Reaction Engines SABRE engine (Skylon Spaceplane)

[Dagger]

It's just a tubular heat exchanger.

Tubular heat exchangers are the most common heat exchangers in the world, already for many decades. They are available in various sizes and shapes from many heat exchanger companies.

..........................................................................

Tubular heat exchangers with small diameters are beeing used quite succsessfully in racecars, millitary vehicle and some aircraft applications:

Mezzo Microtube Heat Exchangers - Mezzo Technologies

Explore Mezzo Technologies' expertise in engineering custom microtube heat exchangers for extreme performance. Our accountable, technically advanced team pioneers innovation in thermal management, delivering lightweight, aerodynamic solutions for diverse industries.

www.mezzotech.com

..................................................................

That was exactly my point: tubular heat exchangers with small diameter tubes are nothing new or special.

..............................................

.............................................

And finally no, Reaction Engines limited was never established to develop Skylon, there’s a clue in their name which should be very obvious.

A couple of years ago REL changed their logo into a cross section of the precooler:



There's a clue in this new logo which should be very obvious: they are a heat exchanger company.
In the past REL definitely talked a lot about Skylon but since the dreamers retired it is hardly mentioned anymore, and if it is it's about flying to Sidney in four hours instead of flying into space. Hence they don't talk about cooling air to -150 oC anymore because they know very well that the precooler would be completely iced up in no time. They can fake a short test on the ground but not in an actual flying and accelerating plane.

After changing their logo it's now time they also change their name. I suggest 'Radiator Exchangers' which better reflects REL's actual capabilities.

Yet more news from REL.

Project Fresson Update - Phase 1 Underway | Reaction Engines - Making Beyond Possible

Reaction Engines | Pioneering space access and sustainable technologies to elevate life on Earth.

reactionengines.co.uk

Reaction Engines is delighted to provide an update on the progress being made on the Cranfield Aerospace Solutions (CAeS) Project Fresson.

.........................................

Reaction Engines announced that it joined the Project Fresson consortium led by CAeS in October 2021, with the aim to apply its revolutionary thermal management technology developed as part of the SABRE programme, to act as a key enabler for hydrogen fuel cell applications.

................................

Reaction Engines’ heat exchanger technology has been demonstrated as a key enabler for a lightweight and low drag solution. ...............................

Breaking News: REL has sold another radiator, assuming Project Fresson will actually go ahead. The REL financiers will be overjoyed.
Since Mark Thomas is CEO the REL propaganda has changed from laughable into absurdly bombastic. Everything they do is at least "advanced", but more often "innovative", "revolutionary", "ground-breaking", "world-leading", "phenominal".
Calling a rather simple tubular heat exchanger a "revolutionary thermal management technology" is already absurd but now they even call themselves a "key enabler", as if the whole project could not exist without them. What arrogance. For this project their radiator is no more a "key enabler" than the landing gear tyres or the pilot seat.

 

[F119Doctor]

It's just a tubular heat exchanger.

Tubular heat exchangers are the most common heat exchangers in the world, already for many decades. They are available in various sizes and shapes from many heat exchanger companies.

..........................................................................

Tubular heat exchangers with small diameters are beeing used quite succsessfully in racecars, millitary vehicle and some aircraft applications:

Mezzo Microtube Heat Exchangers - Mezzo Technologies

Explore Mezzo Technologies' expertise in engineering custom microtube heat exchangers for extreme performance. Our accountable, technically advanced team pioneers innovation in thermal management, delivering lightweight, aerodynamic solutions for diverse industries.

www.mezzotech.com

..................................................................

That was exactly my point: tubular heat exchangers with small diameter tubes are nothing new or special.

..............................................

.............................................

And finally no, Reaction Engines limited was never established to develop Skylon, there’s a clue in their name which should be very obvious.

A couple of years ago REL changed their logo into a cross section of the precooler:

View attachment 681545

There's a clue in this new logo which should be very obvious: they are a heat exchanger company.
In the past REL definitely talked a lot about Skylon but since the dreamers retired it is hardly mentioned anymore, and if it is it's about flying to Sidney in four hours instead of flying into space. Hence they don't talk about cooling air to -150 oC anymore because they know very well that the precooler would be completely iced up in no time. They can fake a short test on the ground but not in an actual flying and accelerating plane.

After changing their logo it's now time they also change their name. I suggest 'Radiator Exchangers' which better reflects REL's actual capabilities.

