Patent ID: 7600968

Claim:
An article of manufacture comprising: a material disposed in a pattern, wherein said pattern comprises: a first plurality of ridges disposed at a base surface of a turbine, 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 at least a first portion of said first plurality of ridges corresponding to at least a back portion of a turbine bucket is oriented at a first angle with respect to an axis of rotation of said turbine bucket; wherein said first angle ranges from about 20 degrees to about 70 degrees; wherein said pattern includes said first plurality of ridges disposed at said base surface such that said each ridge of said first plurality of ridges is substantially parallel to each other; and wherein said first angle is equal to an exit angle of a trailing edge of said turbine bucket.