PROCEDE ET DISPOSITIF DE MAINTIEN D'UN JEU CONSTANT ENTRE PARTIES FIXES ET MOBILES D'UNE TURBINE

摘要

A gas turbine engine has a turbine which includes an annular array of rotary aerofoil blades surrounded by an annular shroud member. All or a major portion of the annular shroud member is constituted by a heat pipe. A distance measuring device is provided to measure the clearance between the tips of the rotary aerofoil blades and the shroud member and its output is monitored by a control unit. The control unit is adapted to control a valve which regulates the flow rate of cooling air directed onto the heat pipe. The arrangement is such that the temperature of the heat pipe is maintained at a level which is consistent with the clearance between the rotary aerofoil blade tips and the annular shroud member being within a predetermined range of values.