Patent attributes
A clearance control device for controlling clearance between rotary blade tips and a stationary bushing of a gas turbine having a casing that is provided with at least two annular ridges, the clearance control device including a circular tuning unit that includes air circulation means for circulating air, said means being made up of at least three ducts; air supply means for supplying air to the air flow ducts; and air discharge means for discharging air on the ridges in order to modify the temperature, the air discharge means for each duct being made up of at least one top row having a number N of perforations disposed facing one of the side faces of the ridges and of at least one bottom row having a number 2N of perforations disposed facing a connection radius that connects the ridges to the casing.