Patent ID: 8439626

Claim:
An assembly of airfoils in a compressor of a turbine engine, the assembly comprising at least three axially stacked rows of airfoils: a middle airfoil row, a first upstream airfoil row, and a first downstream airfoil row; wherein: the middle airfoil row is bordered on each side by the first upstream airfoil row, which comprises the first row of airfoils in the upstream direction from the middle airfoil row, and the first downstream airfoil row, which comprises the first row of airfoils in the downstream direction from the middle airfoil row; the first upstream airfoil row and the first downstream airfoil row have substantially the same number of similarly shaped airfoils; the first upstream airfoil row and the first downstream airfoil row each comprise a row of rotor blades, which rotate at substantially the same speed during operation; the middle airfoil row comprises a row of stator blades, which remains substantially stationary during operation; at least 90% of the airfoils of the first upstream airfoil row and at least 90% of the airfoils of the first downstream airfoil row comprise a clocking relationship of between 25% and 75% pitch; further comprising a second upstream airfoil row, which borders the first upstream airfoil row and comprises the second row of airfoils in the upstream direction from the middle airfoil row; and a third upstream airfoil row, which borders the second upstream airfoil row and comprises the third row of airfoils in the upstream direction from the middle airfoil row; wherein the third upstream airfoil row, the first upstream airfoil row, and the first downstream airfoil row have substantially the same number of similarly shaped airfoils; wherein the third upstream airfoil row, the first upstream airfoil row, and the first downstream airfoil row each comprise a row of rotor blades, which rotate at substantially the same speed during operation; wherein the second upstream airfoil row comprises a row of stator blades, which remain substantially stationary during operation; and wherein at least 90% of the airfoils of the third upstream airfoil row and at least 90% of the airfoils of the first upstream airfoil row comprise a clocking relationship of between 25% and 75% pitch.