초록 ▼

A method and an apparatus for determining the clearance between the rotor blades of a rotor assembly and a shroud disposed radially outside of the rotor assembly is provided that calculates steady-state operating conditions for a given power engine setting and utilizes those steady-state conditions

A method and an apparatus for determining the clearance between the rotor blades of a rotor assembly and a shroud disposed radially outside of the rotor assembly is provided that calculates steady-state operating conditions for a given power engine setting and utilizes those steady-state conditions to determine a steady-state clearance at the given power setting. The method and apparatus further calculate instantaneous thermal conditions for the rotor disk, rotor blades, and shroud. The instantaneous thermal conditions are subsequently used to determine the amount of instantaneous thermal expansion of the rotor disk, rotor blades, and shroud. A clearance transient overshoot is determined using the calculated instantaneous thermal expansions. The actual clearance is determined using the steady-state clearance and the clearance transient overshoot.

대표청구항 ▼

[ What is claimed is:] [1.]1. A method for determining the clearance between the rotor blades of a rotor assembly and a shroud disposed radially outside the rotor assembly within a gas turbine engine, wherein the rotor blades of the rotor assembly are attached to a rotor disk, said method comprising

[ What is claimed is:] [1.]1. A method for determining the clearance between the rotor blades of a rotor assembly and a shroud disposed radially outside the rotor assembly within a gas turbine engine, wherein the rotor blades of the rotor assembly are attached to a rotor disk, said method comprising the steps of:determine one or more steady-state operating conditions for a given steady-state power setting using a given temperature value, a given altitude value, and a given mach number value;determine a steady-state clearance value for a predetermined power rating of the engine using said one or more steady-state operating conditions;determine an instantaneous thermal condition (T.sub.R) for the rotor disk, an instantaneous thermal condition (T.sub.B) for the rotor blades, and an instantaneous thermal condition (T.sub.S) for the shroud;determine a value (GAIN.sub.R) representative of the thermal expansion of the rotor disk, a value (GAIN.sub.B) representative of the thermal expansion of the rotor blades, a value (GAIN.sub.S) representative of the thermal expansion of the shroud, using said instantaneous thermal conditions;determine an instantaneous clearance transient overshoot value (CTO) using said values representative of the thermal expansion of the rotor disk, rotor blades, and shroud;determine a clearance value using said steady-state clearance value and said instantaneous clearance transient overshoot value.