Abstract: A method of reinforcing a ceramic sandwich structure includes forming a ceramic core, assembling the sandwich structure by disposing the core between and in physical contact with a first panel and a second panel, and weaving a plurality of z-fibers at least partially through a thickness of the sandwich structure.

Abstract: A method of forming a ceramic matrix composite includes fabricating a space filling insert by assembling the space filling insert from a fibrous ceramic material, placing the space filling insert into a tooling fixture, the tooling fixture having an internal shape complementary to a shape of the insert, and infiltrating the space filling insert with a first ceramic material. The method further includes forming a preform by laying up a plurality of fibrous ceramic plies and inserting the infiltrated space filling insert into a void defined by the plurality of plies. The method further includes infiltrating the preform with a second ceramic material.

Abstract: A flange stiffener support for a duct in a gas turbine engine includes a circumferential flange segment that has a plurality of flange fastener openings. An axial body segment extends from a radially inner side of the circumferential segment and has at least one body fastener opening. The axial body segment extends at least partially along a circumferential distance of the circumferential flange segment.

Abstract: An airfoil includes an airfoil wall that circumscribes a main cavity and defines radially inner and outer ends, leading and trailing edges, and pressure and suction sides. The airfoil wall includes a lay-up of ceramic matrix composite (CMC) plies that span the radially inner and outer ends and have an inner-most CMC ply bounding at least a portion of the main cavity, an exterior skin CMC ply, and intermediate CMC plies between the inner-most CMC ply and the exterior skin CMC ply. At least one of the intermediate CMC plies has cutout voids that define cooling channels in the airfoil wall. The cooling channels are bound on lateral sides by the at least one of the intermediate CMC plies, bound on an inner side by a first adjacent one of the CMC plies, and bound on an outer side by a second, different adjacent one of the CMC plies.

Abstract: A preform comprising a first sub-laminate comprising a plurality of layers and a second sub-laminate comprising a plurality of layers. The first sub-laminate comprises a first unit cell comprising a first volume fraction of tows, where the first volume fraction of tows comprise first tows having a first tow spacing between successive first tows. The second sub-laminate comprises a second unit cell comprising a second volume fraction of tows, where the second volume fraction of tows comprise second tows having a second tow spacing between successive second tows. The first volume fraction of tows in the first unit cell is equal to the second volume fraction of tows in the second unit cell. The second tow spacing is less than the first tow spacing.

Abstract: A ceramic matrix composite laminate comprises a ceramic matrix that encapsulates a plurality of layers. Each layer comprises fibers. Each layer comprises a plurality of fill fibers and a plurality of warp fibers or a plurality of bias fibers. The outermost layer contains a different concentration of fibers per unit volume than a layer located near an interior of the ceramic matrix composite laminate. A gradient in the number of fibers exists between the outermost layer and the layer located at the interior of the ceramic matrix composite laminate, or a combination thereof. A combined ceramic matrix composite comprises a plurality of composite laminates; wherein each laminate has a different fiber concentration gradient from another laminate that it is in contact with.

Abstract: A ceramic matrix composite airfoil includes a high-pressure surface and a low-pressure surface connected at a leading edge and a trailing edge. The high-pressure surface and the low-pressure surface extend from a first end to a second end. A leading edge cooling passage includes an inlet portion, a midspan portion and an outlet portion. A cross-sectional flow area of the midspan portion is less than a cross-sectional flow area of either the inlet portion or the outlet portion.

Abstract: A seal arc segment includes a wall that defines radially inner and outer sides, forward and aft ends, and first and second circumferential sides. The wall includes a CMC ply lay-up of a radially inner-most CMC ply on the inner side, a radially outer-most CMC ply on the radially outer side, and radially intermediate CMC plies therebetween. At least one of the radially intermediate CMC plies has cutout voids that define cooling channels in the wall. The cooling channels are bound on lateral channel sides by the at least one of the radially intermediate CMC plies, bound on a radially inner channel side by a first adjacent one of the CMC plies, and bound on a radially outer channel side by a second, different adjacent one of the CMC plies. The radially outer-most CMC ply includes at least one inlet hole connected to the cooling channels for providing cooling air.

Abstract: A method includes forming an airfoil, where the airfoil includes an airfoil wall that has a span between first and second radial ends and defines leading and trailing edges, pressure and suction sides each join the leading and trailing edges, and an internal cavity, the internal cavity is divided into at least first and second sub-cavities that extend over the span, and the first sub-cavity defines a venturi tube. The forming includes i) fabricating a fiber preform of the airfoil around a plurality of mandrels, wherein the mandrel in the first sub-cavity is radially split, and ii) densifying the fiber preform with a ceramic matrix. The airfoil may include an internal cavity that is divided into at least first and second sub-cavities extending over the span, where the first sub-cavity defines a venturi tube.

