Experimental investigation into rubbing wear behaviors of flexible seals

This paper presents an experimental study on rubbing wear behaviors of flexible labyrinth seals with two inclined angles, i.e., α =27° (FS1) and α =49° (FS2). At two sliding velocities, three incursion depths and three incursion rates, the material loss, enlargement of sealing clearance and geometrical deformation for the flexible labyrinth seal were measured. The transient frictional temperature distributions and contact forces were monitored to analyze the coupled thermal-mechanical interactions in rubbing events. The results showed that In rubbing process, elastic deformation is dominating, while plastic deformation, abrasive wear and adhesive wear play important role on structural degradation. Mass loss is pronounced at the early stage of rub and increased with the increase of final incursion depth and relative rubbing distance. Sealing clearance enlargement after wear is significantly mitigated by the flexibility of seal fin, which enlarged by only 15%∼26% and 16%-32% for FS1 and FS2, respectively. The normal contact force on flexible labyrinth seals complies with the single-end loading rules of cantilever beam structure which is only affected by incursion depth and seal fin length. Additionally, the friction coefficient ranges between 0.25–0.45. Seal fin tip temperature shows high sensitivity with the contact strength. Where the maximum temperature at deepest incursion conditions of FS1 and FS2 distributes around 470 °C and 390 °C, respectively.