Abstract: A method and system adjusts blade tip clearance between rotating aircraft gas turbine engine blade tips and a surrounding shroud in anticipation of and before an engine command that changes an engine rotational speed. The method may include determining when to begin adjusting the tip clearance by expanding or contracting the shroud before the engine command and may be based on monitored aircraft and/or aircraft crew data indicative of the engine. The aircraft and/or aircraft crew data may include communications between aircraft crew and air traffic control authorities or air traffic control surrogates. Determining when to begin adjusting the tip clearance may include using learning algorithms which may use the aircraft gas turbine engine's operating experience and/or operating experience of other jet engines on an aircraft containing the aircraft gas turbine engine and/or on other aircraft.

Abstract: A multi sensor clearance probe with at least longitudinally and transversely spaced apart first and second sensors operable to measure first and second distances respectively between the sensors and a longitudinally spaced apart rotating rotor. The sensors being operable to measure blade tip clearances between radially outer turbine blade tips and an annular stator shroud circumscribing the blade tips. The blade tips may be squealer tips and the sensors operable to measure the distances between the sensors and tops of squealer tip walls and outwardly facing walls within cavities of the squealer tips. The probe may be operably connected to a controller for sending signals to the controller indicating the first and second distances for controlling an air valve used for active clearance control. Two or more of the probe may be used to determine rotor centerline offset.

Abstract: A gas turbine engine thermal control apparatus includes at least one annular spray tube having spray holes oriented to impinge thermal control air onto a fillet between an outer casing and a forward thermal control ring and, in a more particular embodiment, into a center of the fillet. The apparatus may include an annular segmented stator shroud attached to the outer casing and circumscribing radial outer blade tips of turbine blades of a turbine rotor. A thermal air distribution manifold encircling a portion of the outer casing includes an annular supply tube connected in fluid supply relationship to plenums of header assemblies. The annular spray tube is connected to at least one of the plenums and may be elongated radially inwardly and axially. Baffles attached to radially outwardly facing surfaces of the panels may be contoured to form exhaust passages having exhaust passage inlets and outlets between the baffles and the panels.

Abstract: A multi sensor clearance probe with at least longitudinally and transversely spaced apart first and second sensors operable to measure first and second distances respectively between the sensors and a longitudinally spaced apart rotating rotor. The sensors being operable to measure blade tip clearances between radially outer turbine blade tips and an annular stator shroud circumscribing the blade tips. The blade tips may be squealer tips and the sensors operable to measure the distances between the sensors and tops of squealer tip walls and outwardly facing walls within cavities of the squealer tips. The probe may be operably connected to a controller for sending signals to the controller indicating the first and second distances for controlling an air valve used for active clearance control. Two or more of the probe may be used to determine rotor centerline offset.

Abstract: A method and system adjusts blade tip clearance between rotating aircraft gas turbine engine blade tips and a surrounding shroud in anticipation of and before an engine command that changes an engine rotational speed. The method may include determining when to begin adjusting the tip clearance by expanding or contracting the shroud before the engine command and may be based on monitored aircraft and/or aircraft crew data indicative of the engine. The aircraft and/or aircraft crew data may include communications between aircraft crew and air traffic control authorities or air traffic control surrogates. Determining when to begin adjusting the tip clearance may include using learning algorithms which may use the aircraft gas turbine engine's operating experience and/or operating experience of other jet engines on an aircraft containing the aircraft gas turbine engine and/or on other aircraft.