What is the function of afterburners in turbine engines?

The function of afterburners in turbine engines is to increase thrust by injecting additional fuel into the exhaust. Afterburners are designed to enhance the performance of the engine during high-speed flight. When the exhaust gases leave the turbine, the afterburner injects additional fuel into the hot exhaust stream, which ignites and burns, resulting in a significant increase in temperature and volume of the exhaust gases. This expanded exhaust then produces extra thrust as it exits the engine, allowing for greater acceleration and improved performance in supersonic flight or during takeoff.

The other options do not accurately reflect the primary purpose of afterburners. While noise reduction, fuel efficiency, and cooling might be considerations in an engine's design, they are not the main roles served by afterburners. Instead, their primary purpose is thrust augmentation for enhanced performance in specific flight regimes.