Combustion liner for gas turbine engine
A liner for a combustion section of a gas turbine engine includes a base portion and a stiffening portion. The base portion includes a plurality of plies of a composite material including a first ply having a fiber direction aligned with a circumferential direction of the liner and a second ply adjacent to the first ply, the second ply having a fiber direction angled away from the circumferential direction. The stiffening portion is disposed on the base portion and includes a plurality of plies of the composite material including a first ply having a fiber direction aligned with the circumferential direction, a second ply adjacent to the first ply the second ply having a fiber direction aligned with the circumferential direction, and a third ply adjacent to the second ply, the third ply having a fiber direction angled away from the circumferential direction.
1 . A liner for a combustion section of a gas turbine engine, the liner defining a circumferential direction and an axial direction from a forward end to an aft end, the liner comprising:
a base portion comprising a first plurality of plies of a composite material, the base portion defining an inner surface of a combustion chamber; and
a stiffening portion comprising a second plurality of plies of the composite material, the stiffening portion disposed on the base portion,
wherein the first plurality of plies of the base portion of the liner include a pair of plies including a first ply having a first fiber direction aligned with the circumferential direction and a second ply adjacent to the first ply of the pair of plies, the second ply of the pair of plies having a second fiber direction angled away from the circumferential direction,
wherein the second plurality of plies of the stiffening portion of the liner include a set of plies including a first ply having the first fiber direction aligned with the circumferential direction, a second ply adjacent to the first ply of the set of plies, the second ply of the set of plies having the first fiber direction aligned with the circumferential direction, and a third ply adjacent to the second ply of the set of plies, the third ply of the set of plies having the second fiber direction angled away from the circumferential direction,
wherein the stiffening portion extends in the axial direction from a forward end to an aft end,
wherein the forward end of the stiffening portion is disposed at an axial position in the liner at or aft of 50% of a length of the liner in the axial direction from the forward end of the liner, and wherein a length of the stiffening portion is at least 10% of the length of the liner in the axial direction,
wherein the aft end of the stiffening portion is disposed forward of the aft end of the liner, and
wherein a thickness of the liner from the inner surface to a cold side of the liner smoothly transitions from a first thickness at the forward end of the stiffening portion to a second thickness, the second thickness extending aft in a continuous manner to and terminating at a location where the liner smoothly transitions from the second thickness to the first thickness at the aft end of the stiffening portion.
2 . The liner of claim 1 , wherein the first plurality of plies of the base portion include a plurality of the pair of plies, each one of the plurality of the pair of plies adjacent to another of the plurality of the pair of plies.
3 . The liner of claim 1 , wherein the first plurality of plies of the base portion are arranged such that the first and second fiber directions of the first plurality of plies of the base portion alternate between the first fiber direction aligned with the circumferential direction and the second fiber direction angled away from the circumferential direction.
4 . The liner of claim 1 , wherein the second plurality of plies of the stiffening portion include a plurality of the set of plies, each one of the plurality of the set of plies adjacent to another of the plurality of the set of plies.
5 . The liner of claim 1 , wherein the set of plies includes a fourth ply disposed beneath the first ply of the set of plies, the fourth ply of the set of plies having the first fiber direction aligned with the circumferential direction.
6 . The liner of claim 1 , further comprising a covering portion disposed on the stiffening portion.
7 . The liner of claim 1 , wherein the second fiber direction of the second ply of the pair of plies is perpendicular to the circumferential direction.
8 . The liner of claim 1 , wherein the second fiber direction of the third ply of the set of plies is perpendicular to the circumferential direction.
9 . The liner of claim 1 , wherein the length of the stiffening portion is less than or equal to 45% of the length of the liner in the axial direction.