Yet more news from REL.

Project Fresson Update - Phase 1 Underway | Reaction Engines - Making Beyond Possible

Reaction Engines | Pioneering space access and sustainable technologies to elevate life on Earth.

reactionengines.co.uk

Reaction Engines is delighted to provide an update on the progress being made on the Cranfield Aerospace Solutions (CAeS) Project Fresson.

.........................................

Reaction Engines announced that it joined the Project Fresson consortium led by CAeS in October 2021, with the aim to apply its revolutionary thermal management technology developed as part of the SABRE programme, to act as a key enabler for hydrogen fuel cell applications.

................................

Reaction Engines’ heat exchanger technology has been demonstrated as a key enabler for a lightweight and low drag solution. ...............................

Breaking News: REL has sold another radiator, assuming Project Fresson will actually go ahead. The REL financiers will be overjoyed.
Since Mark Thomas is CEO the REL propaganda has changed from laughable into absurdly bombastic. Everything they do is at least "advanced", but more often "innovative", "revolutionary", "ground-breaking", "world-leading", "phenominal".
Calling a rather simple tubular heat exchanger a "revolutionary thermal management technology" is already absurd but now they even call themselves a "key enabler", as if the whole project could not exist without them. What arrogance. For this project their radiator is no more a "key enabler" than the landing gear tyres or the pilot seat.

Looks a lot like the P&W Project 304 hydrogen engine heat exchanger from the late 1950s. Completely different engine cycle, but still huge heat transfer: https://history.nasa.gov/SP-4404/ch8-9.htm

 

[Dagger]

Looks a lot like the P&W Project 304 hydrogen engine heat exchanger from the late 1950s. Completely different engine cycle, but still huge heat transfer: https://history.nasa.gov/SP-4404/ch8-9.htm

View attachment 681561

Just like the shape of Skylon looks a lot like Suntan.
Originality is not REL's strongest point.
Smoke, mirrors and fanfare are their specialty.

 

[steelpillow]

Seems that SABRE is rattling a few cages elsewhere. China is hot (or should that be precooled?) on its trail:

https://forum.nasaspaceflight.com/index.php?PHPSESSID=rekp8p59rej25ltjplb689l1cq&action=dlattach;topic=45914.0;attach=2095990;sess=0

 

[overscan (PaulMM)]

Brochure:

https://reactionengines.co.uk/wp-content/uploads/2022/06/Reaction-Engines-Company-Brochure_2022.pdf

 

[steelpillow]

Interesting to see the emphasis on thermal management as a big thing in its own right. Maybe this is why somebody is willing to bet on fuel cells for long-distance electric vehicles and build a fuel cell gigafactory in the UK? (can't remember where I read that).

 

[martinbayer]

Seems that SABRE is rattling a few cages elsewhere. China is hot (or should that be precooled?) on its trail:

https://forum.nasaspaceflight.com/index.php?PHPSESSID=rekp8p59rej25ltjplb689l1cq&action=dlattach;topic=45914.0;attach=2095990;sess=0

I feel more and more like the last original idea to come out of China was movable type printing. These days they seem to be pure copycats.

 

[Flyaway]

Reaction engines to go public with IPO

https://www.cityam.com/bae-backed-spacecraft-designer-reaction-engines-prepares-for-ipo/

Sky covering it too
https://news.sky.com/story/rolls-ro...ts-flight-path-to-1bn-public-listing-12680679

 

[Dagger]

Reaction engines to go public with IPO

https://www.cityam.com/bae-backed-spacecraft-designer-reaction-engines-prepares-for-ipo/

Sky covering it too
https://news.sky.com/story/rolls-ro...ts-flight-path-to-1bn-public-listing-12680679

In other words: the original stakeholders (BAe, RR, Boeing, UKSA, ESA) don't want to put any more money into this radiator company.
Soon after the IPO, when the share price usually peaks, they will dump their shares on the clueless retail investors.

 

[red admiral]

Reaction engines to go public with IPO

https://www.cityam.com/bae-backed-spacecraft-designer-reaction-engines-prepares-for-ipo/

Sky covering it too
https://news.sky.com/story/rolls-ro...ts-flight-path-to-1bn-public-listing-12680679

I wonder what revenue stream REL will promise that will get this level of investment?

