Abstract: A turbine ring assembly includes a ring support structure and a plurality of ring sectors, each including a single piece of ceramic matrix composite material. Each ring sector includes a first portion forming an annular base with an inside face defining an inside face of the turbine ring and an outside face from which there extends two tab-forming portions including ends that are engaged in housings in the ring support structure. The ring sectors present a section that is substantially ?-shaped and the ends of the tabs are held without radial clearance by the ring support structure. The tabs can have a free length in meridian section that is not less than three times their mean width.

Abstract: A system and method for controlling clearance between tips of moving blades of an aeroplane gas-turbine engine and a turbine shroud of an outer casing surrounding the blades. The method includes controlling, according to an operating speed of the engine, a valve positioned in an air duct opening at a stage of the compressor of the engine and leading into a control housing positioned around the outer surface of the turbine shroud and supplied with air coming only from the compressor stage. The valve is opened to cool the turbine shroud during a high-speed phase corresponding to takeoff and climb phases of an aeroplane propelled by the engine and during a nominal-speed phase following the high-speed phase and corresponding to a cruise phase of the aeroplane.

Abstract: A turbine ring assembly includes a ring support structure and a plurality of ring sectors, each including a single piece of ceramic matrix composite material. Each ring sector includes a first portion forming an annular base with an inside face defining an inside face of the turbine ring and an outside face from which there extends two tab-forming portions including ends that are engaged in housings in the ring support structure. The ring sectors present a section that is substantially ?-shaped and the ends of the tabs are held without radial clearance by the ring support structure. The tabs can have a free length in meridian section that is not less than three times their mean width.

Abstract: The turbine casing includes a circumferential wall coaxially surrounding a ring that surrounds the moving blades of the turbine. The casing includes a plurality of perforations delivering air for ventilating the outside face of the circumferential wall in uniform manner.