10 . A method for forming a liner for a combustion section of a gas turbine engine, the liner defining a circumferential direction and an axial direction from a forward end to an aft end, the method comprising:
laying up a plurality of plies of a composite material to form a base portion of the liner, the base portion defining an inner surface of a combustion chamber, wherein the plurality of plies include a pair of plies including a first ply having a first fiber direction aligned with the circumferential direction and a second ply adjacent to the first ply of the pair of plies, the second ply having a second fiber direction angled away from the circumferential direction; and
laying up a plurality of sets of plies of the composite material on the base portion to form a stiffening portion of the liner, each set of the plurality of sets of plies including a first ply, a second ply adjacent to and exterior to the first ply of the plurality of sets of plies, and a third ply adjacent to and exterior to the second ply of the plurality of sets of plies,
wherein, within each set, the first ply of each of the plurality of sets of plies has the first fiber direction aligned with the circumferential direction, the second ply of each of the plurality of sets of plies has the first fiber direction aligned with the circumferential direction, and the third ply of each of the plurality of sets of plies has the second fiber direction angled away from the circumferential direction,
wherein the stiffening portion extends in the axial direction from a forward end to an aft end,
wherein the forward end of the stiffening portion is disposed at an axial position in the liner at or aft of 50% of a length of the liner in the axial direction from the forward end of the liner, and wherein a length of the stiffening portion is at least 10% of the length of the liner in the axial direction,
wherein the aft end of the stiffening portion is disposed forward of the aft end of the liner, wherein a thickness of the liner from the inner surface to a cold side of the liner smoothly transitions from a first thickness at the forward end of the stiffening portion to a second thickness, the second thickness extending aft in a continuous manner to and terminating at a location where the liner smoothly transitions from the second thickness to the first thickness at the aft end of the stiffening portion.
11 . The method of claim 10 , further comprising laying up a second plurality of plies on the stiffening portion to form a covering portion such that the respective fiber directions of adjacent plies of the second plurality of plies alternate between the first fiber direction aligned with the circumferential direction and the second fiber direction angled away from the circumferential direction.
12 . The method of claim 10 , wherein the fiber direction of the third ply of each set of the plurality of sets of plies is perpendicular to the circumferential direction.
13 . The method of claim 10 , wherein at least one of the plurality of sets of plies includes a fourth ply laid up between the second ply of the at least one of the plurality of sets of plies and the third ply of the at least one of the plurality of sets of plies, the fourth ply of the at least one of the plurality of sets of plies having the first fiber direction aligned with the circumferential direction.
14 . The method of claim 10 , wherein the length of the stiffening portion is less than or equal to 45% of the length of the liner in the axial direction.
15 . A gas turbine engine comprising:
a compressor section;
a combustion section downstream of the compressor section; and
a turbine downstream of the combustion section,
wherein the combustion section includes a liner defining a circumferential direction and an axial direction from a forward end of the liner to an aft end of the liner, the liner comprising:
a base portion comprising a first plurality of plies of a composite material, the base portion defining an inner surface of a combustion chamber, the first plurality of plies arranged adjacent to one another and defining a first pattern of fiber directions; and
a stiffening portion comprising a second plurality of plies of the composite material, the stiffening portion disposed on the base portion and extending 360 degrees about the axial direction, the second plurality of plies arranged adjacent to one another and defining a second pattern of fiber directions different from the first pattern of fiber directions,
wherein the stiffening portion extends in the axial direction from a forward end of the stiffening portion to an aft end of the stiffening portion,
wherein the forward end of the stiffening portion is disposed at an axial position in the liner at or aft of 50% of a length of the liner in the axial direction from the forward end of the liner, and wherein a length of the stiffening portion is at least 10% of the length of the liner in the axial direction,
wherein the aft end of the stiffening portion is disposed forward of the aft end of the liner,
wherein a thickness of the liner from the inner surface to a cold side of the liner smoothly transitions from a first thickness at the forward end of the stiffening portion to a second thickness, the second thickness extending aft in a continuous manner to and terminating at a location where the liner smoothly transitions from the second thickness to the first thickness at the aft end of the stiffening portion.
16 . The gas turbine engine of claim 15 , wherein the first pattern of fiber directions is a set of fiber directions in a sequence of:
a first fiber direction aligned with the circumferential direction, and
a second fiber direction angled away from the circumferential direction.
17 . The gas turbine engine of claim 15 , wherein the second pattern of fiber directions is a set of fiber directions in a sequence of:
a first fiber direction aligned with the circumferential direction,
the first fiber direction aligned with the circumferential direction, and
a second fiber direction angled away from the circumferential direction.
18 . The gas turbine engine of claim 15 , wherein the first pattern of fiber directions is a 0/90 pattern, and the second pattern of fiber directions is a 0/0/90 pattern or a 0/0/0/90 pattern.
19 . The gas turbine engine of claim 15 , wherein the length of the stiffening portion is less than or equal to 45% of the length of the liner in the axial direction.