jet engine and water intake.

[funkymoped]

im more curious about this that it being a must know thing.

how much water can a jet engine draw in before it stalls ? ive never one read of a jet engine stalling because it goes through a storm of storm cloud. the way a jet engine works it would suck possably tons of water in to the intakes at maximum engine speed/air speed.

anyone ?

[Catso]

No idea about the actual weight/amount, but I'd say quite a lot! Never mind in a storm, I'd imagine a jet going down a wet runway sucks in much more water.
I presume they are tested for such things as you wouldn't want the fire going out as you're hurtling at 200MPH towards the end of the runway!
I believe some jet engines have/had deliberate water injection to temporarily increase the thrust. (It expands to steam)

[Clanad]

Firstly, this video might be educational: http://www.geae.com/education/engines101/popups/mov_wateringestion.html

This is a required test for certification of the engine. The quantity of water used is huge, but I don't have the quantitiy figures at hand.

Secondly, the newer high-by pass ratio turbo fans could actually take even more water since, as the name implies, the large shrouded fan at the front of the engine bypasses a lot of the incoming air and acts as a propeller, giving the engine more efficiency, especially at the lower take-off speeds.
The take-off ingestion of standing water is ameliorated by the design of the nose gear "chined tires". There's a pronounced rubber "rim" near the tread of the tire that flares the water out and away form the intakes of the engines. This, is in addition to deflector vanes attached to various locations on the forward fuselage. One final design feature is the use of continuous ignition selection when in heavy turbulence and rain/precipitation. (Normally, the ignition is turned off).

[Gef]

Nice answer and link Clanad, always wondered about that. However, still not looking forward to long flight to NZ in June.

[Clanad]

I don't envy you gef... I've done multi-crew long hauls before, and they're not a lot of fun... primarily they fit in the category of "Hours and hours of sheer boredom....". But I do envy you're visist to New Zealand!

[funkymoped]

Clanad, that is an amazing piece of video footage.

i guessed an engine could take "tons of water" during take off and in flight, but would never have guessed an engine could run with so much water being forced into it.

[ACB312]

Just following the thread - for Gef. I'm not long back from NZ having spent January in South Island. Flights were with Emirates (from Glasgow via Dubai) with no problems. The on-demand in flight movies/music/news were excellent and removed much of the boredom of long haul.I did the same trip in 2002 using Singapore Airlines and they were excellent. Respond here if you want more details.

[Gef]

Many thanks ACB. I'm flying with Singapore (Glasgow - Heathrow (with BA) - Singapore - Auckland). Any tips most welcome.

Apologies to funky for hijacking your thread.

[ACB312]

For GEF. The Heathrow part of our journey was the worst. Major refurbishment was ongoing and there was little consideration given for passengers in transit. The Singapore staff were excellent and beautiful - sorry to be slightly sexist but the cabin girls just glided about (apparently on castors) and looked after us just fine. They seemed to offer just one drink at a time but if you wanted any more a visit to the galley was always successful. If you are stopping over in Singapore a visit to Sentosa Island is recommended if you have kids to entertain (or yourself) but watch the weather forecast seriously - we got caught in a tropical storm and had trouble getting back to our stopover hotel, but that was bad management on our part. The in-flight on-demand entertaiment is excellent and should while-away the hours.We were a bit disenchanted with Little India in Singapore and would not recommend it unless you were a serious barterer or dealer in gold.

[Catso]

Cool video! That plume of steam (or maybe water) shotting out the back!!!

[Budgie111]

Additional info on casto's comment on water injection,

The injected water vaporises and cools down the air through the intake which in turn increases the density of the mass flow air into the engine. With this increase of mass flow into the engine there can be a increase of fuel to maintain the Stoiciometric Ratio ( 15/1 Air to fuel mix). This is how extra thrust is obtained.