Abstract: An airfoil for a gas turbine engine includes an airfoil section and a platform that has a non-gaspath side and a gaspath side from which the airfoil section extends. The platform is comprised of a sandwich composite that has first and second ceramic matrix composite (CMC) skins that each include at least one 2-D ceramic fiber ply. The first and second CMC skins are disposed, respectively, on the gaspath side and the non-gaspath side, and there is a cellular core disposed radially between the first and second CMC skins.

Abstract: A gas turbine engine component includes an airfoil body extending between a leading edge and a trailing edge and having a suction wall and a pressure wall. An outer surface of the airfoil body is formed by an outer coat defining around the pressure and suction sides, a leading edge and a trailing edge. An internal cross-rib is formed within a cavity in the airfoil body. The internal cross-rib extends to be secured to the outer coat adjacent the leading edge and the trailing edge, and extending across the internal cavity to form a junction such that the cross-rib is x-shaped. The outer coat and the cross-rib are formed of ceramic matrix composites. A gas turbine engine is also disclosed.

Abstract: A gas turbine engine stator vane combination includes a stator vane body having an airfoil with a leading edge, a trailing edge, a suction side and a pressure side, and having at least one internal cooling channel. The stator vane body is formed of ceramic matrix composite materials. A spar is received within the at least one cooling air channel and formed of a metal. The spar has an outer peripheral surface spaced from an inner peripheral surface of the cooling air channel to define a cooling air path, with the cooling air path having a varying cross-sectional area through the cooling air channel. A gas turbine engine is also disclosed.

Abstract: A flange stiffener support for a duct in a gas turbine engine includes a circumferential flange segment that has a plurality of flange fastener openings. An axial body segment extends from a radially inner side of the circumferential segment and has at least one body fastener opening. The axial body segment extends at least partially along a circumferential distance of the circumferential flange segment.

Abstract: A gas turbine engine stator vane combination includes a stator vane body having an airfoil with a leading edge, a trailing edge, a suction side and a pressure side, and having at least one internal cooling channel. The stator vane body is formed of ceramic matrix composite materials. A spar is received within the at least one cooling air channel and formed of a metal. The spar has an outer peripheral surface spaced from an inner peripheral surface of the cooling air channel to define a cooling air path, with the cooling air path having a varying cross-sectional area through the cooling air channel. A gas turbine engine is also disclosed.

Abstract: A method of forming a ceramic matrix composite airfoil includes forming a fibrous ceramic preform by laying up a plurality of plies to form a hollow core cavity, overwrapping the plurality of plies of the core cavity with a first overwrap layer, weaving together a tows of first free portion and tows of a second free portion of the first overwrap layer to form a cross brace, overwrapping the plurality of plies of the core cavity and the first overwrap layer with a second overwrap layer, and consolidating the first free portion and the second free portion of the first overwrap layer and a third free portion and a fourth free portion of the second overwrap layer to form a trailing edge.

Abstract: An airfoil includes an airfoil wall that has a span between first and second radial ends and that defines leading and trailing edges, pressure and suction sides each joining the leading and trailing edges, and an internal cavity. The internal cavity is divided into at least first and second sub-cavities extending over the span. The first sub-cavity defines a venturi tube.

Abstract: A ceramic matrix composite airfoil includes a high-pressure surface and a low-pressure surface connected at a leading edge and a trailing edge. The high-pressure surface and the low-pressure surface extend from a first end to a second end. A leading edge cooling passage includes an inlet portion, a midspan portion and an outlet portion. A cross-sectional flow area of the midspan portion is less than a cross-sectional flow area of either the inlet portion or the outlet portion.

Abstract: An assembly for a gas turbine engine according to an aspect of the present disclosure includes a metallic damper including a first contact surface and a gas turbine engine component. The gas turbine engine component includes a main body extending in a first direction between a gaspath surface and a second contact surface. The first and second contact surfaces oppose each other along an interface extending in a second direction. The first and second contact surfaces are dimensioned to contact each other along the interface in a hot assembly state. The main body is established by a composite including fibers in a matrix material. At least some of the fibers are arranged to establish a plurality of cooling passages aligned with the interface relative to the second direction. A method of damping for a gas turbine engine is also disclosed.

Abstract: A ceramic matrix composite airfoil includes a high-pressure surface and a low-pressure surface connected at a leading edge and a trailing edge. The high-pressure surface and the low-pressure surface extend from a first end to a second end. A leading edge cooling passage includes an inlet portion, a midspan portion and an outlet portion. A cross-sectional flow area of the midspan portion is less than a cross-sectional flow area of either the inlet portion or the outlet portion.

Abstract: A method of forming a ceramic matrix composite airfoil includes forming a fibrous ceramic preform by laying up a plurality of plies to form a hollow core cavity, overwrapping the plurality of plies of the core cavity with a first overwrap layer, weaving together a tows of first free portion and tows of a second free portion of the first overwrap layer to form a cross brace, overwrapping the plurality of plies of the core cavity and the first overwrap layer with a second overwrap layer, and consolidating the first free portion and the second free portion of the first overwrap layer and a third free portion and a fourth free portion of the second overwrap layer to form a trailing edge.