The Influence of the Axial Rub Added in the Radial Rub on the Wear of the Seal Fins during the High Speed Rub of Labyrinth-Honeycomb Seal

Abstract

Labyrinth-honeycomb seals are a state-of-the-art sealing technology commonly used in aero-engine interstage seal. The undesirable severe rub between the seal fins and the honeycomb due to the clearance change may induce the cracking of the seal fins. A pervious study investigated the wear of the seal fins at different radial incursion rates. However, due to the axial thrust and mounting clearance, the axial rub between the seal fins and the honeycomb may occur. Hence, this paper focuses on the influence of the axial rub added in the radial rub on the wear of the seal fins. The rub tests results, including rubbing forces and temperature, wear rate, worn morphology, cross-sectional morphology and energy dispersive spectroscopy results, are presented and discussed. Overall, the participation of the axial rub leads to higher rubbing forces, temperature, and wear rate. The tribo-layer on the seal fin is thicker and the cracks are more obvious at high axial incursion rate. These phenomena indicate the axial rub has a negative influence on the wear of the seal fins and should be avoided.

Experimental Study on the Effect of Rubbing Mode on Radial Crack Initiation in Labyrinth Seal Fins of Shrouded Turbine Blade

“…A comprehensive comparison of Figure 9b,d,f,h,j shows that the radial force is significantly greater than the axial force, which is the same as the test results in references [13,22]. Comparing the effects of radial force, axial force, and tangential force on temperature, the effect of tangential force on temperature is not obvious, which can be seen in radial rubbing and axial radial rubbing, when the tangential force is maximum, the temperature does not rise significantly.…”

“…The participation of axial rubbing can lead to higher rubbing force, rubbing temperature, and wear rate. At a higher axial incursion rate, the rubbing layer on the fin is thicker and the crack is more obvious [22].…”

CFD-Predicted Rotordynamic Characteristics for High-Temperature Water Liquid Seal Considering Tooth Deformation

“…There are now many novel seal structures in the field of rotating machinery research, such as labyrinth-honeycomb seal, the pocket damper seal, the labyrinth seal with staggered helical teeth (SHT) structure, etc. [9][10][11]. Zhang et al [12] proposed a novel anti-stagnation labyrinth seal structure.…”