In commercial aviation, it seems jet engines grow and bypass ratio increase with newer engines. Here is some examples:
- 1963: bypass ratio: 0.96 (P&W JT8D)
- 1970: bypass ratio: 5.0 (P&W JT9D)
- 1984: bypass ratio: 5.3 (P&W PW4000)
- 1984: bypass ratio: 6.0 (P&W PW2000)
- 2004: bypass ratio: 8.5 (Rolls-Royce Trent900)
- 2007: bypass ratio: 10.8 (Rolls-Royce Trent1000)
- 2015: bypass ratio: 12.0 (P&W PW1124G)
The bypass ratio has been multiplied by nearly 2 in 30 years (1970 -> 2015). I understand the need of really high bypass ratio to decrease fuel consumption while increasing thrust. To have big bypass ratio, the high pressure part of the engine must be small compare to the overall size of the engine.
- What prevent jet engine designer to design smaller high pressure part or bigger jet engines to increase the bypass ratio?
- Is there someone that has made prediction about the increasing bypass ratio in the next decades and written it in a serious article?