System and method for reducing a clearance gap in an engine
A method for reducing a clearance gap between a plurality of rotor blades and a shroud assembly of an engine includes determining, with a flight control system, that an airplane is in a first flight condition. The method also includes adjusting the clearance gap to a first clearance gap distance associated with the first flight condition. Further, the method includes receiving, with the flight control system, a demand for a second flight condition. During the second flight condition, the method includes adjusting at least two independently controllable parameters, the at least two independently controllable parameters comprising, at least, a first parameter for optimizing the clearance gap and a second parameter for satisfying a thrust demand of the engine, the first parameter having a first impact on the clearance gap, the second parameter having a second impact on the clearance gap, the first impact being greater than the second impact.
1. A method for reducing a clearance gap between a plurality of rotor blades and a shroud assembly of an engine, the method comprising:
determining, with a flight control system, that an airplane is in a first flight condition;
adjusting the clearance gap to a first clearance gap distance associated with the first flight condition;
receiving, with the flight control system, a demand for a second flight condition; and
during the second flight condition, adjusting at least two independently controllable parameters, the at least two independently controllable parameters comprising, at least, a first parameter for optimizing the clearance gap and a second parameter for satisfying a thrust demand of the engine, the first parameter having a first impact on the clearance gap, the second parameter having a second impact on the clearance gap, the first impact being greater than the second impact, wherein a net thrust response to the second flight condition is essentially zero.
2. The method of claim 1 , wherein the at least two independently controllable parameters comprise a power parameter of the engine and a pitch parameter of the engine.
3. The method of claim 2 , wherein the power parameter comprises at least one of fan speed, engine pressure ratio, or cooling flow and the pitch parameter comprises a fan pitch.
4. The method of claim 3 , further comprising maintaining the fan pitch below aeromechanic and operability limits.
5. The method of claim 1 , wherein the first flight condition is a steady-state cruise condition.
6. The method of claim 1 , wherein the second flight condition is an increased power transient.
7. The method of claim 1 , wherein the engine comprises at least one of a hybrid electric engine, an electric engine, or a fuel-burning engine.
8. A system for reducing a clearance gap between a plurality of rotor blades and a shroud assembly of an engine, the system comprising:
a flight control system comprising a memory and one or more processors configured to perform a plurality of operations, the plurality of operations comprising:
determining that an airplane is in a first flight condition;
adjusting the clearance gap to a first clearance gap distance associated with the first flight condition;
receiving a demand for a second flight condition; and
during the second flight condition, adjusting at least two independently controllable parameters, the at least two independently controllable parameters comprising, at least, a first parameter for optimizing the clearance gap and a second parameter for satisfying a thrust demand of the engine, the first parameter having a first impact on the clearance gap, the second parameter having a second impact on the clearance gap, the first impact being greater than the second impact, wherein a net thrust response to the second flight condition is essentially zero.
9. The system of claim 8 , wherein the at least two independently controllable parameters comprise a power parameter of the engine and a pitch parameter of the engine.
10. The system of claim 9 , wherein the power parameter comprises at least one of fan speed, engine pressure ratio, or cooling flow and the pitch parameter comprises a fan pitch.
11. The system of claim 10 , wherein the plurality of operations further comprise maintaining the fan pitch below aeromechanic and operability limits.
12. The system of claim 8 , wherein the first flight condition is a steady-state cruise condition.
13. The system of claim 8 , wherein the second flight condition is an increased power transient.
14. The system of claim 8 , wherein the engine comprises at least one of a hybrid electric engine, an electric engine, or a fuel-burning engine.
15. A method for controlling a clearance gap between a plurality of rotor blades and a shroud assembly of an aircraft engine, the method comprising:
receiving, with a flight control system, a request from an aircraft operator to institute a step climb of the aircraft engine to a higher altitude; and
increasing an engine speed of the aircraft engine to effectuate the step climb while also adjusting a power parameter of the aircraft engine to optimize the clearance gap and adjusting a fan pitch of the aircraft engine to satisfy a thrust demand of the aircraft engine, wherein adjusting the fan pitch includes implementing a first pitch response for a first portion of the step climb and subsequently implementing a second pitch response for a second portion of the step climb in which the fan pitch is increased up to aeromechanical and operability limits.
16. The method of claim 15 , wherein the power parameter comprises at least one of fan speed, engine pressure ratio, or cooling flow.
17. The method of claim 15 , further comprising independently controlling the power parameter and the fan pitch.
18. The method of claim 15 , further comprising maintaining the fan pitch below the aeromechanic and operability limits.
19. The method of claim 15 , wherein the aircraft engine comprises at least one of a hybrid electric engine, an electric engine, or a fuel-burning engine.