The method of propulsion is mainly used to classify airplanes. Every airplane needs propulsion to move in the air. However, the ways used to create this force will be different. Some of them make use of jet engines to make propulsion. These airplanes are known to be jet aircraft and they are the most used airplanes by commercial airlines.
The jet aircraft produce propulsion from a single or more than one jet engine. Most jets feature 2-4 jet engines. They will be situated in even numbers on either side of the aircraft engine. Jets are distinguished from the internal combustion engines they use. They are similar to trucks, cars, and automobiles powered by gas. While operating, these engines burn a combination of fuel and air to produce propulsion. These elements will be forced into the combustion chambers of the engine, which makes the ignite. The gases will be then released from the engine’s back, making the jet propel.
The major components of a jet engine can be divided into two sections – cold sections and hot sections. The components come under these sections. Let’s take a look at these components.
- Air intake or inlet
The inlet will be a duct for all subsonic aircraft, that ensures effortless airflow to the engine even after the air comes to the inlets from different directions apart from straight ways. It happens on the ground from various crosswinds and it will happen in the flight with yaw motions as well as aircraft pitch. To minimize weight and drag, the duct length will be reduced.
- Fan or compressor
Compressors are made from stages. Stationary vanes or stators and rotating blades will be available in each stage. When the air goes through the fan or compressor, the temperature, and pressure increase.
- Bypass ducts
They offer circulation from the fan at lesser losses to the propelling nozzle of the bypass. On the other hand, the flow of the fan can be combined with the exhaust of the turbine before they enter into the sole propelling nozzle.
This is the part that connects the compressor and the turbine. It is responsible for running the major part of the engine’s length. Mostly, there will be 3 concentric shafts.
- Diffuser section
The compressor delivery air will be slowed down by the diffuser to minimize losses in the flow in the combustor.
- Combustion chamber or combustor
After igniting initially, the fuel will be continuously burned when the engine starts.
It is a bladed discs series that plays the role of a windmill to extract energy from different hot gasses that leave the combustor. A part of this energy is used to operate the compressor.
- Reheat or afterburner
It generates extra thrust by igniting the jet pipe’s fuel. Turbine exhaust gas reheating increases the exhaust velocity and entry temperature of the propelling nozzle.
- Nozzle or exhaust
The gases in the turbine exhaust go through the nozzle to generate a jet of high velocity.
- Supersonic nozzle
A supersonic nozzle is used for nozzle pressure ratios of increased nozzle pressures.