Systematic Evaluation of Cooled Turbine Efficiency

This paper presents a status report of our current ability to evaluate cooled turbine performance, and is based both upon fundamental reasoning as well as our accumulated experience. During the early portion of the examination, a dimensionless entropy rise emerges as a natural quantitative measure of airfoil cascade aerodynamic performance. Later, similarity principles are used to show that reliable experiments will, at least for the time being, require the constraint of a large number of parameters. Finally, an assessment of the analytical art indicates great promise, although a substantial amount of ground remains to be covered.