A self-adapting gas turbine firebox with variable geometry includes at least one system with variable opening for automatically adjusting a combustion configuration inside a combustion chamber according to an air temperature, particularly of air from a compressor. The adjustment is performed by a thermosensitive member that controls at least one cross-sectional area of a passage to the combustion chamber, for air which participates in the combustion of fuel or participates in a dilution of gases effective inside the combustion chamber.

The invention concerns an aircraft propulsion control system in which a gas turbine engine has an actuable flow opening for control of flow to or from a portion of the engine. One or more sensor is arranged to sense a condition indicative of vapor trail formation by the exhaust flow from the engine. A controller is arranged to control actuation of the flow opening so as to reduce the efficiency of the engine upon sensing of said condition by the one or more sensor. In one example, the flow opening is a variable area fan nozzle.

An aspect includes a system for a gas turbine engine. The system includes one or more bleeds of the gas turbine engine and a control system configured to check one or more activation conditions of a dirt rejection mode in the gas turbine engine. A bleed control schedule of the gas turbine engine is adjusted to extend a time to hold the one or more bleeds of the gas turbine engine partially open at a power setting above a threshold based on the one or more activation conditions. One or more deactivation conditions of the dirt rejection mode in the gas turbine engine are checked. The dirt rejection mode is deactivated to fully close the one or more bleeds based on the one or more deactivation conditions.

A valve includes an inlet, an outlet, and a biasing element. The biasing element includes a first spring element, a second spring element, and a valve element. The second spring element includes at least one bimetallic disk including a first and second material. The first material includes a first coefficient of linear thermal expansion, and the second material includes a second coefficient of linear thermal expansion different than the first coefficient of linear thermal expansion. The valve element disposed on an end of the first spring element.

A system includes an engine configured to generate power to drive a load. The system also includes a power augmentation system configured to augment a power output of the engine when the power augmentation system is activated. Additionally, the system includes a controller operatively coupled to the power augmentation system. The controller is configured to estimate a potential change in the power output of the engine caused by activation of the power augmentation system using a power augmentation model and an engine performance model.

An aircraft including lean-burn gas turbine engines operating in pilot-plus-mains mode with a given initial fuel flow W.sub.0, a method of controlling the optical depth of contrails produced by a first group of engines includes the steps of (i) reducing fuel flow to each engine in the first group to change the operation of each engine from pilot-plus-mains mode to pilot-only mode, and (ii) adjusting fuel flow to one or more engines in a second group of engines such that the total fuel flow to engines of the second group is increased, all engines of the second group remaining in pilot-plus-mains mode, and wherein the set of lean-burn engines consists of the first and second groups. Depending on atmospheric conditions, the average optical depth of contrails produced by the engines may be enhanced or reduced compared to when all engines operate in pilot-plus-mains mode with a fuel flow W.sub.0.

A system includes a temperature control system configured to couple to an air intake section of a gas turbine system. The temperature control system includes a variable heating system having one or more heaters configured to heat an airflow in the air intake section when the airflow is cooled by an evaporative cooling system. The temperature control system is configured to control the variable heating system to vary an amount of heat supplied by the one or more heaters based on at least one temperature measurement relative to a temperature threshold.

A system and method for predicting a remaining oil life of oil in a gearbox of an air turbine starter of a vehicle. The method includes generating a temperature data, generating an environmental data set by an environmental sensor, predicting a remaining oil life based on the temperature data set and the environmental data set and scheduling a maintenance event in response to the prediction of the remaining oil life.

A gas turbine includes a compressor configured to compress air; a combustor configured to mix and combust fuel and compressed air compressed by the compressor; a turbine configured to obtain rotational power using combustion gas generated by the combustor; an inlet guide vane disposed at an intake of the compressor to adjust a flow rate of air flowing into the compressor; a bleed line configured to return a part of the compressed air pressurized in the compressor to the intake of the compressor; and an on-off valve disposed in the bleed line. When the output of the gas turbine increases, a preset maximum value limit of the inlet guide vane is corrected based on a valve opening degree command value of the on-off valve and a compressor intake temperature such that the gas turbine achieves a predetermined performance.

A method for starting a turbine engine in cold weather, including a starting system intended for rotating a drive shaft of the turbine engine. The method includes the following steps: a pre-starting step in which a first starting signal is generated to control the drive shaft in a first direction of rotation about a longitudinal axis and in a second opposite direction of rotation in an alternating manner; and a starting step in which a second starting signal is transmitted to the starting system in order for the latter to drive the drive shaft of the turbine engine in a normal direction of rotation and in which the drive shaft is rotated until a rotation speed that causes the turbine engine to start.