Eli5: What happens to the rain that goes into jet engines while in flight?
In: Engineering
It gets boiled and turns into high temperature steam from the high combustion chamber temperature in the jet engine. There are actually some very interesting videos of jet engine manufacturers testing this at the factory by spraying huge amounts of water into a running engine. The fire in the jet engine is too strong to get extinguished by the water. In fact the expanding steam might help generate thrust in the engine. When the steam is exhausted out the back of the jet engine it will cool down in the ambient air and eventually condense back into water droplets.
If it goes through the “fan” part, it just gets blasted out the back. If it goes through the actual fuel-burning-engine part then it gets boiled and may even marginally improve efficiency.
In modern engines with a high bypass ratio most of the water gets centrifugally spun around the core and passes straight through the fan with no effect.. even super heavy rain has no appreciable effect.
The small amount that does make it into the core quickly becomes steam and passes through without any noticeable effect.
After the engine exploded on Qantas flight QF15 fire crews in Singapore tried for a very long time to extinguish the still running number 1 engine with a fire hose but it didn’t work until mechanics were able to manually close a fuel valve (IIRC).
https://images.app.goo.gl/gRCRTodnT8VxTz2bA
Edit: QF32 not 15 🤦♂️ and foam not water. Thx
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