Patent attributes
A composite turbine blade for use in a gas turbine engine under high gas flow temperature. The blade includes a root and platform portion formed out of the standard high temperature resistant metallic material of the prior art blades and with a near wall cooled metallic spar extending along the suction side wall of the blade and wrapping around the leading edge and the trailing edge portions of the blade. The wrap around spar forms a concave opening in which a ceramic or carbon fiber mid chord section of the blade is secured to form the composite blade. The solid ceramic or carbon fiber mid-chord blade is exposed to the pressure side hot gas flow and requires no cooling. Radial cooling channels with pin fins extend along the blade spar on the leading and trailing edges and on the suction side wall to provide cooling for the metallic portions of the composite blade. Spanwise attachment hooks extend out from the concave surface of the spar to form attachment hooks for the ceramic or carbon fiber mid-chord section of the blade. A radial attachment pin extends from the mid-chord section and through a hole formed in the root portion to secure the mid-chord section to the root and spar against radial displacement during rotation of the blade.
