Patent ID: 7614847

Claim:
A pattern for improving aerodynamic performance of a turbine comprising: a material disposed at a base surface disposed at an interior surface of a turbine shroud such that said material is capable of abradable contact with a tip portion of a turbine bucket, said material disposed in a pattern, wherein said pattern comprises, a first plurality of ridges disposed at said base surface such that at least a first portion of said first plurality of ridges corresponding to at least a back portion of said turbine bucket is oriented at a first angle with respect to an axis of rotation of said turbine bucket, each ridge of said first plurality of ridges defined by a first sidewall and a second sidewall, said first and second sidewalls each having a first end and an opposite second end, said first end of said first and second sidewalls extending from said base surface, said first and second sidewalls sloping toward each other until meeting at said second ends of respective first and second sidewalls defining a centerline and a top portion of said ridge, said first and second sidewalls are inclined with substantially equal but opposite slopes with respect to said base surface, wherein said first plurality of ridges extends to a second portion of said first plurality of ridges corresponding to a front portion of said turbine bucket, said second portion defining a curved section of said first plurality of ridges.