In an axial-flow compressor, one purpose of the stator vanes at the discharge end of the compressor is to

In an axial-flow compressor, one purpose of the stator vanes at the discharge end of the compressor is to

• A. Straighten the airflow and eliminate turbulence
• B. Increase the velocity and prevent swirling and eddying
• C. Decrease the velocity, prevent swirling and decrease pressure
• D. Support the housing and bearings

Answer: (A)

Discharging stator vanes are used to straighten the flow after the rotor and remove the swirl that the rotor introduces. By redirecting the swirling air into a uniform axial direction, the flow becomes steadier and enters the next stage more efficiently. They also act as a diffuser, converting some of the flow’s velocity into static pressure, which raises the pressure without increasing swirl. This combination—straightening the flow and improving pressure—is what makes the discharge stator vanes effective. That's why the option describing straightening the airflow and eliminating swirl best fits. Increasing velocity or decreasing pressure would not align with the stator’s role, and providing structural support for the housing isn’t its function.

Discharging stator vanes are used to straighten the flow after the rotor and remove the swirl that the rotor introduces. By redirecting the swirling air into a uniform axial direction, the flow becomes steadier and enters the next stage more efficiently. They also act as a diffuser, converting some of the flow’s velocity into static pressure, which raises the pressure without increasing swirl. This combination—straightening the flow and improving pressure—is what makes the discharge stator vanes effective.

That's why the option describing straightening the airflow and eliminating swirl best fits. Increasing velocity or decreasing pressure would not align with the stator’s role, and providing structural support for the housing isn’t its function.