What is the Difference Between Turbojet and Turbofan?
2 Answers
Below are the differences between turbojet and turbofan engines: 1. Different power sources; Turbofan engine: Power comes from the fan and gas expansion work; Turbojet engine: Power source is gas expansion work; 2. Different structural components; Turbojet engine: Compressor + combustion chamber + turbine. Turbofan engine: Fan + bypass duct + compressor + combustion chamber + turbine. Here is some basic knowledge about turbojet engines: The shaft and fan in a turbojet are used to compress air. The compressed air is mixed with fuel in the combustion chamber and burned, then the expanded high-temperature and high-pressure air is ejected from the rear to provide jet thrust. As it passes through the turbine, it causes the turbine to rotate. The turbine is connected to the compressor fan via the same shaft, providing the power for air compression, thus completing the cycle.
I've been repairing aircraft for over a decade. The main difference between turbojet and turbofan engines lies in their intake and exhaust structures. Turbojet engines are older designs where all incoming air is compressed and combusted in the core before being expelled at high velocity through the exhaust nozzle, generating thrust solely from this hot gas stream. These engines perform well at high altitudes and speeds, but have terrifying fuel consumption and deafening noise levels. Turbofans are much smarter - they add a large fan at the front that splits incoming air into two paths: one goes through the core for combustion, while the other bypasses through the outer duct. This bypass airflow is cooler and quieter, contributing about 70% of total thrust, making turbofans more fuel-efficient and environmentally friendly - which is why modern airliners all use them. However, turbojets haven't been phased out completely, as fighter jets still rely on them when maximum speed performance is required.
