A Theoretical Study of the Performance of a Number of Different Axial-Flow Turbine Configurations under Conditions of Pulsating Flow.

摘要

The work described in this report is a continuation of an earlier investigation aimed at determining the best turbine configuration for operation with the pulsating flow occurring in a constant-volume gas turbine. In the earlier investigation, a radial-inflow turbine was chosen for analysis. This initial work is now extended to a number of different two-stage, axial-flow turbines. The method of turbine performance prediction for steady-flow operating conditions was developed for a single-stage, axial-flow turbine. During this development it was found that existing correlations for determining turbine loss characteristics at high negative angles of incidence were inadequate and consequently a modified approach had to be developed. Four basic two-stage turbines, each having different blade angles, as well as several versions of one of these, were chosen for analysis. The mean efficiencies of these machines for pulsating-flow operating conditions were estimated by using a quasi-steady method of analysis. The results obtained for the selected turbines are presented and compared with the results for the radial-inflow turbine. A configuration is proposed that could possibly give better mean efficiencies under pulsating-flow conditions than those actually considered. (Author)