Turbine engine and method of cooling

A turbine engine comprising:

• a starter motor;
• and
• a full authority digital engine control (FADEC) system coupled in communication with said starter motor, said FADEC system configured to perform a method of shutting down and cooling a turbine engine, the method comprising:
• shutting off a flow of fuel to a combustor assembly of a turbine engine in response to a full stop command such that a rotational speed of the turbine engine decreases;
• obtaining feedback indicating a likelihood that residual heat is present in the turbine engine sufficient to cause a thermal gradient capable of forming thermal rotor bow, wherein the feedback comprises a running time of the turbine engine being greater than a predetermined time threshold;
• determining a flight status of an aircraft attached to the turbine engine, ensuring no response to the feedback if the aircraft is in flight;
• if the aircraft is not in flight, then, responsive to the feedback, actuating said starter motor using a flow of air from an auxiliary power unit, either as the rotational speed of the turbine engine decreases or at a preset time after the turbine engine receives the full stop command, the actuated starter motor to motor the turbine engine;
• determining a resonant rotational speed of the turbine engine based on a vibratory response;
• and
• continuously or intermittently rotating a rotor assembly of the turbine engine at a rotor speed that is less than the resonant rotational speed, using a drive shaft coupled to said actuated starter motor to motor the turbine engine such that residual heat is exhausted from the turbine engine;
• wherein an amount of time for the actuated starter motor to motor the turbine engine is based on the vibratory response.

A non-transitory computer-readable medium having computer-executable instructions embodied thereon for use in operating a turbine engine, wherein, when executed by at least one processor, the computer-executable instructions cause the processor to perform a method of shutting down and cooling a turbine engine, the method comprising:

• shutting off a flow of fuel to a combustor assembly of a turbine engine in response to a full stop command such that a rotational speed of the turbine engine decreases;
• obtaining feedback indicating a likelihood that residual heat is present in the turbine engine sufficient to cause a thermal gradient capable of forming thermal rotor bow, wherein the feedback comprises a running time of the turbine engine being greater than a predetermined time threshold;
• determining a flight status of an aircraft attached to the turbine engine, ensuring no response to the feedback if the aircraft is in flight;
• if the aircraft is not in flight, then, responsive to the feedback, actuating a starter motor of the turbine engine using a flow of air from an auxiliary power unit, either as the rotational speed of the turbine engine decreases or at a preset time after the turbine engine receives the full stop command, the actuated starter motor to motor the turbine engine;
• determining a resonant rotational speed of the turbine engine based on a vibratory response;
• and
• continuously or intermittently rotating a rotor assembly of the turbine engine at a rotor speed that is less than the resonant rotational speed, using a drive shaft coupled to said actuated starter motor to motor the turbine engine such that residual heat is exhausted from the turbine engine;
• wherein an amount of time for the actuated starter motor to motor the turbine engine is based on the vibratory response.