Patent ID: 7322101

Claim:
A method for engineering a gas turbine engine comprising: a rotor stack comprising: a plurality of disks, each disk extending radially from an inner aperture to an outer blade-engaging periphery; and a plurality of spacers, each spacer between an adjacent pair of said disks; and a central shaft carrying the rotor stack and having a tie portion within the rotor stack the tie portion coupled to the disks to transmit a tensile force counter to a longitudinal compression force across the stack, the method comprising: for at least a first condition characterized by a first speed, determining a first longitudinal compression force across the rotor stack; for at least a second condition characterized by a second speed greater than the first speed, determining a second longitudinal compression force across the rotor stack; and modifying at least one of the plurality of spacers so that the second longitudinal compression force exceeds the first longitudinal compression force by a target amount, the method being as a reengineering of an engine configuration from an initial configuration to a reengineered configuration wherein: a disk to disk spacing is increased in the reengineered configuration relative to the initial configuration.