TURBINE ABRADABLE LAYER WITH PROGRESSIVE WEAR ZONE MULTI LEVEL RIDGE ARRAYS

摘要

Turbine and compressor casing abradable component embodiments for turbine engines, with composite grooves and vertically projecting alternating rows of first and second height ridges in planform patterns, to reduce, redirect and/or block blade tip airflow leakage downstream into the grooves rather than from turbine blade airfoil high to low pressure sides. The first ridges have a first ridge height greater than that of the second ridges. These ridge or rib embodiments have first lower and second upper wear zones. The lower zone, at and below the second ridge height, optimizes engine airflow characteristics, while the upper zone, between tips of the second and first ridges, is optimized to minimize blade tip gap and wear by being more easily abradable than the lower zone.