An Experimental Study on Friction Contact Between Chamfered Labyrinth Fin and High Speed Rotor

This study reports an experimental work on friction contact between the chamfered labyrinth fin and high speed rotor at different incursion rates, final incursion depths, and sliding velocities. The small (original design case) and large specimens were selected to quantify the geometrical impact on the mass loss, plastic deformation, wear pattern, contact forces, and frictional temperature variations in the chamfered labyrinth fins. The results show that the contact-separations and contact force fluctuations are generated in rubbing events, which significantly affect the wear characteristics, contact forces, and temperature distributions for the small and large specimens. The abrasive and oxidation wears have pronounced influence on the wear behaviors of the tested specimen. At the same incursion condition, the mass loss percentages for the large specimen and small specimen are almost identical. As the sliding velocity increases from 55 m/s to 110 m/s, the mass loss percentage is decreased by 12–36%. For the large specimen, the mushrooming damage is mainly generated in the fin tip. The averaged frictional coefficient is 0.08–0.17, and the maximum temperature in the contact region is 640–700 °C. For the small specimen, the combined mushrooming and bending damage is generated in the labyrinth fin tip. The averaged frictional coefficient is 0.13–0.25, and the maximum temperature is 560–600 °C in the contact region. Due to the increased elasticity for the small specimen, the temperature fluctuation in the rubbing event is not as significant as the large one.