Inlet cowl deflection limiting strut
A turbofan engine may comprise an inlet and a fan case coupled to the inlet. An engine case may be coupled to the fan case via a vane extending between the fan case and the engine case. A strut apparatus may extend from the fan case and limit deflection of the fan case. The strut apparatus may comprise a first end proximate the fan case, and a second end coupled to at least one of the engine case or a structure for mounting the turbofan engine to an aircraft.
1. A method for controlling a strut coupled to a fan case of a turbofan engine, comprising:
receiving, from a sensor, sensor data usable to predict a temperature of a portion of the turbofan engine;
predicting, by a controller, a current predicted temperature of the portion of the turbofan engine based on the sensor data; and
controlling, by the controller, the strut to at least one of increase or decrease a strut length of the strut based on the current predicted temperature to reduce distortion of a centerline of a core of the turbofan engine.
2. The method of claim 1 , wherein the sensor comprises at least one of a temperature sensor configured to detect a current temperature of the portion of the turbofan engine or another portion of the turbofan engine or a speed sensor configured to detect a current speed of a compressor section or a turbine section of the turbofan engine.
3. The method of claim 1 , wherein controlling the strut to at least one of increase or decrease the strut length includes transmitting a first control signal to a first actuator of the strut to cause the first actuator to at least one of increase or decrease the strut length.
4. The method of claim 3 , wherein controlling the strut to at least one of increase or decrease the strut length further includes:
detecting, by a position sensor of the strut, a current strut length of the strut; and
transmitting a second control signal to the first actuator of the strut to cause the first actuator to at least one of increase or decrease the strut length in response to the current strut length of the strut being different than a desired strut length of the strut.
5. The method of claim 3 , wherein controlling the strut to at least one of increase or decrease the strut length further includes:
detecting, by a position sensor of the strut, a current strut length of the strut; and
transmitting a second control signal to a second actuator of the strut to cause the second actuator to at least one of increase or decrease the strut length in response to the current strut length of the strut being different than a desired strut length of the strut.
6. The method of claim 1 , wherein controlling the strut to at least one of increase or decrease the strut length further includes:
transmitting a first control signal to a first actuator of the strut to cause the first actuator to at least one of increase or decrease the strut length by a first amount; and
transmitting a second control signal to a second actuator of the strut to cause the second actuator to at least one of increase or decrease the strut length by a second amount, the first amount and the second amount each being greater than zero.
7. The method of claim 1 , wherein controlling the strut to at least one of increase or decrease the strut length further includes:
transmitting a first control signal to a first actuator of the strut to cause the first actuator to at least one of increase or decrease the strut length during a first flight of the turbofan engine;
transmitting a second control signal to a second actuator of the strut to cause the second actuator to at least one of increase or decrease the strut length during a subsequent flight of the turbofan engine; and
continuing to alternate between transmitting the first control signal to the first actuator and transmitting the second control signal to the second actuator during future subsequent flights of the turbofan engine.
8. The method of claim 1 , further comprising:
detecting, by a strain gauge, a current load applied to the fan case by the strut;
predicting, by the controller, that the turbofan engine will change from a runway state in which an axis of the turbofan engine is parallel to a ground to a climbing state in which a forward end of the turbofan engine is farther from the ground than an aft end of the turbofan engine; and
controlling the strut to increase the strut length to apply a pre-load to the fan case based on the current load to resist additional distortion of the centerline of the core of the turbofan engine due to an air load applied to an inlet of the turbofan engine in response to predicting that the turbofan engine will change from the runway state to the climbing state.