Investigation of Blade Characteristics: Performance and Efficiency of Turbine and Axial-Flow Compressor Stages

Abstract

Abstract The investigation reported in this paper deals with the flow through blade rows of turbine or axial-flow compressor stages on the basis of airfoil theory. Correlation was established by means of this theory between the aerodynamic characteristics of blade elements and the performance characteristics of the blade row. Test results from a rotating grid of sufficiently low solidity to eliminate interaction of neighboring blades are presented. It was found that the coefficients of lift of blade sections in rotating grids, especially near the hub of the wheel, are higher than might be expected from wind-tunnel tests. Methods of experimental aerodynamic investigation were adapted to the rotating-blade grid for the determination of the profile drag, in an attempt to broaden the basis for a rational determination of the efficiency of turbine and compressor stages.