Why doesn’t rain disturb jet plane’s turbine the way water droplets would tear apart a steam turbine? Is it the higher pressure of operation for a steam turbine, I WAG?
- Jinx
Why would it? The droplets would just be vaporized and shot out the back with the rest of the hot gasses.
Rain does indeed erode an engine’s airfoils over time. Rain isn’t just water. Each drop forms around a tiny dust particle. Even when the water has passed deeply enough into the engine to vaporize, that solid bit remains and causes damage that accumulates over time. A high-time engine that has seen a lot of rain will look seriously chewed up.
The issue you’re thinking of with steam turbine buckets is mainly thermal - a stream of water hitting something at high temperature can cause shock cooling and local spalling. That can happen with a gas turbine too.
Part of the reason rain (and hail and dust) ingestion in an aircraft engine isn’t all that big a deal is that the big fan up front is a highly effective centrifuge - most solids (and liquids) get flung away from the entrance to the high temp/high pressure core.
Some jet aircraft (the Republic F-105 Thunderchief comes to mind) had water injection to increase thrust on take-off.
Early B-52’s and KC-135’s, too. Some piston aircraft in WW2 had a similar system.
The idea was that the water would limit combustor temperatures and allow more fuel to be poured in, increasing pressure and power output.