise
  • The descent to the destination airport.
  • The landing
  • Taxiing in to the terminal or stand.

In the climb, cruise and descent  phases power would be set and the trim adjusted, by the autopilot to attain the right speed and rate of climb or descent.

Aerodynamics

As the weight of the aircraft would be the same in all three phases and would need more or less the same lift, with clever aerodynamics, I think we will see a very simple wing. In fact, probably more like that of a sailplane than an airliner.

Wikipedia says this about the design.

The aircraft is to run on batteries and handle flights of under 300 miles. It will feature high aspect-ratio wings for energy efficient flight, distributed electric propulsion and swappable battery packs with advanced cell chemistry.

Note that sailplanes have high aspect ratio wings.

Compared to say a small jet airliner like an Airbus A318, I suspect that the wings will be longer, but possibly simpler.

The Wright Electric Jet will probably have various aerodynamic aids, like flaps and winglets. In fact the picture on Wikipedia shows the latter, which reduce drag.

A Simple Flight Profile

The fastest way to fly between A and B is probably to take off and climb as fast as possible to the optimum cruising altitude, where an optimum cruise is maintained, until the time comes to descend into the destination airport. Much of the descent would be straight in to the runway.

I have flown in an easyJet Airbus 320 from Schipol to Southend in much this manner and the plane arrived ahead of schedule.

I suspect that easyJet like to fly like this, as it saves fuel, but Air Traffic Control probably doesn’t allow it that often.

But simple efficient profiles like this would be ideal for electric aircraft.

If as I suspect their aerodynamics would allow a better glide ratio than a jet powered airliner. So to get a longer range, an electric aircraft might do a long approach.

A Low Noise Aircraft

As I said earlier, Wright are talking about fifty percent less noise.

This could be a game-changer for a smaller airport like Luton or Southend, where the approach can be over residential areas.

Especially for Southend, where planes from the East could do a long descent over the sea and come straight in on Runway 23.

Could Southend become London’s short-haul airport for electric aircraft?

  • easyJet and Ryanair are already there.
  • There’s plenty of wind power in the area
  • It has a good rail connection to London and could be served by Crossrail.

Essex is a county that likes to be different.

Airbus

The original article also mentions Airbus.

Airbus has the skills to design the required light and strong airframe, the aerodynamic knowledge.and a large support network.

They also have a lot to lose, if someone else takes away, the smaller part of their masrket.

Ignore Airbus at your peril.

Conclusion

The more I think about it, the more that I think a 120 passenger electric airliner with a range of 540 km, could be a very handy plane.

 

 

December 10, 2019 Posted by | Transport | , , , , , | 2 Comments