What is the purpose of an engine nacelle?

The primary purpose of an engine nacelle is to reduce aerodynamic drag around the engines. Nacelles are designed to streamline the flow of air around the engine, minimizing turbulence and drag, which enhances the overall efficiency and performance of the aircraft. By carefully shaping the nacelle, designers can ensure that the airflow remains smooth as it passes around the engine, thereby reducing the aerodynamic resistance that the aircraft needs to overcome during flight.

While engine nacelles may have other functions, such as housing the engines and providing structural support, their main aerodynamic role is to improve the aircraft’s performance by reducing drag. This reduction in drag is crucial for enhancing fuel efficiency and maximizing the aircraft's range and speed during flight.