Final answer:
Rotor blades in an axial compressor rotate to extract energy and increase velocity, while stator blades redirect the fluid flow and increase pressure.
Step-by-step explanation:
In an axial compressor, the purpose of rotor blades is to rotate and extract energy from the fluid medium by increasing its velocity. The increased velocity leads to a decrease in pressure, creating compression. The rotor blades are designed like airplane wings and can be rotated on an axis, allowing them to engage the fluid at different angles to vary efficiency.
On the other hand, stator blades in an axial compressor are stationary and serve to redirect the fluid flow from the rotor blades. They help to further increase the pressure by diffusing the fluid and converting its high velocity into increased pressure. The stator blades guide the fluid to the next set of rotating rotor blades, continuing the process of compression.