 

[Flyaway]

Another spin-off of the technology.

https://twitter.com/x/status/1564890064534093824

View: https://twitter.com/ReactionEngines/status/1564890064534093824

 

[Flyaway]

Presser:

LAUNCH OF SUNBORNE SYSTEMS TO DELIVER WORLD-LEADING DECARBONISATION TECHNOLOGY​

• Decarbonisation technology Company Sunborne Systems set up by Reaction Engines, Kiko Ventures and the UK-Government-funded Science and Technology Facilities Council (STFC)
• Appointment of Dr. Peter Collins as Executive Chair of Sunborne Systems, bringing important entrepreneurial expertise
• Sunborne Systems combines world-leading technical expertise from Reaction Engines and STFC and venture building expertise from Kiko Ventures to develop decarbonisation technology solutions for hard-to-abate sectors

Today it has been announced that the decarbonisation technology Company set up by Reaction Engines, Kiko Ventures and the UK Government funded Science and Technology Facilities Council (STFC) is to be named Sunborne Systems.
Sunborne Systems will combine Reaction Engines’ heat exchanger technology with STFC’s leading ammonia catalyst expertise, and venture building expertise from Kiko Ventures (IP Group’s cleantech investment platform), to design and bring to market lightweight and compact cracking reactors for green ammonia, providing power and propulsion solutions for use in hard-to-decarbonise sectors such as aviation, marine shipping, and power generation.
It has also been announced that Dr. Peter Collins has been appointed as Sunborne Systems’ Executive Chair. Peter will lead the commercialisation of Sunborne Systems’ innovative technology, drawing on his experience in developing and scaling technology-differentiated businesses in the energy, water and other process industries.
Commenting, Peter said: “I am delighted to be joining Sunborne Systems as Executive Chair. Sunborne is strongly positioned to be a market leader in decarbonisation solutions. The Company’s innovative ammonia-cracking technology, backed by expertise from Reaction Engines, STFC and Kiko Ventures, has significant market potential and I look forward to working with this team to establish Sunborne Systems as the key enabler of ammonia-powered transport and power generation.”
Professor Bill David FRS and James Barth, Sunborne co-founders, said: “This is an exciting step forward for Sunborne Systems. Peter’s leadership will accelerate the commercialisation of our joint venture which is set to become a true enabler of ammonia for decarbonisation.”
Dr Liz Kirby, Director of Innovation at STFC, and Richard Varvill, CTO at Reaction Engines, said: “It is fantastic that Peter is joining Sunborne, bringing his wealth of experience in commercialising innovative technology, as we build the business to realise the potential unlocked by technology originating from STFC and Reaction Engines.”
Dr Robert Trezona, Founding Partner of Kiko Ventures said: “Peter’s appointment comes at an exciting time for Sunborne Systems, reinforcing our drive to fully realise the potential of Sunborne’s world-leading technology.”

Press Release - Launch of Sunborne Systems

The fuel revolution is here. Today it has been announced that the decarbonisation technology Company is to be named Sunborne Systems.

sunbornesystems.com

 

[martinbayer]

Grasping for straws now?

 

[Flyaway]

Grasping for straws now?

What a bizarre statement.

 

[martinbayer]

Grasping for straws now?

What a bizarre statement.

Perhaps it's just me, being an old school aerospace engineer, but changing prime objectives from enabling a revolutionary RLV to sucking CO2 out of the atmosphere (both noble endeavors, no doubt), seems like quite a leap. Sour grapes, anyone?

 

[red admiral]

Its a very different company now than even 10 years ago. This sort of exploitation route for their technology might actually generate some revenue in time.

 

[FighterJock]

Its a very different company now than even 10 years ago. This sort of exploitation route for their technology might actually generate some revenue in time.

We might even see some actual engine hardware being built after all this time.

 

[martinbayer]

Its a very different company now than even 10 years ago. This sort of exploitation route for their technology might actually generate some revenue in time.

But it won't really directly serve the original intent and purpose. If generating revenue is now the prime objective/directive, they might as well hawk NFTs or Crypto currency.

 

[martinbayer]

Its a very different company now than even 10 years ago. This sort of exploitation route for their technology might actually generate some revenue in time.

We might even see some actual engine hardware being built after all this time.

Not holding my breath on this one. The market for airborne hypersonic decarboinisation devices appears somewhat limited.

 

[Zoo Tycoon]

sucking CO2 out of the atmosphere (both noble endeavors, no doubt), seems like quite a leap. Sour grapes, anyone?

No CO2 sucking going on here;- making use of Hydrogen and Nitrogen in very clever way.

