Interesting GE statement

So I was just reading an interesting statement by GE, on the GE9X engine. They said that they are studying the "right technologies" for the GE9X, which includes water injection. An earlier statement said they had no plans to use water injection in the engine.

Apparently Emirates approached them about the possibility of adding water injection, saying that he understood that the GE9X may not work in desert environments without water injection. The water would be used to provide a cooling stream to the engine to provide more power.

www.flightglobal.com...

reply to post by Zaphod58


Honestly I fail to really understand the benefit of a coolant system VS weight gain in performance, from my understanding the weight gain and extra maintenance involved will be very prohibitive to carry over the long haul.

I'm not an engineer by any means, but did work on military aircraft for years as well as teach the new ones how it works from a mechanics view point.

I can see this on ground engines being a huge benefit however, many jet engines run mobile power stations etc. and are the same models as in the (some) aircraft.

Cheers, and interesting topic.

reply to post by Treespeaker


We used to launch KC-135As and B-52s up through the G with water injection, and it made a big difference in performance. The dry thrust was 11,600 pounds, the wet thrust was 12,400 pounds. We could launch with a higher fuel load with wet thrust, than with dry. Some scary moments when they lost water on take off though.

Don't know huge amounts about jet engines. But in a four stroke engine the cooler you can get the air going into the engine the more power it generally will make? So would using tech such as the reaction engines precooler www.youtube.com... work in a similar way without having to continuously reload with water and risk running out?

reply to post by solidshot


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On a technical note, it's the vaporization/expansion of the water that provides the cooling effect
which make the incoming air DENSER and thus helps the combustion process. Takes advantage
of the 2nd law of thermodynamics...(i.e. Entropy/Equilibrium/Conservation of Energy in a system).

To skirt some fine Early 90's Technical Operations lines, I'm gonna say that one method we used to
cool high performance systems was to use pressurized Methane AND FINELY INJECTED Water Vapor
which creates an initial cooling effect of the RAPIDLY EXPANDING methane and then using a
"special" catalyst create Carbon Monoxide which was used as a LUBRICANT/Secondary coolant
for critical parts in the turbine systems and then recombine the resulting Hydrogen gas
with oxygen to form ANOTHER water cooling cycle on incoming rammed air. Performance gains
were an ASTOUNDING 20%+. The combustion/ignition chamber design we used soon came out on
a very famous Big-3 truck that we see today. It's the specialty fuel and coolant injection designs
that made ALL THE DIFFERENCE in terms of performance gains. Tens of THOUSANDS of total
hours of computational fluid dynamics testing was the KEY ingredient! Think many racks and racks
of Motorola 68030 cpu's running at MUCH LESS than 100 mhz do the work what ONE Windows
AMD Opteron/Firestream cpu/gpu box will do today!

Just to give you a hint or three, we're talking about 205,000 lbs of thrust on a 110,000 lbs craft
over the 170,000 +/- lbs of thrust on straight liquified fuels. And as the craft got lighter, and
and the aerodynamic sheathing sleeker, that initial thrust numbers increase counted BIG TIME
for the up-curved-based final velocity gain!

My colleagues now say that the Beatles song of "Lucy in the Sky With Diamonds"
is a most apt description of just how heady and high those days were in terms
of rocking the aero-performance envelope!

reply to post by StargateSG7


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And as you ponder that ALMOST 2:1 Thrust-to-Weight ratio....I think you can
gather the supreme importance and significance of my above statements
especially since that we're talking about the Years Plus/Minus 1990 here!

reply to post by StargateSG7


I've heard a lot of absurd claims over the years, but what HAVEN'T you claimed to have developed yet?

Zaph, I'm way out of my depth here, but doesn't water also burn above a certain temperature?

There was water injection in some of the early diesels and I don't think air cooling was the main purpose. Again, I have no idea what I'm talking about....as usual.

reply to post by nwtrucker


It can, but the temperatures the water is exposed to in the engine aren't high enough to let that happen. You either add the water to the fuel/air mix, or into the cylinder itself. It cools the mix, and allows more to be added to the cylinder, providing more power.

reply to post by Zaphod58


---

I'm the official observer and i've been around simply because of some lucky coincidences
and friends/relatives in high places. But then again you have to take EVERYTHING I say
with a grain of salt since ...YOU DO KNOW THIS....RAIGHT?..THIS IS ATS!... is there
anything or anyone that's REAL ON HERE? or maybe i'm just yanking the chain of
all you conspiracy opinionists.....or....could be that I am a PAID disinformation
agent.....a simple teenage Troll.....or may I really DO have a super-duper 90nm
photolithography lab in my basement and maybe I really DID design a super-duper
grid-processing system to help design a super-duper secret ultra-transonic aerospace craft
in 1990 which has been operational for over 20 years now! ...or NOT! Maybe that's all bunk!
Oh well! This IS ATS! ---- IS IT REAL or is it MEMOREX?

Keep your eyes open! You're ears piqued! and Your brain on overdrive!
Cuz ya NEVER know what's real or imagined by me!

reply to post by StargateSG7


---

Turbine = Turbo-Pump Fuel Injection + Rammed Air = PDWE
AlO2 + Cellulose Ether + Zirconia = Anti-Corrossive + Heat stable!

Do think that's enough?

CH4 + Air + H2O + Catalyst = CO + H2 + NOx = H2O + don't worry
about the CNx + more Air = 2:1 Thrust-to-Weight = really fast.

68030c at 50 MHZ x racks and racks of em = CFD + FEA = good engine!


...BUT IS IT ALL REAL?

Is the water injected as a mist to the front of the jet engine (before the first compressor blade)?

Is the water chilled pre injection?

reply to post by IamSirDrinksalot


It can be injected directly into the fuel air mix itself, or directly into the cylinder (at least that's how it was done on the -135 and B-52).

It's usually just demineralized water, it doesn't have to be cooled.

The water mist is able to absorb heat as the water evaporates- changes from liquid to gaseous / vapor. The water vapor then transports that heat out of the engine via the exhaust, largely unaffected by the heat of combustion.

Using other media such as methanol, propane or isobutane can enhance the effect. And since those are combustible, they can also add to the power generated by the engine.

A few years ago during a period of high oil prices some of the larger truck engine manufacturers were trying diesel/water mixes in an attempt to improve the fuel economy of their engines (Iirc the process was called emulsification of similar?)

Honda also used to spray water into the exhaust pipes on their 500cc GP bikes at one period in time. They claimed that it gave their engines more mid range torque?

StargateSG7
Just to give you a hint or three, we're talking about 205,000 lbs of thrust on a 110,000 lbs craft
over the 170,000 +/- lbs of thrust on straight liquified fuels. And as the craft got lighter, and
and the aerodynamic sheathing sleeker, that initial thrust numbers increase counted BIG TIME
for the up-curved-based final velocity gain!

My colleagues now say that the Beatles song of "Lucy in the Sky With Diamonds"
is a most apt description of just how heady and high those days were in terms
of rocking the aero-performance envelope!

edit on 2013/9/26 by StargateSG7 because: hint hint!

Hmm, SR-71 empty weight 67,500 lbs, laoded, 152,000.

Early 90's I seem to remember feeling a number of sharp "earthquakes" in So Cal, at one point every Thursday.

68030c, yeah, 1990 or so, Apollo/Sun-3/Stardent/VME board computer era.

www.dow.com...