cx007 wrote:
...found that the high pressure stage of the turbine and compressor of Trent 900 turn in different direction from the rest. How is it possible? I know they have 3 independent shafts, but how can 1 of them turn in another direction? Is it because the direction of the blades of that stage is different?
I don't fly an aircraft with Trent 900s (sadly), but my little RB199s also have the LP and IP turning one way, and HP the other. According to Mr R-R this is
"reduces gyroscopic coupling effects and resonant vibration".
I have a picture of the offending article here, and it sure looks like the HP blades are the other way around. Makes sense I guess. Saying that, I'm sure someone who has built / invented / designed these things will correct me!
Hope that's of some help,
Psy