Method and System for Mitigating Bowed Rotor Operation of Gas Turbine Engine

A gas turbine engine, comprising:

• a rotor assembly comprising a driveshaft;
• and
• an energy storage device selectively coupled to the rotor assembly via a clutch mechanism,
• wherein the clutch mechanism engages the energy storage device to couple the rotor assembly to the energy storage device when the rotor assembly rotates to a lower speed limit defined below an idle speed condition, and
• wherein the clutch mechanism disengages the energy storage device to decouple the rotor assembly from the energy storage device when the rotor assembly rotates to an upper speed limit defined at or below the idle speed condition.

A gas turbine engine, comprising:

• a rotor assembly comprising a driveshaft;
• and
• an energy storage device selectively coupled to the rotor assembly via a clutch mechanism,
• wherein the rotor assembly is configured to rotate while defining a bowed rotor condition from approximately zero revolutions per minute (RPM) to within a bowed rotor mitigation speed range,
• wherein the bowed rotor mitigation speed range is defined by a lower speed limit greater than zero RPM and an upper speed limit less than or equal to an idle speed condition of the gas turbine engine,
• wherein the clutch mechanism is configured to couple the rotor assembly to the energy storage device such that a load is applied to the rotor assembly via the energy storage device,
• wherein the gas turbine engine is configured adjust the load to limit rotational speed or acceleration of the rotor assembly to within the bowed rotor mitigation speed range for a period of time;
• and
• wherein the clutch mechanism is configured to decouple the rotor assembly from the energy storage device to remove the load to enable rotation of the rotor assembly to the idle speed condition following the period of time.