Aerodynamic Characteristics of Steam Turbine Reaction Stages. (Aerodynamic Characteristics of a Single Stage)

The aerodynamic characteristics of reaction stages of a large steam turbine have been studied for the basis of performance improvement. The principal results are as follows. (1) Loss distribution in the stationary row is similar to the two-dimensional cascade test results. (2) In the rotating row, profile losses are more than double those of the stationary blades, and secondary losses near base section are fairly larger than the prediction based on the cascade test results. (3) Turning angles of flow through the rotating row near the base diameter are fairly larger than the prediction. (4) Stage efficiency distribution along the blade height shows performance improvement near the base diameters.