In some examples, article used as a component for a turbine engine that operates in a high temperature environment. The article may include: a ceramic or ceramic matrix composite (CMC) substrate; and a coating on the ceramic or the CMC substrate, wherein the coating defines an outer surface of the article. The coating includes a plurality of surface features defining channels on the outer surface of the article. The channels are configured to modify a flow of molten Calcia-Magnesia-Alumina Silicate (CMAS) over the outer surface of the coating in a gas flow over the outer surface of the article to reduce accumulation of the molten CMAS on the outer surface of the article.

A shaft for a gas turbine engine includes an inner contour with a stiffening rib that defines a stiffened wall thickness related to a nominal wall thickness according to a ratio between about 1.125-2.1.

A free-tipped axial fan assembly features a shroud barrel comprising an inlet, the radius of said inlet at its upstream end being greater than the radius of said inlet at its downstream end. An angle, in a plane including the fan axis, between the surface of said inlet and the direction of the fan axis varies non-monotonically with respect to a surface coordinate which increases with distance along the surface of the inlet.

A damper seal for a turbomachine includes an annular body having an inner circumferential surface and an outer circumferential surface separated by a thickness. As such, the inner circumferential surface may define a plurality of cavities arranged into a plurality of circumferential rows and at least one partition positioned between at least two of the plurality of cavities. In addition, the inner circumferential surface may further define at least one plenum arranged between two of the plurality of circumferential rows.

A hybrid three-layer system is presented. The hybrid three-layer system includes a two-layer composite system and an additively manufactured third layer comprising a lattice structure. The composite layer system includes a metallic substrate, a structured surface, and a thermal protection system. The structured surface may be additively manufactured onto the metallic substrate and includes structured surface features formed to project above the metallic substrate. Each of the structured surface features are separated from adjacent structured surface features by grooves. The thermal protection coating may be thermally sprayed onto the structured surface and is bonded to each of the structured surface features. The lattice structure is in contact with a surface of the metallic substrate of the composite layer system.

A method may comprise: laying up a first plurality of plies of material comprising thermoplastic resin and fiber to form an inner skin preform, the inner skin preform being a continuous sheet including alternating peaks and valleys; laying up a second plurality of plies of material comprising thermoplastic resin and fiber to form an outer skin preform; and joining the inner skin preform to the outer skin preform.

A composite layer system is presented. The composite layer system includes a metallic substrate, a structured surface, and a thermal protection system. The structured surface may be additively manufactured onto the metallic substrate and includes structured surface features formed to project above the metallic substrate. Each of the structured surface features are separated from adjacent structured surface features by grooves. The thermal protection coating may be thermally sprayed onto the structured surface and is bonded to each of the structured surface features.

A process for additively controlled surface features of a gas turbine engine casing. The process comprises forming the casing having an inner surface and an outer surface opposite the inner surface; forming a surface feature on the casing proximate the inner surface, wherein the surface feature comprises a structure on the inner surface configured to align or misalign with respect to a flow direction of a working fluid in a flow path of the casing.

A component stage for a turbomachine includes a component section. The component section includes a flowpath surface at least partially exposed to a core air flowpath defined by the turbomachine, when the component stage is installed in the turbomachine. The component further includes a plurality of sequentially arranged riblets on the flowpath surface, the plurality of sequentially arranged riblets customized for an anticipated location of the flowpath surface within the turbomachine by defining one or both of a non-uniform geometry or a non-uniform spacing.

A vane retainer for a gas turbine engine includes a retainer body, an inner surface of the retainer body to engage complimentary threads of a mating component, and a plurality of castellations located at an end of the retainer body for engagement with complementary installation tool features during installation of the vane retainer to the mating component. A gas turbine engine includes a combustor and a plurality of vane assemblies in fluid communication with the combustor. Each vane assembly includes a vane having an airfoil portion and a vane stem extending from the airfoil portion. The vane stem is inserted into a bushing. A vane retainer is engaged with the bushing and includes a retainer body, an inner surface of the retainer body to engage complimentary threads of the bushing, and a plurality of castellations located at an end of the retainer body for engagement with complementary installation tool features.