Turbofan engines were first named as bypass turbojets by Rolls-Royce. Boeing sometimes refers to them as fanjets [1]. Turbofan engines are the most reliable engines ever developed. Fundamentally, turbofan engines are fuel efficient and quiet, turbine-based engines. They feature continuous combustion and smooth rotation, unlike the internal combustion engine of automotives. The gas generator of a single-spool turbofan has three sections:

Fan unit and compressor section

Combustion chamber

Turbine section

The fan pressurizes air and feeds it aft. Most of this air goes around the engine core and is next ejected through a nozzle called a fan (or cold) nozzle. The rest goes through the engine core, where it is further compressed in a compressor and next then it mixes with the fuel and ignites. The hot expanding combustion efflux passes through the turbine section, spinning the turbine as it exits the engine.