What happens to the velocity of air in the convergent duct of the CFM56-7B engine?

In the convergent duct of the CFM56-7B engine, the velocity of air increases as the air is compressed. This behavior is a fundamental principle of fluid dynamics known as the conservation of mass, which operates under the principle that as the cross-sectional area of a duct decreases, the velocity of the fluid passing through it must increase to maintain a constant mass flow rate.

In the specific case of a convergent duct, as the incoming air travels through the narrowing section, the reduction in area forces the air molecules to move faster. This increase in velocity occurs while the pressure decreases, aligning with Bernoulli’s principle that relates the pressure and velocity of fluid flow. Thus, as the air is compressed in the converging section of the duct, it accelerates, confirming that the correct answer related to the behavior of air velocity in this context is that it increases as it compresses.