Which turbine component dampens blade vibration by forming a band around the blade tips?

Which turbine component dampens blade vibration by forming a band around the blade tips?

• A. Dovetail
• B. Casing
• C. Rotor blade
• D. Shrouding

Answer: (D)

Damping blade vibration is achieved by shrouding, which forms a band around the blade tips to couple them and dissipate vibrational energy. When the blades experience bending vibrations, the tips would otherwise move out of sync; the shroud ring around the tips creates a damping path, so the blades rub or interact with the shroud and neighboring tips. This rubbing converts some of the vibrational energy into heat, reducing the vibration amplitude, improving flutter stability, and extending blade life. The other components have different roles: the dovetail is the root attachment securing the blade to the disk, the casing is the outer housing that supports the whole assembly, and the rotor blade is simply the vibrating element itself without the tip-damping band.

Damping blade vibration is achieved by shrouding, which forms a band around the blade tips to couple them and dissipate vibrational energy. When the blades experience bending vibrations, the tips would otherwise move out of sync; the shroud ring around the tips creates a damping path, so the blades rub or interact with the shroud and neighboring tips. This rubbing converts some of the vibrational energy into heat, reducing the vibration amplitude, improving flutter stability, and extending blade life. The other components have different roles: the dovetail is the root attachment securing the blade to the disk, the casing is the outer housing that supports the whole assembly, and the rotor blade is simply the vibrating element itself without the tip-damping band.