Abstract: A gas turbine engine includes an annular plenum defined with an outer skin and a perforated inner skin for receiving selective air flow to impinge a support case which supports shrouds of the rotor assemblies of the engine therein for active tip clearance control of the rotor assemblies. In one embodiment a bobbin-type transfer tube for supplying cooling air into the plenum, is provided between an outer case of the engine an the plenum such that the thermally induced relative movement of the outer case and the plenum is permitted.

Abstract: A method of cooling a shroud ring in a turbine section of gas turbine engine includes identifying a series of alternating high temperature regions and lower temperature regions of a circumferential temperature distribution about the inner surface of the shroud ring, and impinging cooling air on to an outer surface of the shroud ring. More cooling air is impinged onto regions which correspond to the high temperature regions on the shroud ring than to regions corresponding to the lower temperature regions of the shroud ring.

Abstract: A method of cooling a shroud ring in a turbine section of gas turbine engine includes identifying a series of alternating high temperature regions and lower temperature regions of a circumferential temperature distribution about the inner surface of the shroud ring, and impinging cooling air on to an outer surface of the shroud ring. More cooling air is impinged onto regions which correspond to the high temperature regions on the shroud ring than to regions corresponding to the lower temperature regions of the shroud ring.

Abstract: A cooled turbine shroud segment for a gas turbine engine, having an axially extending shroud ring segment with an inner surface, an outer surface, an upstream flange and a downstream flange. The flanges mount the shroud ring within an engine casing. A perforated cooling air impingement plate is disposed on the outer surface of the shroud ring between the upstream flange and the downstream flange, with an impingement plenum defined between the impingement plate and the outer surface. Axially extending cooling bores in the ring segment extend between the impingement plenum and an outlet. A trough adjacent the outlet directs cooling air from the outlet towards a downstream stator vane to cool the stator vane.

Abstract: A cooled turbine shroud segment for a gas turbine engine, having an axially extending shroud ring segment with an inner surface, an outer surface, an upstream flange and a downstream flange. The flanges mount the shroud ring within an engine casing. A perforated cooling air impingement plate is disposed on the outer surface of the shroud ring between the upstream flange and the downstream flange, with an impingement plenum defined between the impingement plate and the outer surface. Axially extending cooling bores in the ring segment extend between the impingement plenum and an outlet. A trough adjacent the outlet directs cooling air from the outlet towards a downstream stator vane to cool the stator vane.