A vertical-cavity surface-emitting laser device including a lower mirror, an upper mirror disposed over the lower mirror, an active region disposed between the lower mirror and the upper mirror, a lower n-type cladding layer disposed between the active region and the lower mirror, an upper n-type cladding layer disposed between the active region and the upper mirror, a heavily doped p-type semiconductor layer disposed between the active region and the upper n-type cladding layer, and a heavily doped n-type semiconductor layer disposed between the heavily doped p-type semiconductor layer and the upper n-type cladding layer to form a tunnel junction with the heavily doped p-type semiconductor layer.

The invention relates to a method for measuring the flow rate of cooling air in a cooling air circuit (13) of a casing (121) of a high-pressure turbine (9) of a turbomachine (1). The invention is characterised in that sensors (21, 22, 24, 26, 28) are used to measure a total pressure at the fan inlet, a static pressure at the outlet of the high-pressure compressor (6), a rotational speed of the low-pressure shaft (101), a rotational speed of the high-pressure shaft (91) and a degree of valve opening of the cooling air circuit (13), a calculation unit is used to calculate the flow rate of cooling air on the basis of at least the measurement of these.

A gas turbine engine has a fan and a compressor section with a first lower pressure location and a second higher pressure location. A heat exchanger and a higher pressure tap from the second higher pressure location pass through the heat exchanger. Air in the higher pressure tap is cooled by air from a lower pressure tap from the first lower pressure location. A valve controls flow to the heat exchanger from the lower pressure tap, the valve being controlled to limit flow from the lower pressure tap under certain conditions.

A set of gas turbine engine components comprises N gas turbine engine components. Each gas turbine engine component has a respective flow value. A method for selecting the N gas turbine engine components includes ordering the gas turbine engine components in dependence upon their respective flow value. For each ordered group of components a maximum range is determined for the respective flow values. If this maximum range is less than a pre-determined range limit then the ordered group becomes a set. If this criteria is not met then another component is added to the group, the group is reordered by flow value and the range check is repeated with allowable groups forming selected sets and further components being added as required.

Vanes for use in gas turbine engines and methods of measuring cooling air flow through vanes are disclosed herein. Each vane includes an airfoil and an end wall. The airfoil is shaped to interact with hot gasses moving along a primary gas path during operation of the gas turbine engine. The end wall is coupled to the airfoil and shaped to define a boundary of the primary gas path near a radial end of the airfoil. The end wall includes a platform that is exposed to the primary gas path and a projection that extends away from the platform and is located outside the primary gas path.

The invention relates to a lubrication device for a turbine engine, comprising an oil intake pipe (23) provided with a pump (24) for supplying oil and control means (25) located downstream from the supply pump (24), a supply pipe (26) intended for supplying oil to a member to be lubricated and a recirculation pipe (27), the control means (25) making it possible to direct all or part of the flow of oil from the intake pipe (23) towards the supply pipe (26) and/or towards the recirculation pipe (27), the pump (24) being driven by at least one rotary member of an accessory gearbox of the turbine engine.

A gas turbine engine that includes an inlet volume flow control appliance and methods of operating the same are provided. The method includes operating the gas turbine engine with the inlet volume flow control appliance supplying a compressor inlet volume flow that is below a maximum compressor inlet volume flow. A mass flow of a liquid agent is added to a compressor gas mass flow while the gas turbine engine is operated with a compressor inlet volume flow below a maximum compressor inlet volume flow. The mass flow of a liquid agent may be controlled as a function of the pitch of variable inlet guide vanes. The method further comprises adjusting the volume flow control appliance to increase the compressor inlet volume flow and increasing the mass flow of liquid agent added to the compressor gas mass flow while the inlet volume flow control appliance increases the compressor inlet volume.

A gas turbine cooling system includes: a cooling air line that guides compressed air; a cooler that cools the compressed air; a flow rate adjuster that adjusts the flow rate of the cooling air; and a control device. The control device includes: a load change determination unit that determines whether a load indicated by a load command of the gas turbine has changed; a first command generation section that generates a first command indicating such an operation amount of the flow rate adjuster as allows the flow rate of the cooling air to meet a target flow rate; and a second command generation section that, when it is determined that the load indicated by the load command has changed, generates a second command indicating such an operation amount of the flow rate adjuster as allows a change-adapted flow rate higher than the target flow rate to be met.

Systems and methods for controlling tip clearance in a gas turbine engine are provided. The system may include a distribution manifold positioned along the engine case for a turbine of a gas turbine engine. The distribution manifold may include a passageway for a thermal fluid, an inlet configured to direct the thermal fluid into the passageway, an inner surface extending along and facing the outer surface of the engine case, and a plurality of outlets configured to direct the thermal fluid onto the outer surface of the engine case. The thermal fluid may include bypass air. A component may add kinetic energy to the thermal fluid.

A gas turbine engine includes a turbine and a turbine cooling arrangement. The turbine includes a turbine rotor surrounded by a static rotor track liner, and a nozzle guide vane downstream of the rotor in a core main gas flow path. The cooling arrangement includes a first air duct that provides cooling airflow to a rotor track liner cooling plenum and a second air duct that provides a cooling airflow to the nozzle guide vane. A common manifold is upstream in the cooling airflow of the ducts and provides cooling air to the ducts. A two-way valve modulates air provided to the ducts from the manifold. The valve is operates in a first or second mode. In the first mode, air flow to the first duct is relatively high and airflow to the second duct is relatively low compared to where the valve is operated in the second mode.