Cmc component with cover plate

A method of controlling cooling air flow within a CMC component, the method comprising:

• providing the CMC component comprising:
• a base having a radial outer surface and a radial inner surface, the base comprising a plurality of ceramic fiber plies and a ceramic matrix, and
• at least one cooling cavity within the base that extends from the outer radial surface of the base into an interior region of the base, the at least one cooling cavity having a cavity opening at the outer radial surface of the base, and the at least one cooling cavity being defined by cavity side walls and a cavity bottom wall, and
• covering the cavity opening of the at least one cooling cavity with a cover plate, the cover plate having one or more cooling air inlets to permit cooling air to flow from a region above the cover plate into the cooling cavity, the cover plate having an outer surface facing the region above the cover plate and an inner surface facing the cavity bottom wall;
• wherein the cover plate further comprises one or more double wall structures extending downward from the inner surface of the cover plate to the cavity bottom wall thereby dividing the cooling cavity into a plurality of cooling subcavities and/or creating a circuitous cooling pathway within the cooling cavity, and wherein a space between the double walls is in fluid communication with a region above the cover plate and the double wall structure is provided with further cooling inlets to allow cooling air to flow though the space between the double walls and into the cooling cavity.

A turbine engine comprising:

• a fan section, a compressor section, a combustion chamber, and a turbine section, the turbine section including at least one rotor and one or more turbine blade(s) extending radially outwardly from the at least one rotor;
• and
• a blade outer air seal assembly positioned between the one or more turbine blade(s) and an outer casing to the engine;
• wherein the blade outer air seal assembly is formed of a plurality blade outer air seal segments, wherein each blade outer air seal segment comprises:
• a ceramic matrix composite substrate having a radial outer surface and a radial inner surface, the substrate comprising a plurality of ceramic fiber plies and a ceramic matrix,
• at least one cooling cavity within the substrate that extends from the outer radial surface of the substrate into an interior region of the substrate, the at least one cooling cavity having a cavity opening at the outer radial surface of the substrate, and the at least one cooling cavity being defined by cavity side walls and a cavity bottom wall, and
• a cover plate covering the cavity opening of the at least one cooling cavity, the cover plate having one or more cooling air inlets to permit cooling air to flow from a region above the cover plate into the cooling cavity, the cover plate having an outer surface facing the region above the cover plate and an inner surface facing the cavity bottom wall;
• wherein the cover plate further comprises one or more double wall structures extending downward from the inner surface of the cover plate to the cavity bottom wall thereby dividing the cooling cavity into a plurality of cooling subcavities and/or creating a circuitous cooling pathway within the cooling cavity, and wherein a space between the double walls is in fluid communication with a region above the cover plate and the double wall structure is provided with further cooling inlets to allow cooling air to flow though the space between the double walls and into the cooling cavity.