What is a potential downside of using vortex generators?

Using vortex generators can indeed lead to an increase in drag at high speeds, which is why this is considered a potential downside. Vortex generators are small aerodynamic surfaces attached to the wing or other surfaces of an aircraft to improve airflow and control. While they are effective at maintaining laminar flow and reducing stall characteristics at lower speeds, at higher speeds, the added surfaces can disrupt the airflow in a way that increases drag.

This increase in drag can result in a reduction in overall aerodynamic efficiency, which is important for performance, fuel consumption, and speed. Therefore, while vortex generators provide significant benefits in terms of flight stability and control at lower speeds, their impact on drag at higher speeds can be a disadvantage that pilots and engineers must consider when designing and operating an aircraft.