Abstract: A turbine flowpath structure includes a first generally U-shaped flowpath channel having a first leg having a first inwardly facing side shaped as a turbine blade suction-side airfoil surface, a second leg having a second inwardly facing side shaped as a turbine blade pressure-side airfoil surface, and a web connecting the first leg and the second leg, wherein the web has an inwardly facing inner flowpath surface. There is typically provided a spar that engages at least one of the first leg and the second leg. In one application, there is a plurality of the generally U-shaped flowpath channels arranged around the periphery of a turbine disk, and a plurality of spars positioned between each pair of adjacent generally U-shaped flowpath channels to anchor them to the turbine disk.

Abstract: A turbofan engine includes in serial flow communication a first fan, second fan, multistage compressor, combustor, first turbine, second turbine, and third turbine. The first turbine is joined to the compressor by a first shaft. The second turbine is joined to the second fan by a second shaft. And, the third turbine is joined to the first fan by a third shaft. First, second, and third cooling circuits are joined to different stages of the compressor for cooling the forward and aft sides and center bore of the first turbine with different pressure air.

Abstract: A turbine blade includes a hollow airfoil integrally joined to a dovetail. The airfoil includes a perforate first bridge defining a flow channel behind the airfoil leading edge. A second bridge is spaced behind the first bridge and extends from a pressure sidewall of the airfoil short of the airfoil trailing edge. A third bridge has opposite ends joined to the pressure sidewall and the second bridge to define with the first bridge a supply channel for the leading edge channel, and defines with the second bridge a louver channel extending aft along the second bridge to its distal end at the pressure sidewall.