 

[steelpillow]

"Green ammonia"? I don't like the smell of that. Out here in the sticks, red biodiesel has many advantages.

[Insert better joke than I can come up with about oxidation and oxymorons]

Presumably the heat exchanger is a necessary step in the greenwashing process.

"Cracking ammonia, Grommet. Where did you get it? Wensleydale?"

Perhaps I should add, I am not against this in principle - it has been under development for some time and I am sure the technology works. But I am doubtful about the claimed wonder-world; ammonia is nasty stuff and costs money to keep under safe control, as we move to underground LED hydroponics and AI-controlled greenhouses we will consume more ammonia in the fertilizer feedstocks and there will be less available to crack. Etc. etc. And what benefit does the RE heat exchanger have for industrial processing, over one that is four times the size but only a twentieth the cost?

 

[red admiral]

This ammonia thing is about generating liquid hydrogen for fuel cells or to burn. REL is betting that producing the LH2 from renewables power to liquid it should then be combined with nitrogen to make ammonia as this has some storage and transportation advantages over LH2. But still obvious issues. REL's spinoff tech here is to be able to rapudly crack the ammonia to liberate the H2 for use in fuel cells or simply burn.

We'll see. The LH2 lobby seems to be more vocal / well funded.

 

[Dagger]

............................................ REL's spinoff tech here is to be able to rapidly crack the ammonia to liberate the H2 for use in fuel cells or simply burn.
...........................................

REL's spinoff tech here is only providing a heat exchanger.
The cracking technology comes from the other companies mentioned in the press release:

Presser:

............................
Sunborne Systems will combine Reaction Engines’ heat exchanger technology with STFC’s leading ammonia catalyst expertise, and venture building expertise from Kiko Ventures (IP Group’s cleantech investment platform), to design and bring to market lightweight and compact cracking reactors for green ammonia

 

[steelpillow]

We might even see some actual engine hardware being built after all this time.

Not holding my breath on this one. The market for airborne hypersonic decarboinisation devices appears somewhat limited.

How about realtime cracking of ammonia to provide a stream of hydrogen fuel to SABRE? You'd certainly need RE-class heat exchangers for that!
Benefits would be easier liquefaction and drastically reduced flammability of the onboard fuel, downsides would be a lot of dead-weight nitrogen in the tank and mild toxicity of any escaping fumes/spillage.
They could also mix the nitrogen back into the rocket efflux, to increase mass flow and hence thermodynamic efficiency when in non-airbreathing spaceflight mode.
But no, I'm still not rushing out to buy shares in ammonia-filled aeroplanes.

 

[Archibald]

We might even see some actual engine hardware being built after all this time.

Not holding my breath on this one. The market for airborne hypersonic decarboinisation devices appears somewhat limited.

How about realtime cracking of ammonia to provide a stream of hydrogen fuel to SABRE? You'd certainly need RE-class heat exchangers for that!
Benefits would be easier liquefaction and drastically reduced flammability of the onboard fuel, downsides would be a lot of dead-weight nitrogen in the tank and mild toxicity of any escaping fumes/spillage.
They could also mix the nitrogen back into the rocket efflux, to increase mass flow and hence thermodynamic efficiency when in non-airbreathing spaceflight mode.
But no, I'm still not rushing out to buy shares in ammonia-filled aeroplanes.

Big problem for airliners: ammonia is easy to store but sucks as a low energy fuel. And hydrogen is the exact opposite: pure energy but dismal storage, a full and entire and complete PITA: wrong density, wrong temperature, wrong explosivity index. All wrong, the damn thing.

Now what we need would be some kind of magical gizmo that could instantly turn ammonia (in the tanks) into hydrogen (in the engines).

Is that even remotely feasible ?

Removing the nitrogen (to get pure hydrogen) and drastically lowering the temperature (to get that hydrogen into liquid form) obviously are no walk in the park...
Can turbofans runs on gaseous hydrogen, or is liquid state mandatory ? I suppose the risk of KABOOM ain't small either.

 

[steelpillow]

How about realtime cracking of ammonia to provide a stream of hydrogen fuel to SABRE? You'd certainly need RE-class heat exchangers for that!
Benefits would be easier liquefaction and drastically reduced flammability of the onboard fuel, downsides would be a lot of dead-weight nitrogen in the tank and mild toxicity of any escaping fumes/spillage.
They could also mix the nitrogen back into the rocket efflux, to increase mass flow and hence thermodynamic efficiency when in non-airbreathing spaceflight mode.
But no, I'm still not rushing out to buy shares in ammonia-filled aeroplanes.

