The addition of vortex generators typically leads to what change in aerodynamic efficiency?

The addition of vortex generators typically leads to a decrease in drag, which improves the aircraft's aerodynamic efficiency. Vortex generators are small aerodynamic surfaces attached to the wings and other surfaces of an aircraft. Their primary function is to control airflow around the wings and to enhance the effectiveness of the wing by delaying flow separation.

When airflow remains attached to the wing surface for a longer period, it allows the aircraft to maintain lift at higher angles of attack, effectively increasing the stall angle and improving overall stability. This improved airflow management reduces the formation of turbulent wake behind the aircraft, leading to a reduction in induced drag. Consequently, the aircraft can achieve better performance and fuel efficiency.

In contrast, the other options do not accurately describe the primary benefit of vortex generators. While it's true that they add some weight to the aircraft structure, their aerodynamic benefits generally outweigh this drawback. Thus, while vortex generators increase some aspects of drag indirectly associated with their mass, the overall aerodynamic efficiency primarily reflects a reduction in drag through improved airflow control.