Topic Author
Posts: 25
Joined: Sun Dec 18, 2005 12:17 am

How Does Work The Water Injection System?

Fri Aug 18, 2000 8:11 pm


I ever heard about the water injection system to increase the engines power in take off (such as in the Boeing B52 Stratofortress), but never knew hod does it work...

Anyone can explain it to me?
Posts: 196
Joined: Fri Jul 07, 2000 12:28 am

RE: How Does Work The Water Injection System?

Fri Aug 18, 2000 9:38 pm

"The injection of water into the gas path causes heat transfer. When the fluid evaporates, heat in the air will be transferred into the fluid droplets, cooling the air and making the gas flow more dense. Water injection in a gas turbine engine is then a means of augmenting engine thrust. Augmentation can be thought of as occurring in two ways. First, addition of water to air in the compressor increases compression and mass flow. second, water cools the combustion gases which allows additional fuel to be used without exceeding maximum temperature limits during takeoff. Increases in these three engine parameters results in a thrust increase in the range of 10 to 15 per cent." - taken from Aircraft Gas Turbine Powerplants Handbook.
Posts: 1066
Joined: Fri Mar 16, 2007 1:29 pm

RE: How Does The Water Injection System Work?

Fri Aug 18, 2000 10:25 pm

Sometimes referred to as "Water-Meth" (Methanol) or "Wet Take-Off Power". The methanol is included as an inert agent to prevent the water from freezing, either in the tank, or during the heat transfer referred to above.

A few years ago in northern Manitoba, Canada, an HS-748 was getting ready to depart a small strip. Normal procedure is to arm the water-meth injection prior to throttle up. In this case though, the arming wasn't done until late in the takeoff roll or just after airborne (I can't remember the specific details). Unfortunately, when asked to fuel the airplane earlier, the new fueler mistook the water-meth tank for a fuel tank.

When the kerosene entered the compressor section of both engines, one flamed out, the other exploded in the exhaust section. The plane was deadsticked into a dry river bed with no serious casualties.

Best Regards,

Posts: 6605
Joined: Tue Mar 21, 2000 6:25 am

RE: How Does The Water Injection System Work?

Fri Aug 18, 2000 10:42 pm

Also early 747 clasic airliners had the ability to use water injection. It was only used occationally under hot&high conditions, or at MTOW on marginally short runways. I don't think it is used any more on commercial planes. It gives a terrible smoke.
Also piston engines have used water injection. Especially during WW2, but also later carrier fighters etc.
We are not talking about a few bottles of water. A B-52G could carry 10,000 lbs of water for take-off. It would last only one and a half minute, so the party ended at about 200 feet altitude.
Best regards, Preben Norholm
Always keep your number of landings equal to your number of take-offs
Topic Author
Posts: 25
Joined: Sun Dec 18, 2005 12:17 am

RE: How Does Work The Water Injection System?

Mon Aug 21, 2000 7:36 pm

thanks for the replies  


Who is online

Users browsing this forum: Yahoo [Bot] and 26 guests

Popular Searches On

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos