Abstract: Methods and systems for determining an engine temperature for a gas turbine engine are provided. An estimated combustor temperature is determined based on at least one operating condition of the gas turbine engine and an estimated vane mass flow. A corrected vane mass flow is determined based on the estimated combustor temperature, the estimated vane mass flow, and a combustor pressure. The corrected vane mass flow is compared to a reference vane mass flow to obtain the mass flow correction factor. When a condition associated with the mass flow correction factor is not satisfied, the estimated combustor temperature is adjusted based on the mass flow correction factor to produce an adjusted combustor temperature; and the mass flow correction factor is updated based on the adjusted combustor temperature. When the condition associated with the mass flow correction factor is satisfied, the estimated combustor temperature is assigned as the engine temperature.

Abstract: A method of determining an inlet total air pressure includes determining a first parameter indicative of a first inlet total air pressure. The method includes executing a sequence that includes: determining a mass air flow passing through the air inlet based on the first parameter, determining a Mach number of air passing through the air inlet based on the mass air flow, determining a static air pressure at the air inlet, determining an air pressure ratio based on the Mach number, generating a subsequent parameter indicative of the revised inlet total air pressure based on the air pressure ratio and the static air pressure, and substituting the subsequent parameter for the first parameter. The method includes executing at least one additional instance of the sequence with the subsequent parameter, and outputting the subsequent parameter as the inlet total air pressure.

Abstract: A method of determining an inlet total air pressure includes determining a first parameter indicative of a first inlet total air pressure. The method includes executing a sequence that includes: determining a mass air flow passing through the air inlet based on the first parameter, determining a Mach number of air passing through the air inlet based on the mass air flow, determining a static air pressure at the air inlet, determining an air pressure ratio based on the Mach number, generating a subsequent parameter indicative of the revised inlet total air pressure based on the air pressure ratio and the static air pressure, and substituting the subsequent parameter for the first parameter. The method includes executing at least one additional instance of the sequence with the subsequent parameter, and outputting the subsequent parameter as the inlet total air pressure.

Abstract: The method can include determining a mass flow rate W of working fluid circulating through the compressor stage, determining a control parameter value associated to the geometrical configuration of the variable geometry element based on the determined value of mass flow rate W; and changing the geometrical configuration of the variable geometry element in accordance with the determined control parameter value.

Abstract: A method of determining an inlet total air pressure includes determining a first parameter indicative of a first inlet total air pressure. The method includes executing a sequence that includes: determining a mass air flow passing through the air inlet based on the first parameter, determining a Mach number of air passing through the air inlet based on the mass air flow, determining a static air pressure at the air inlet, determining an air pressure ratio based on the Mach number, generating a subsequent parameter indicative of the revised inlet total air pressure based on the air pressure ratio and the static air pressure, and substituting the subsequent parameter for the first parameter. The method includes executing at least one additional instance of the sequence with the subsequent parameter, and outputting the subsequent parameter as the inlet total air pressure.

Abstract: The method can include determining a mass flow rate W of working fluid circulating through the compressor stage, determining a control parameter value associated to the geometrical configuration of the variable geometry element based on the determined value of mass flow rate W; and changing the geometrical configuration of the variable geometry element in accordance with the determined control parameter value.

Abstract: Methods and systems for operating an engine are provided. An engine core temperature is monitored. When the engine core temperature is below an engine thermal limit adjusted for a level of deterioration of the engine, an output power of the engine is set in accordance with a reference power based on non-thermal limits of the engine. When the engine core temperature is near or above the engine thermal limit adjusted for the level of deterioration of the engine, the output power of the engine is set to a value lower than the reference power based on non-thermal limits of the engine to reduce the engine core temperature.

Abstract: Methods and systems for determining an engine temperature for a gas turbine engine are provided. An estimated combustor temperature is determined based on at least one operating condition of the gas turbine engine and an estimated vane mass flow. A corrected vane mass flow is determined based on the estimated combustor temperature, the estimated vane mass flow, and a combustor pressure. The corrected vane mass flow is compared to a reference vane mass flow to obtain the mass flow correction factor. When a condition associated with the mass flow correction factor is not satisfied, the estimated combustor temperature is adjusted based on the mass flow correction factor to produce an adjusted combustor temperature; and the mass flow correction factor is updated based on the adjusted combustor temperature. When the condition associated with the mass flow correction factor is satisfied, the estimated combustor temperature is assigned as the engine temperature.

