AERODYNAMICALLY MISTUNED AIRFOILS FOR UNSTEADY LOSS REDUCTION
Aerodynamically mistuned airfoils for unsteady loss reductions are disclosed herein. An example apparatus disclosed herein includes a disk, a first airfoil coupled to the disk, the first airfoil having a first geometry, and a second airfoil coupled to the disk adjacent to the first airfoil, the second airfoil having a second geometry different than the first geometry, the first airfoil and the second airfoil produce non-uniform wake passing times during operation of the disk.
1 . An apparatus comprising:
a disk;
a first airfoil coupled to the disk, the first airfoil having a first geometry and is spaced a first distance from an adjacent airfoil;
a second airfoil coupled to the disk adjacent to the first airfoil, the second airfoil having a second geometry and is spaced a second distance from the first airfoil;
a first channel between the first airfoil and the second airfoil; and
a second channel adjacent to the first channel, the first airfoil and the second airfoil producing non-uniform wake passing times in the first channel and the second channel during operation of the disk, wherein at least one of (1) the first geometry is different than the second geometry or (2) the first distance is different than the second distance.
2 . The apparatus of claim 1 , wherein the disk is a rotor disk of a gas turbine engine.
3 . The apparatus of claim 1 , further including a third airfoil coupled to the disk adjacent to the second airfoil, the third airfoil having a third geometry, the third geometry different than the second geometry.
4 . The apparatus of claim 1 , further including a third airfoil coupled to the disk adjacent to the second airfoil, the third airfoil having the first geometry.
5 . The apparatus of claim 4 , wherein:
the first distance is different than the second distance; and
the third airfoil is spaced a third distance from the second airfoil, the third distance different than the second distance and the first distance.
6 . The apparatus of claim 1 , wherein the first geometry includes a first thickness-to-chord ratio and the second geometry includes a second thickness-to-chord ratio, the first thickness-to-chord ratio different than the second thickness-to-chord ratio.
7 . The apparatus of claim 1 , wherein:
the first geometry includes having a first curvature with a corresponding first axial pressure distribution; and
the second geometry includes a second curvature with a corresponding second axial pressure distribution, the first axial pressure distribution different the second axial pressure distribution.
8 . The apparatus of claim 1 , wherein:
the first geometry includes a first thickness-to-chord ratio, the first geometry including a first curvature with a corresponding first axial pressure distribution; and
the second geometry includes a second thickness-to-chord ratio, the second geometry including a second curvature with a corresponding second axial pressure distribution, the first axial pressure distribution different the second axial pressure distribution.
9 . The apparatus of claim 1 , wherein:
the first geometry has a first chord length; and
the second geometry has a second chord length, the first chord length different than the second chord length.
10 . The apparatus of claim 1 , wherein the disk is a component of a low pressure turbine.
11 . A section of a gas turbine engine comprising:
a first row of airfoils; and
a second row of airfoils including:
a first airfoil having a first geometry and is spaced a first distance from an adjacent airfoil; and
a second airfoil disposed adjacent to the first airfoil, the second airfoil having a second geometry and is spaced a second distance from the first airfoil;
a first channel to receive first wake characteristics from the first row; and
a second channel to receive second wake characteristics from the first row, the first wake characteristics different than the second wake characteristics, wherein at least one of (1) the first geometry is different than the second geometry or (2) the first distance is different than the second distance.
12 . The section of claim 11 , wherein the first row is a stator row and the second row is a rotor row.
13 . The section of claim 11 , wherein the second row further includes a third airfoil adjacent to the second airfoil, the third airfoil having a third geometry, the third geometry different than the second geometry.
14 . The section of claim 11 , wherein the second row further includes a third airfoil adjacent to the second airfoil, the third airfoil having the first geometry.
15 . The section of claim 14 , wherein:
the first distance is different than the second distance; and
the third airfoil is spaced a third distance from the second airfoil, the third distance different than the second distance and the first distance.
16 . The section of claim 11 , wherein the first geometry includes a first thickness-to-chord ratio and the second geometry includes a second thickness-to-chord ratio, the first thickness-to-chord ratio different than the second thickness-to-chord ratio.
17 . The section of claim 11 , wherein:
the first geometry includes having a first curvature with a corresponding first axial pressure distribution; and
the second geometry includes a second curvature with a corresponding second axial pressure distribution, the first axial pressure distribution different the second axial pressure distribution.
18 . The section of claim 11 , wherein:
the first geometry includes a first thickness-to-chord ratio, the first geometry including a first curvature with a corresponding first axial pressure distribution; and
the second geometry includes a second thickness-to-chord ratio, the second geometry including a second curvature with a corresponding second axial pressure distribution, the first axial pressure distribution different the second axial pressure distribution.
19 . The section of claim 11 , wherein:
the first geometry has a first chord length; and
the second geometry has a second chord length, the first chord length different than the second chord length.
20 . The section of claim 11 , wherein the section is a low pressure turbine.