The physics behind a jet engine used in combat fighters involves the principles of Newton's laws of motion, thermodynamics, and fluid dynamics. A typical jet engine operates on the principle of jet propulsion, which generates thrust to propel the aircraft forward. Let's explore the key components and processes involved:
Intake: The jet engine begins by drawing in large quantities of air through an intake system. The intake is designed to compress the incoming air and direct it into the engine.
Compressor: The compressed air then enters a series of rotating blades called the compressor. The compressor further compresses the air, increasing its pressure and temperature. The compression process is achieved by the rotational motion of the compressor blades.
Combustion: Once the air is compressed, fuel is injected into the combustion chamber. Ignition occurs, typically through the use of a spark, and the fuel-air mixture combusts. The combustion process releases a significant amount of heat and generates high-pressure gases.
Turbine: The high-pressure gases from combustion flow through a turbine. The turbine consists of a series of blades that extract energy from the hot gases as they pass over them. This energy extraction causes the turbine to rotate.
Exhaust: As the high-pressure gases pass through the turbine, their energy is transferred to the turbine blades, causing them to rotate. This rotational motion is transmitted to the compressor via a shaft, helping to drive the intake and compression stages. The high-velocity exhaust gases exit the engine through a nozzle at the rear, creating a powerful jet of hot gas.
Action and Reaction: According to Newton's third law of motion, for every action, there is an equal and opposite reaction. In the case of a jet engine, the action is the expulsion of high-velocity gases from the exhaust nozzle. As the gases are expelled with significant speed and force, they exert a backward force on the engine, known as thrust. This thrust is what propels the aircraft forward.
The thrust produced by the jet engine is a result of the combined processes of compression, combustion, and the expulsion of high-velocity gases. By continuously repeating these processes, a jet engine can generate a continuous and powerful thrust, allowing the aircraft to move forward.
It's important to note that different types of jet engines, such as turbojet, turbofan, or afterburning engines, may have variations in their specific designs and processes. However, the underlying principle of jet propulsion and the generation of thrust remain consistent.