Big problem with ammonia airliners: ammonia is easy to store but sucks as a low energy fuel. And hydrogen is the exact opposite: pure energy, but dismal storage, a complete PITA.

Now what we need would be some kind of magical gizmo that could instantly turn ammonia (in the tanks) into hydrogen (in the engines).

Is that even remotely feasible ? Removing the nitrogen (to get pure hydrogen) and lowering the temperature (to get that hydrogen into liquid form) obviously are not small feats...

I am beginning to wonder if this is how RE got involved in the "green" ammonia-cracking project. If there is one thing they know how to do, it is to drive fluid-dynamic processes at speed.

 

[Archibald]

Fact is, if REL comes with an ammonia-to-hydrogen "in flight processing system" they will be heroes. Provided the said system can be a viable alternative to the classic kerosene-fueled airliner. Which, once again, won't be easy at all.

There is no easy path for aviation to go out of kerosene. Ships and freight trains and trucks and bus can go ammonia; cars can go electric or methanol. But aviation needs a lot of energy. Flight ain't easy.

 

[F119Doctor]

We might even see some actual engine hardware being built after all this time.

Not holding my breath on this one. The market for airborne hypersonic decarboinisation devices appears somewhat limited.

How about realtime cracking of ammonia to provide a stream of hydrogen fuel to SABRE? You'd certainly need RE-class heat exchangers for that!
Benefits would be easier liquefaction and drastically reduced flammability of the onboard fuel, downsides would be a lot of dead-weight nitrogen in the tank and mild toxicity of any escaping fumes/spillage.
They could also mix the nitrogen back into the rocket efflux, to increase mass flow and hence thermodynamic efficiency when in non-airbreathing spaceflight mode.
But no, I'm still not rushing out to buy shares in ammonia-filled aeroplanes.

Big problem for airliners: ammonia is easy to store but sucks as a low energy fuel. And hydrogen is the exact opposite: pure energy but dismal storage, a full and entire and complete PITA: wrong density, wrong temperature, wrong explosivity index. All wrong, the damn thing.

Now what we need would be some kind of magical gizmo that could instantly turn ammonia (in the tanks) into hydrogen (in the engines).

Is that even remotely feasible ?

Removing the nitrogen (to get pure hydrogen) and drastically lowering the temperature (to get that hydrogen into liquid form) obviously are no walk in the park...
Can turbofans runs on gaseous hydrogen, or is liquid state mandatory ? I suppose the risk of KABOOM ain't small either.

Yes, turbofan engines can run on gaseous hydrogen, with properly designed fuel controls and combustor fuel nozzles. Hydrogen burns very quickly and likely would be a superior fuel compared to kerosene, if that were the only consideration. In fact, liquid hydrogen has tremendous capability to drive turbines just with the phase change to gas as it absorbs vaporization heat - see Pratt & Whitney Project 304.

Of course the real problem with hydrogen is storage. Even in a supercooled liquid start, the volume is large. On the RP-1/LOX Saturn V, the LOX tanks are twice the size of the kerosene tanks. But the LH2 fuel tanks on the space shuttle are twice the size of the LOX tanks. You can make an airliner with LH2 fuel, but there may not be enough space for the passengers.

Whether you can store enough H2 in Ammonia form and turn it into a usable form fast and efficient enough to make it worthwhile is the question.

 

[Nicknick]

For combustion processes, a partially cracking is feasable, with the remaining Ammonia beeing burned just like the Hydrogene. For PEM fuel cells, you have to use a very clean hydrogene gas an you need to a additional step for the gas cleaning. For this reason, Ammonia is more feasable for combustion engines and turbines than for fuel cells.

Ammonia or N2O emissions might be an issue especially for turbines, since exhaust after treatment is not feable with the high mass flow.

 

[red admiral]

For combustion processes, a partially cracking is feasable, with the remaining Ammonia beeing burned just like the Hydrogene.

This is how I've seen REL explain it. Convert some Ammonia into LH2, easily ignite the LH2 and then add Ammonia which decomposes and then burns the H2.

But Ammonia is not without its own storage problems etc.

 

[Nicknick]

It doesnt make sense at all to produce liquid hydrogene, it needs terrible lot of energy (and machinery) to produce and burning liquid hydrogene will release less enegry than burning gaseous Hydrogene because you have to overcome the vaporisation heat.