Abstract: Methods and systems for operating an engine are provided. An engine core temperature is monitored. When the engine core temperature is below an engine thermal limit adjusted for a level of deterioration of the engine, an output power of the engine is set in accordance with a reference power based on non-thermal limits of the engine. When the engine core temperature is near or above the engine thermal limit adjusted for the level of deterioration of the engine, the output power of the engine is set to a value lower than the reference power based on non-thermal limits of the engine to reduce the engine core temperature.

Abstract: Methods and systems for determining an engine temperature for a gas turbine engine are provided. An estimated combustor temperature is determined based on at least one operating condition of the gas turbine engine and an estimated vane mass flow. A corrected vane mass flow is determined based on the estimated combustor temperature, the estimated vane mass flow, and a combustor pressure. The corrected vane mass flow is compared to a reference vane mass flow to obtain the mass flow correction factor. When a condition associated with the mass flow correction factor is not satisfied, the estimated combustor temperature is adjusted based on the mass flow correction factor to produce an adjusted combustor temperature; and the mass flow correction factor is updated based on the adjusted combustor temperature. When the condition associated with the mass flow correction factor is satisfied, the estimated combustor temperature is assigned as the engine temperature.

Abstract: Methods and systems for operating an aircraft engine having a compressor are described. The method comprises determining, based on actual operating parameters of the aircraft engine, a compressor mass flow limit for an aerodynamic stability of the aircraft engine; determining an actual compressor mass flow of the compressor of the aircraft engine, wherein the actual compressor mass flow is based on measured values of the aircraft engine; comparing the actual compressor mass flow to the compressor mass flow limit; and governing operation of the aircraft engine to cause an alternative compressor mass flow when the actual compressor mass flow reaches or is anticipated to reach the compressor mass flow limit.

Abstract: The gas turbine engine described includes a first centrifugal compressor, a second centrifugal compressor, and intercompressor pipes extending therebetween. The intercompressor pipes fluidly interconnect an exit of a first impeller of the first centrifugal compressor and an inlet of a second impeller of the second centrifugal compressor. The intercompressor pipes have heat transfer structures on outer surfaces thereof to increase convective heat transfer.

Abstract: Methods and systems for determining an engine temperature for a gas turbine engine are provided. An estimated combustor temperature is determined based on at least one operating condition of the gas turbine engine and an estimated vane mass flow. A corrected vane mass flow is determined based on the estimated combustor temperature, the estimated vane mass flow, and a combustor pressure. The corrected vane mass flow is compared to a reference vane mass flow to obtain the mass flow correction factor. When a condition associated with the mass flow correction factor is not satisfied, the estimated combustor temperature is adjusted based on the mass flow correction factor to produce an adjusted combustor temperature; and the mass flow correction factor is updated based on the adjusted combustor temperature. When the condition associated with the mass flow correction factor is satisfied, the estimated combustor temperature is assigned as the engine temperature.

Abstract: The gas turbine engine described includes a first centrifugal compressor, a second centrifugal compressor, and intercompressor pipes extending therebetween. The intercompressor pipes fluidly interconnect an exit of a first impeller of the first centrifugal compressor and an inlet of a second impeller of the second centrifugal compressor. The intercompressor pipes have heat transfer structures on outer surfaces thereof to increase convective heat transfer.

Abstract: The present invention relates to a device for specific inhalation challenges, especially bronchical provocation tests, including a compressed air supply, a particle generator an exposure room, an orofacial mask, a gas-aerosol photometer, a manometer, a valve and a suction pump. The invention also relates to a method of using the device and to an improved particle generator.

Abstract: An improved sampling device for collecting at least part of air-borne particles in a workman's breathing zone. The device comprises a cassette provided with an inlet, an outlet and an air filter, a vacuum pump and a flexible tubing of determined length connecting the vacuum pump to the outlet of the cassette. In use, a portion of the air contained in the breathing zone of the workman is drawn through the filter and the particles collected thereon. This device is improved in that a deformable metallic tubing is positioned inside a portion of the flexible tubing or is positioned between a short length of a tubing connected to the outlet of the cassette and this flexible tubing. In addition, at least one fastener is provided for fixing the deformable metallic tubing and eventually the flexible tubing, to at least one strap intended to be tightened around a workman's head. This device is useful to position the air-intake of the cassette in the workman's breathing zone.