3 - Principles of performance analysis for axial turbines

Abstract

This chapter addresses the background theory behind the design and performance analysis of multi-stage axial turbines, making use of dimensional analysis and related to the Rolls-Royce test stage correlation that was published in 1965 and to the program FIPSI. It explains the use of dimensional analysis, based upon local dimensionless variables, to provide a unified framework for performance analysis of axial turbines that integrates the three main fluid dynamic design activities—namely, choice of local dimensionless design duty coefficients, velocity triangle design, and fluid flow considerations. A “screen-dump” of a typical three-stage turbine design is shown together with a summary of the input design data. To give some idea of the overall design sequence for such a machine, the various steps are related through a flow chart.