A turbine airfoil has an airfoil-shaped core and a skin extending about the outer peripheral surface of the core. The core and/or the skin are configured such that a plurality of cooling channels is formed between them. In one embodiment, the cooling channels are formed by a plurality of radially extending channels in the core. In another embodiment, the cooling channels are formed by providing a wave-shaped skin such that, when the skin is attached to the outer peripheral surface of the core, the cooling channels can be formed in the space between the outer peripheral surface of the core and each wave of the skin. Such airfoil constructions can allow the inclusion of different materials in the airfoil. Further, such constructions can allow greater flexibility in the formation of cooling channels. Moreover, such constructions can help to achieve thinner outer walls and near surface cooling of the airfoil.
STATEMENT REGARDING FEDERALLY SPONSORED DEVELOPMENT
 Development for this invention was supported in part by Contract No. DE-FC26-05NT42646 awarded by the United States Department of Energy. Accordingly, the United States Government may have certain rights in this invention.