What is the function of a nacelle in an aircraft?

The correct function of a nacelle in an aircraft is to protect and cover the engine. Nacelles are streamlined enclosures attached to the aircraft's fuselage or wings where engines are mounted. Their design serves multiple purposes: they safeguard the engine from environmental factors such as debris and weather, reduce noise from the engines, and help in aerodynamic efficiency by streamlining the airflow around the engine, minimizing drag.

While nacelles do contribute to the overall aerodynamics of the aircraft, the primary purpose is ensuring the engine is securely housed and operating effectively in a protected environment. Recognizing this function allows for a better understanding of how aircraft components interact and the importance of structural design in aviation.