Method for controlling a clearance between the tips of the blades of a rotor of an aircraft engine turbine and a turbine ring, comprising the estimation of the clearance to be controlled and the control of a valve delivering an air stream directed towards the turbine ring based on the thus estimated clearance, this method comprising: the detection of a transient acceleration phase based on at least one parameter representative of the engine; the receipt of a data relating to the altitude of the aircraft; the determination of data representative of the temperature of the rotor during the transient acceleration phase and in steady speed and the calculation of a relative temperature deviation.

A turbine module (2) for a turbomachine (1). The turbine module (2) includes a main channel (26) to guide a main flow (36) through the turbine module (2), a rotor blade (21) and a stator vane (22), the stator vane (22) including a stator airfoil (22) and a platform (23), with the stator airfoil (22) arranged downstream of the rotor blade (21) in the main channel (26), and a cavity (30) including an inlet (31) for injecting a part (36.2) of the main flow (36) into the cavity (30), an outlet (32) for a reinjection of the part (36.2) of the main flow (36) from the cavity (30) into the main channel (26), wherein the cavity (30) is arranged at an axial position of the stator vane (20) and is radially offset from the stator airfoil (22).

A turbine module (2) for a turbomachine (1). The turbine module (2) includes a main channel (26) to guide a main flow (36) through the turbine module (2), a rotor blade (21) and a stator vane (22), the stator vane (22) including a stator airfoil (22) and a platform (23), with the stator airfoil (22) arranged downstream of the rotor blade (21) in the main channel (26), and a cavity (30) including an inlet (31) for injecting a part (36.2) of the main flow (36) into the cavity (30), an outlet (32) for a reinjection of the part (36.2) of the main flow (36) from the cavity (30) into the main channel (26), wherein the cavity (30) is arranged at an axial position of the stator vane (20) and is radially offset from the stator airfoil (22).

A turbine assembly in a turbine section of an aircraft engine includes a rotor with blades having blade tips, and a turbine housing radially surrounding the blades. A distance between an inner surface of the housing and the blade tips defines a tip clearance gap. A passive cooling system for optimizing the tip clearance gap includes a cooling airflow passage located radially outward from, and in heat-transfer with, the turbine housing. The cooling airflow passage has an inlet opening located upstream of the rotor and an exit opening located downstream of the rotor. The inlet opening provides air flow into the cooling airflow passage. The exit opening provides air flow communication between the cooling airflow passage and a main gaspath of the turbine section. A flow of cooling air through the cooling airflow passage is induced, to cool the housing.

Methods, apparatus, systems and articles of manufacture are disclosed. A shroud assembly of a gas turbine engine includes: a first shroud arm having a first end and a second end, the first end to couple to an outer wall and the second end to couple to a first shroud pad, and a second shroud arm having a first end and a second end, the first end to couple to the outer wall and the second end to couple to a second shroud pad, at least one of the first shroud pad or the second shroud pad to move radially outward toward the outer wall in response to a rotor blade contacting the at least one of the first shroud pad or the second shroud pad.

An example high-performance system includes an example high-performance component including a substrate and a multilayer abradable track adjacent to the substrate. The abradable track includes a plurality of alternating layers along a thickness of the abradable track. The plurality of alternating layers includes at least one relatively porous abradable layer and at least one relatively dense layer. A porosity of the relatively dense layer is lower than that of the at least one relatively porous abradable layer. The example high-performance system may include a rotating component configured to contact and abrade the multilayer abradable track. An example technique for forming the multilayer abradable track includes thermal spraying a first precursor composition toward the substrate to form a relatively porous abradable layer of a layer pair of a plurality of layer pairs of the multilayer abradable track, and a second precursor composition to form a relatively dense layer of the pair.

An example high-performance system includes an example high-performance component including a substrate and a multilayer abradable track adjacent to the substrate. The abradable track includes a plurality of alternating layers along a thickness of the abradable track. The plurality of alternating layers includes at least one relatively porous abradable layer and at least one relatively dense layer. A porosity of the relatively dense layer is lower than that of the at least one relatively porous abradable layer. The example high-performance system may include a rotating component configured to contact and abrade the multilayer abradable track. An example technique for forming the multilayer abradable track includes thermal spraying a first precursor composition toward the substrate to form a relatively porous abradable layer of a layer pair of a plurality of layer pairs of the multilayer abradable track, and a second precursor composition to form a relatively dense layer of the pair.

A gas turbine engine includes a ceramic wall for bounding an engine core gas path. The ceramic wall has a ceramic wall first side that faces the engine core gas path and a ceramic wall second side that faces away from the engine core gas path. There is a metallic wall adjacent the ceramic wall second side. The metallic wall has a metallic wall first side that faces the ceramic wall and a metallic wall second side that faces away from the ceramic wall. The metallic wall and the ceramic wall are spaced apart such that there is a channel there between. There is a seal on the ceramic wall second side, and the metallic wall has at least one cooling hole adjacent the seal for emitting cooling air to cool the seal.

A gas turbine engine includes a ceramic wall for bounding an engine core gas path. The ceramic wall has a ceramic wall first side that faces the engine core gas path and a ceramic wall second side that faces away from the engine core gas path. There is a metallic wall adjacent the ceramic wall second side. The metallic wall has a metallic wall first side that faces the ceramic wall and a metallic wall second side that faces away from the ceramic wall. The metallic wall and the ceramic wall are spaced apart such that there is a channel there between. There is a seal on the ceramic wall second side, and the metallic wall has at least one cooling hole adjacent the seal for emitting cooling air to cool the seal.

A shaft assembly for use with a turbine engine includes a shaft and a magnetic mode control unit. The shaft extends along an axis and is configured to rotate about the axis. The magnetic mode control unit is configured to control deflection of the shaft as the shaft rotates about the axis.