Abstract :
In aircraft engines, bypass flow is very influential on thrust and specific fuel
consumption because it is very helpful for the engine to achieve efficient output, it
is when an aircraft is operating that is flying at cruising altitude, the air
temperature is very low. So that it is very difficult to do combustion. Therefore, an
increase or decrease in bypass ratio will affect aircraft engine performance. This
research was conducted to find out how the bypass ratio of the engine performance
by CFM 56-5A1 engine in cruising conditions.
The method used in this research is parametric cycle analysis of real engine
using Excel software. After that, the researcher analyzed the engine performance
that has been influenced by variations in the value of the bypass ratio to find out
how the performance generated from the CFM56-5A1 engine.
The value of engine performance is known to decrease and increase with
increasing and decreasing variation of the value of the parameter bypass ratio. So
that if the value of these parameters is greater, the fuel consumption when the
aircraft operates will be less and the thrust will decrease. In addition to change the
value of the output due to the influence of the bypass value, variations in altitude
are also very influential where the higher the aircraft, the resulting output value
will be smaller.