How it Works

Jet engines operate on the principle of Issac Newton’s Third Law of physics: for every action there is an equal and opposite reaction. All jet engines, also called gas turbines, function by the same principle called thrust. Air is sucked into the engine by some means. It then travels through the compressor which raises the air pressure. The air is compressed by many rotating blades within the compressor. This compressed air enters the combustion chamber where it is sprayed with fuel to create an air-fuel mixture. Combustion occurs with the ignition of an electric spark. Hot burning gases expand and exit into the turbine causing the turbine blades to rotate. At the tail end of the engine, these gases are blasted through the exhaust duct known as the nozzle. The blast causes a great force that thrusts the plane forward at high speeds.

The total thrust is the sum of the two velocities (outlet velocity minus the inlet) times the air flow rates through each section. Engine thrust may be increased through an afterburner section. It is an additional section where fuel is again sprayed on the exhausting gases. At approximately 400 mph, one pound of thrust equals one horsepower. At higher speeds, the ratio increases to a pound of thrust being greater than one horsepower. Similarly, at speeds of less than 400 mph, the ratio decreases.

The advantages of jet engines over piston engines include lighter weight with greater power, simpler construction and maintenance with fewer moving parts, and efficient operation with cheaper fuel.