Blade assembly

An airfoil shaped blade assembly suitable for attachment to a turbine rotor hub, the blade assembly including a structurally supportive metallic core having inner and outer surfaces, a ceramic blade jacket fitted over the metallic core, each having a leading edge and trailing edge, a base element including means for affixing the base element to the turbine rotor hub, and a blade cap;

• the improvement comprising:
• a thin coolant liner including inner and outer surfaces, the liner positioned intermediate the blade metallic core and ceramic jacket;
• multiple and variably spaced ridges formed on the thin liner inner surface in contact with the metallic core outer surface;
• variable-size multiple cooling passages formed between the thin liner inner surface and metallic core outer surface by the multiple spaced ridges in contact with the metallic core outer surface;
• a circumferential stagnant air gap formed between the thin liner and the ceramic blade jacket, the air gap communicating with a pressure equalizing vent in the assembly base element;
• positioning tabs affixed to the outer surface of the liner at the top thereof, two of which are positioned at a leading edge pressure side and at least one positioned at a trailing edge pressure side, all in contact with the ceramic jacket inner surface adjacent the blade assembly cap;
• a friction reducing washer located intermediate the cap and the top of the assembly ceramic blade jacket to protect the ceramic blade jacket against compression loads;
• and
• a compressible compliant material wave flexure located intermediate the base of the ceramic jacket and the base element to seal the stagnant air gap during assembly operation.