Methods and apparatus for maintaining rotor assembly tip clearances

A rotor assembly for a gas turbine engine, said assembly comprising:

• at least one case segment comprising an intermediate flange, an aft flange, and a body extending therebetween, said body comprising at least two mounting hooks extending radially inwardly from said body and at least one channel defined between said at least two mounting hooks;
• a plurality of rotor blades;
• at least one turbine shroud assembly coupled radially outward of said plurality of rotor blades such that an axisymmetric running tip clearance is defined between said plurality of rotor blades and said at least one turbine shroud assembly;
• and
• a thermal barrier coating applied to said at least one channel, said coating is configured to facilitate maintaining said axisymmetric running tip clearance during engine operations such that an exhaust gas temperature overshoot and a specific fuel consumption is reduced.

A gas turbine engine comprising:

• a rotor assembly including at least one case segment comprising an intermediate flange, an aft flange, and a body extending therebetween, said body comprising at least two mounting hooks extending radially inwardly from the body and at least one channel defined between said at least two mounting hooks;
• a plurality of rotor blades;
• at least one turbine shroud assembly coupled radially outward of said plurality of rotor blades such that an axisymmetric running tip clearance is defined between said plurality of rotor blades and said at least one turbine shroud assembly;
• and
• a thermal barrier coating applied to said at least one channel, said coating is configured to facilitate maintaining said axisymmetric running tip clearance during engine take-off and cruise operations.