TIP CLEARANCE CONTROL FOR TURBINE BLADES

摘要

A carrier segment of a carrier section for circumscribing an array of circumferentially spaced turbine blades of a gas turbine engine, the blades being disposed radially inwardly of a turbine casing, the carrier segment including a carrier wall disposed radially inwardly of the casing and radially outwardly of the turbine blades, and the carrier wall including one or more portions facing the casing, wherein at least one of the one or more portions of the carrier wall is provided with one or more impingement apertures therein for passage therethrough of air of a predetermined temperature, heating air, from a feed source into impingement onto the turbine casing. The application of heating air onto the casing during transient stages of enhanced engine power, e.g. during step climbs, results in better matching of radial expansion of the casing relative to the turbine blades, thereby enabling improved blade tip clearance control.

主权项

1. A carrier segment of a carrier section for circumscribing an array of circumferentially spaced turbine blades of a gas turbine engine, the blades being disposed radially inwardly of a turbine casing,
the carrier segment including a carrier wall disposed radially inwardly of the casing and radially outwardly of the turbine blades, and the carrier wall comprising one or more portions facing the casing, wherein at least one of the one or more portions of the carrier wall is provided with one or more impingement apertures therein for passage therethrough of air of a predetermined temperature from a feed source into impingement onto the turbine casing, wherein the carrier wall having the one or more portions provided with the impingement aperture(s) therein is a radially outer one of a pair of carrier walls, each carrier wall extending between front and rear carrier ends, wherein the pair of carrier walls define therebetween one or more chambers for receiving therein heating or cooling air from a feed source via said front end, wherein the radially outer carrier wall having the one or more portions provided with the impingement aperture(s) therein comprises one or more extension sections extending axially, relative to the engine's longitudinal axis, from a main carrier wall section via which the radially outer carrier wall is united with the remainder of the carrier segment, and wherein the or each axial extension section is provided with impingement aperture(s) therein, in addition to the main section.