Aviation Machinist Mate (AD) Week 1 Practice Test

Exit guide vanes are stationary blades placed after the compressor rotor to straighten the swirling air coming off the rotor. The rotor imparts a swirl to the flow, and these vanes remove that tangential component, turning it into a more axial flow entering the diffuser or the next stage. This straightening reduces turbulence and flow separation, improves pressure recovery, and leads to smoother, more efficient operation downstream. They don’t create a notable pressure gain by themselves—the pressure rise mainly comes from the compressor stages—not from the vanes. They also don’t mix fuel with air or cool the air.