US 11,668,252 B2
Method for controlling a clearance control valve during a step-climb in cruise phase
Jacques Auriol, Moissy-Cramayel (FR)
Assigned to SAFRAN AIRCRAFT ENGINES, Paris (FR)
Filed by SAFRAN AIRCRAFT ENGINES, Paris (FR)
Filed on Jul. 16, 2020, as Appl. No. 16/930,812.
Claims priority of application No. 19 08226 (FR), filed on Jul. 19, 2019.
Prior Publication US 2021/0017913 A1, Jan. 21, 2021
Int. Cl. F02C 9/22 (2006.01); F01D 11/24 (2006.01)
CPC F02C 9/22 (2013.01) [F01D 11/24 (2013.01); F05D 2220/323 (2013.01); F05D 2270/02 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A method for controlling a clearance control valve of a turbomachine comprising:
during a maneuver to increase an engine speed in cruise phase, actuating a command to reduce an opening of the clearance control valve by a Full Authority Digital Engine Control based on a change in a state of a step-climb signal provided by a flight management system in order to increase clearances at tips of the turbomachine blades,
wherein when the maneuver to increase the engine speed is followed by a slow action or no action at all of a pilot, an increase in the opening of the clearance control valve follows its reduction, at an expiry of either of the following two time limits: a first time limit starting at the change in the state of the step-climb signal and determined not to penalize performance of the engine for too long and a second time limit starting at an end of said maneuver and determined as a function of a thermal time constant of a casing.