Abstract: A secondary flow, turbine cooling air system for the uniform cooling of high pressure turbine module components such as the turbine shroud, turbine blade tips, turbine nozzle, transion liner, and turbine bearing support housing in a recuperated gas turbine engine is provided. The secondary flow turbine cooling system provides uniform cooling air having a similar pressure and temperature in a recuperated gas turbine engine as the compressor discharge air of a non-recuperated gas turbine engine. A method for uniform cooling of high pressure turbine module components using the secondary flow turbine cooling air system is also provided.

Abstract: A lower stress and higher service life curvic coupling design is disclosed for use on coupling mechanisms for assembly of components that comprise rotating elements, such as impellers, turbine wheels and couplings for gas turbine engines and other types of engines having highly stressed components. The curvic coupling design includes a compound fillet radius, comprised of a large and a small radius, located between the root and the pressure surface of all splined teeth on the torque transmitting coupling halves. The larger radius, with its lower stress concentration, is positioned in the root area where the background hoop stresses act, thereby resulting in a lower fillet peak stress value. The smaller radius smoothly connects the larger radius with the pressure surface, minimizing the penetration of the fillet surface towards the mating tooth, thereby allowing proper clearances to be maintained.

Abstract: A lower stress and higher service life curvic coupling design is disclosed for use on coupling mechanisms for assembly of components that comprise rotating elements, such as impellers, turbine wheels and couplings for gas turbine engines and other types of engines having highly stressed components. The curvic coupling design includes a compound fillet radius, comprised of a large and a small radius, located between the root and the pressure surface of all splined teeth on the torque transmitting coupling halves. The larger radius, with its lower stress concentration, is positioned in the root area where the background hoop stresses act, thereby resulting in a lower fillet peak stress value. The smaller radius smoothly connects the larger radius with the pressure surface, minimizing the penetration of the fillet surface towards the mating tooth, thereby allowing proper clearances to be maintained.