Plane Cascade Solution with Injection

Abstract

RESENT analytical methods for the estimation of the aerodynamic performance of film-cooled turbine blades, e.g. Refs. 1-3, require that the pressure distributions be obtained by experimental or computational analysis of flow over the uncooled turbine blade profile. This uncooled turbine blade pressure distribution is assumed to be unaffected by coolant flow and is used for all performance calculations regardless of the amount or location of coolant flow injection. A study was made to determine if these aerodynamic performance prediction methods could be improved by including the interaction effects of the coolant flow on primary flow blade surface pressure distributions. A brief description of the technique used in calculating the cooled turbine blade pressure distributions and the result of using these pressure distributions with existing performance analysis will be given in this Note. Analysis A means of calculating the coolant flow disturbed blade pressure distribution was developed for use with cooled turbine blade aerodynamic performance analysis. A twodimensional flow calculation using spanwise averaging of coolant injection flow characteristics was used in calculating the cooled turbine blade pressure distributions, since the performance analyses are two-dimensional and use a similar spanwise averaging of coolant flow properties. From the many existing methods for calculating two-dimensional, inviscid subsonic flow through a cascade, the distributed