Abstract: A cooling device for a stationary ring surrounding a gas-turbine hot-gas flow path, said ring being made up of a plurality of ring segments that are fastened by upstream and downstream fastener systems onto a plurality of spacer segments forming a support spacer surrounding said ring so as to co-operate therewith to define at least one annular impact cavity into which at least one air supply orifice opens out, each ring segment having walls that are pierced with a plurality of air exhaust holes opening out both into the impact cavity, and into the hot-gas flow path, the device further comprising means for channeling the air coming from leakage through the seals of the fastener systems, and for directing it towards at least one of the axial ends of the ring segments so as to cool said end(s).

Abstract: A system for controlling a flow of air applied to a gas turbine shroud in an airplane engine, the air flow being adjusted by a regulator valve of position that is controlled by a first control signal calculated on the basis of a first setpoint value corresponding to predetermined clearance between the rotor and the turbine shroud. The system further comprises means for calculating at least one second control signal based on a second setpoint value different from the first value representative of clearance in the turbine, and selector means for-selecting the second control signal to control the regulator valve in response to one or more engine parameters. With such a system, it is possible to control the air flow applied to the shroud in application of a plurality of control logic systems.

Abstract: A device for axially holding a ring spacer sector of a high-pressure turbine of a turbomachine, said spacer sector comprising an upstream radial wall provided with an outer upstream tongue for being engaged in a corresponding upstream groove of a casing of the turbine, and with an inner upstream tongue for being engaged in a corresponding upstream groove of a ring sector, said device comprising a piece of longitudinally-extending sheet metal that constitutes a heat shield disposed upstream from the upstream radial wall of the spacer sector against an inner surface of the casing, the piece of longitudinally-extending sheet metal bearing axially against the upstream radial wall of the spacer sector and being secured to the casing so as to hold the spacer sector axially.

Abstract: A device for tuning clearance at rotor blade tips in a gas turbine rotor, the device comprising at least one annular air flow duct that is mounted around the circumference of an annular casing of a stator of the turbine, the annular air flow duct being designed to discharge air onto the casing in order to modify the temperature thereof. A tubular air manifold is disposed around the air flow duct(s). There are also disposed an air feed tube to supply the tubular air manifold with air and an air pipe opening in the tubular air manifold and opening out into the air flow duct(s). The air pipe is provided with a balancing diaphragm for balancing the air flowing through the pipe.

Abstract: A device for tuning clearance at rotor blade tips in a gas turbine rotor, the device comprising at least one annular air flow duct that is mounted around the circumference of an annular casing of a stator of the turbine, the annular air flow duct being designed to discharge air onto the casing in order to modify the temperature thereof. A tubular air manifold is disposed around the air flow duct(s). There are also disposed an air feed tube to supply the tubular air manifold with air and an air pipe opening in the tubular air manifold and opening out into the air flow duct(s). The air pipe is provided with a balancing diaphragm for balancing the air flowing through the pipe.

Abstract: A clearance control device for controlling clearance between rotary blade tips and a stationary bushing of a gas turbine having a casing that is provided with at least two annular ridges, the clearance control device including a circular tuning unit that includes air circulation means for circulating air, said means being made up of at least three ducts; air supply means for supplying air to the air flow ducts; and air discharge means for discharging air on the ridges in order to modify the temperature, the air discharge means for each duct being made up of at least one top row having a number N of perforations disposed facing one of the side faces of the ridges and of at least one bottom row having a number 2N of perforations disposed facing a connection radius that connects the ridges to the casing.

Abstract: A system for controlling a flow of air applied to a gas turbine shroud in an airplane engine, the air flow being adjusted by a regulator valve of position that is controlled by a first control signal calculated on the basis of a first setpoint value corresponding to predetermined clearance between the rotor and the turbine shroud. The system further comprises means for calculating at least one second control signal based on a second setpoint value different from the first value representative of clearance in the turbine, and selector means for-selecting the second control signal to control the regulator valve in response to one or more engine parameters. With such a system, it is possible to control the air flow applied to the shroud in application of a plurality of control logic systems.

Abstract: A cooling device for a stationary ring surrounding a gas-turbine hot-gas flow path, said ring being made up of a plurality of ring segments that are fastened by upstream and downstream fastener systems onto a plurality of spacer segments forming a support spacer surrounding said ring so as to co-operate therewith to define at least one annular impact cavity into which at least one air supply orifice opens out, each ring segment having walls that are pierced with a plurality of air exhaust holes opening out both into the impact cavity, and into the hot-gas flow path, the device further comprising means for channeling the air coming from leakage through the seals of the fastener systems, and for directing it towards at least one of the axial ends of the ring segments so as to cool said end(s).

Abstract: A device for axially holding a ring spacer sector of a high-pressure turbine of a turbomachine, said spacer sector comprising an upstream radial wall provided with an outer upstream tongue for being engaged in a corresponding upstream groove of a casing of the turbine, and with an inner upstream tongue for being engaged in a corresponding upstream groove of a ring sector, said device comprising a piece of longitudinally-extending sheet metal that constitutes a heat shield disposed upstream from the upstream radial wall of the spacer sector against an inner surface of the casing, the piece of longitudinally-extending sheet metal bearing axially against the upstream radial wall of the spacer sector and being secured to the casing so as to hold the spacer sector axially.

Abstract: A clearance control device for controlling clearance between rotary blade tips and a stationary bushing of a gas turbine having a casing that is provided with at least two annular ridges, the clearance control device including a circular tuning unit that includes air circulation means for circulating air, said means being made up of at least three ducts; air supply means for supplying air to the air flow ducts; and air discharge means for discharging air on the ridges in order to modify the temperature, the air discharge means for each duct being made up of at least one top row having a number N of perforations disposed facing one of the side faces of the ridges and of at least one bottom row having a number 2N of perforations disposed facing a connection radius that connects the ridges to the casing.

Abstract: A measurement method of measuring the unsteady flow of velocity of a fluid, characterized by the fact that it comprises the following steps: i) detecting instants at which the acceleration of the fluid is zero; ii) defining a measurement of the fluid velocity at instants where the acceleration is zero; and iii) determining changes in velocity between instants of zero acceleration by numerically integrating the difference between two static pressures.