Gas turbine engine with clutch system between low-pressure compressor and low-pressure turbine
A gas turbine engine having: an engine core having, in serial flow communication, a low-pressure compressor, a high-pressure compressor, a high-pressure turbine drivingly connected to the high-pressure compressor, and a low-pressure turbine drivingly connected to an output shaft; and a clutch having a disengaged configuration in which the low-pressure turbine is drivingly disconnected from the low-pressure compressor such that, in the disengaged configuration, the clutch disengages the low-pressure turbine from the low-pressure compressor, and an engaged configuration in which the low-pressure turbine is drivingly connected to the low-pressure compressor, the low-pressure turbine drivingly connected to the output shaft in both of the engaged and disengaged configurations of the clutch.
1 . A method for a gas turbine engine having a low-pressure compressor, a high-pressure compressor, a high-pressure turbine drivingly engaging the high-pressure compressor, and a low-pressure turbine drivingly connected to an output shaft, the gas turbine engine having an accessory gearbox drivingly engaged to the high-pressure turbine, the method comprising:
receiving a power request;
setting the gas turbine engine in a free-turbine configuration by:
disengaging the low-pressure compressor from the low-pressure turbine with a first clutch configured in a disengaged configuration if the power request is below a power threshold while keeping the low-pressure turbine drivingly connected to the output shaft, and while-keeping the accessory gearbox drivingly engaged to the high-pressure turbine, and
drivingly engaging the low-pressure compressor to the high-pressure compressor with a second clutch configured in an engaged configuration if the power request is below the power threshold;
setting the gas turbine engine in a boosted configuration by engaging the low-pressure compressor to the low-pressure turbine with the first clutch configured in an engaged configuration if the power request is above the power threshold while keeping the low-pressure turbine drivingly connected to the output shaft, and while keeping the accessory gearbox drivingly engaged to the high-pressure turbine.
2 . The method of claim 1 , wherein the gas turbine engine has a low-pressure shaft for drivingly engaging the low-pressure turbine to the low-pressure compressor, the first clutch operatively connected to the low-pressure shaft.
3 . The method of claim 1 , wherein drivingly engaging the low-pressure compressor to the high-pressure compressor includes setting the second clutch in the engaged configuration, the second clutch operatively connected to a high-pressure shaft drivingly engaging the high-pressure compressor to the high-pressure turbine.
4 . The method of claim 1 , wherein setting the gas turbine engine in the free-turbine configuration includes drivingly disengaging the low-pressure compressor from both of the low-pressure turbine and the high-pressure compressor.
5 . The method of claim 1 , comprising selectively setting the gas turbine engine in a single-spool configuration in which the low-pressure compressor, the low-pressure turbine, the high-pressure compressor and the high-pressure turbine are all drivingly connected to one another.
6 . The method of claim 5 , wherein in the single-spool configuration, the low-pressure compressor, the low-pressure turbine, the high-pressure compressor and the high-pressure turbine rotate at the same rotational speed.
7 . The method of claim 1 , wherein the gas turbine engine has a propeller, and wherein setting the gas turbine engine in the free-turbine configuration is done based on the power request and the rotational speed of the propeller.