Jet Engine

A jet engine (or gas turbine engine) is a type of internal combustion engine that generates thrust by drawing in air, compressing it, mixing it with fuel, igniting the mixture, and expelling the resulting high-velocity exhaust gases. The fundamental operating principle follows the Brayton cycle: intake, compression, combustion, and exhaust.

Main types of jet engines used in aviation:

• Turbojet: All thrust comes from the exhaust. Efficient at very high speeds (Mach 2+) but noisy and fuel-hungry at subsonic speeds. Used on early jet airliners and some military aircraft
• Turbofan: A large fan at the front bypasses most of the air around the core engine. Modern high-bypass turbofans (bypass ratios of 8:1 to 12:1) are quieter and far more fuel-efficient. Used on virtually all modern airliners
• Turboprop: The turbine drives a propeller through a gearbox. Most efficient at speeds below 400 knots and at lower altitudes. Common on regional aircraft
• Turboshaft: Similar to a turboprop but the output shaft drives a helicopter rotor or other machinery instead of a propeller