Overall aerodynamic performance of an annular flat-plate airfoil cascade
THE aerodynamic design of turbomachiner y blading is specified by means of design systems wherein the flow is assumed to be two-dimensional with losses determined from empirical correlations. However, with the continuing requirements for improved efficiency and increased thrust-to-weight ratio, it is evident that new analyses that consider the fundamental three-dimensional flow phenomena existing in blade-row flow passages must be developed, verified by concise data, and subsequently implemented in the design process. Numerical solutions are currently being developed to predict the three-dimensional flow through turbomachine blade rows. To overcome the complexities associated with the flow conditions and the internal geometries, these numerical solutions of necessity involve many computational and physical assumptions. This paper describes experiments performed in a large-scale, subsonic annular cascade facility specifically designed to provide three-dimensional aerodynamic data suitable for code verification. In particular, to minimize the complexities associated with cascade geometry and complex airfoil profiles, the detailed overall threedimensional aerodynamic performance of an extensively instrumented flat-plate airfoil cascade has been experimentally determined over a range of incidence angle values. All of the resulting data are analyzed and correlated with appropriate predictions. Contents