For cracking ammia you just need some exhaust heat (or use it for cooling the turbine blades) and than you can burn a mixture of Ammonia and Hydrogene.

 

[F119Doctor]

It doesnt make sense at all to produce liquid hydrogene, it needs terrible lot of energy (and machinery) to produce and burning liquid hydrogene will release less enegry than burning gaseous Hydrogene because you have to overcome the vaporisation heat.

For cracking ammia you just need some exhaust heat (or use it for cooling the turbine blades) and than you can burn a mixture of Ammonia and Hydrogene.

The P&W 304 engine recycled exhaust heat to heat the LH2 with resulting vaporization expansion through a turbine powerful enough to drive the inlet fan. The P&W RL10 rocket engine cools the combustion chamber and nozzle with LH2 with vaporization expansion driving the LH2 and O2 pumps. And at least in their original concept, RE was using the LH2 vaporization to precool high supersonic inlet air down to temperatures where a conventional jet engine could operate effectively. LH2 can be an effective fuel with its cryogenic temperatures and vaporization being utilized to recycle waste heat and cool critical parts of the engine.

Looking at ammonia specific gravity and heat content says it takes up less space than LH2, but still will require significantly larger tank volume than kerosene.

 

[Nicknick]

It is something completely different when you have liquid Hydrogene on board instead of liquifiying it after producing it out on Amonia (dosen"t make any sense). As we can see from your exampels, non of them will burn liquid Hydrogne directly because it would be a waste of energy, so the vaporisation heat is used for cooling.

About the tank size, Ammonia has a volumetric energy density of 3,536 kwh/L and liquid Hydrogen 2,4 kwh/L. In reality, the tank size not only depends on the volumetric energy density but also on the amount of isolation which is around. For this reason, the Ammonia tanks are much smaller than the Hydrogen tanks.

Of course, Amonia is not suited for the extrem longhaul traffic, but this is just a fraction of total air traffic.

 

[Zoo Tycoon]

Looking at ammonia specific gravity and heat content says it takes up less space than LH2, but still will require significantly larger tank volume than kerosene.

Your assuming Ammonia will use the same Brayton cycle as a kerosene gas turbine, maybe not.

Ammonia’s latent heat of vaporisation, a whopping 1370Kj/Kg, indeed the highest known.

It’s the useable energy fraction that’s key not the simple energy density.

 

[Nicknick]

Ammonia is easier usable for combustion engines than for turbines, because it can be evaporated by the cooling heat and cracked by the exhaust heat. So higher the Hydrogen content after cracking, so more exhaust heat will be converted to usefull chemical energy, but to much Hydrogen will cause problems with flame back, pre-ignition and knocking, so that there is no need for a very high cracking rate.

As said, Ammonia and the cracking reaction could be used for blade cooling in a turbine, this could lead to an higher efficiency, but you need quite a lot of modifications over the standart design.

 

[Zoo Tycoon]

Not blade cooling.

As per the project below;- Use Ammonia’s unique thermo fluid properties to Improve the thermal cycle efficiency to close to double that of Kerosene. In simple terms the useable energy fraction of both Ammonia and kerosene are approx the same.

QED - a long range aircraft zero carbon fuel.

As for low NOX, remember the NOX reducing additive “Add Blue” used in diesel engines utilises Ammonia as it’s active ingredient, yes ammonia scrubs out the NOX . Dumb burning produces lots but clever burning has been demonstrated to give very low levels.

https://arpa-e.energy.gov/sites/default/files/2021-02/04_Smith_ZAPTurboKickoffJan2021_vIII.pdf

 

[Nicknick]

I think we should merge this topic:

https://www.secretprojects.co.uk/threads/zero-carbon-fuel-pn-calum.37508/#post-486125

The whole Ammonia topic doesnt really fit in here.

BTW: I dont believe, that using Ammonia instead of Kerosene could double the efficiency (40 =>80 % ???)

 

[bobbymike]

Air Force Testing High-Mach Engine Technology

Air Force Testing High-Mach Engine Technology

www.nationaldefensemagazine.org

 

[Archibald]

Ammonia is easier usable for combustion engines than for turbines

Does that mean "piston engines" as in Super Constellation ? the irony, that would be. Should we bring back the Convair XC-99 or Lockheed Constitution ? Except with ammonia ?

 

[GTX]