Efterbränning

Efterbränning is a Swedish term that literally translates to "afterburning." In its most common technical context, it refers to the process of adding fuel to the exhaust stream of a jet engine to increase thrust. This is typically achieved by injecting fuel into the hot exhaust gases after they have passed through the turbine section of the engine. The added fuel ignites in the presence of the remaining oxygen and heat, creating a secondary combustion event that significantly boosts the engine's power output.

Efterbränning is primarily used in aircraft, particularly fighter jets and high-performance military planes, where maximum acceleration and speed are critical. Engaging the efterbränning is usually indicated by a distinct change in engine sound and a visible plume of flame from the exhaust nozzles. This process is highly fuel-intensive and is therefore used for short durations, such as during takeoff, combat maneuvers, or to break the sound barrier.

The concept of efterbränning was developed during World War II, with early implementations in aircraft like the German Messerschmitt Me 262. Modern jet engines often incorporate sophisticated efterbränning systems that can be controlled to varying degrees, allowing pilots to optimize performance for different flight conditions. While effective for thrust augmentation, the increased fuel consumption and higher temperatures associated with efterbränning place significant demands on the engine's materials and structure.