Turbofan Engines: Bypass Ratio Selection Criteria

[vincentryan]

What Basis Bypass Ratio Has Chosen For Turbofan Engine

 

[minger]

Bypass ratios range from very small in some applications to very large in others. What do you mean by basis?

 

[FredGarvin]

It's all dictated by the cycle requirements. There is no quick way to nail it down.

 

[vincentryan]

if you see bypass ratio varies from 0.1:1>br<1:1 for turbojet engine and 5:1>br<11:1 for turbofan engine.
Some turbofan engine has bypass ratio CFM 56 2c1 has 6, and CFM 56-5b3/4 has 5.3 and 5.5 has Ge 90 has 8.4 and ge 90-115b has 9 and various ratio. when your check this the thrust range is also varies with bypass ratio. is bypass ratio chosen by thrust or any other parameter.

 

[mugaliens]

It's chose by flight regime of the engine's intended use. For most commercial applications, high bypass turbofans are more efficient, as the design parameter is simply sustained high sub-mach cruise, with sufficient thrust for one engine-out performance at max gross take-off weight.