>RR RB211-524d4 at 4.311:1 (a bit less than it's sisters due to a bigger diameter L.P turbine).<
OK, you got me here
Why does a bigger dia L.P turbine lower the by-pass ratio?
I can understand the need for a bigger dia LP turbine to support a bigger by-pass ratio (need more horsepower and torque to drive a bigger fan) and I can understand a bigger core with the same size fan lowering the bypass ratio.
Please explain what's really going on with the comment above
