Thermal barrier coating inside cooling channels

A section for a gas turbine engine comprising:

• an outer gas path wall bounding a radially outward portion of a gas path;
• a plurality of rotor stages each comprising:
• a rotor disk rotatable about an axis;
• an inner gas path wall coupled to and radially outward of the rotor disk, the inner gas path wall bounding a radially inward portion of the gas path;
• a plurality of airfoils extending radially outward from the rotor disk, each of the plurality of airfoils including a platform forming at least a portion of the inner gas path wall;
• a plurality of rotor spokes extending radially between the rotor disk and each platform, the plurality of rotor spokes being circumferentially spaced to define a plurality of cooling channels between the rotor disk and each platform;
• a thermal barrier coating disposed on a surface of at least one of the plurality of cooling channels;
• wherein the plurality of rotor stages includes a first rotor stage and a second rotor stage, the thermal barrier coating extending axially along the plurality of cooling channels between at least the first rotor stage and the second rotor stage;
• and
• wherein the thermal barrier coating is disposed on surfaces of the plurality of cooling channels facing radially inwards and being defined by the first rotor stage and the second rotor stage.

A method of cooling a rotor assembly comprising the steps of:

• providing a rotor disk rotatable about an axis;
• providing a gas path wall coupled to and radially outward of the rotor disk, the gas path wall bounding a gas path;
• providing a plurality of spokes intermediate the rotor disk and the gas path wall, the plurality of rotor spokes being circumferentially spaced such that there is a plurality of cooling channels intermediate the rotor disk and the gas path wall;
• controlling thermal conductivity through the gas path wall into the plurality of cooling channels by using a thermal barrier coating disposed on at least a portion of the plurality of cooling channels;
• and
• wherein surfaces of the plurality of cooling channels facing radially outwards from the axis are free of the thermal barrier coating.