Performance of Inward Radial Flow Turbines under Non-Steady Flow Conditions

Abstract

The paper describes theoretical and experimental work on pulse operation of inward radial flow turbines, together with certain essential steady flow data. Power measurement was by means of a specially developed high speed dynamometer, capable of speeds up to 10 000 rev/min, which is described in some detail. Steady flow tests confirmed the expected trends of mass flow and torque as functions of turbine speed and overall pressure ratio, and in addition proved the reliability, consistency and accuracy of the dynamometer. The unsteady flow analysis of Appendix 1 which is unique in incorporating a very full description of rotor geometry as well as of the complex nozzle-rotor interspace conditions, was applied to two particular experimental cases and gives good agreement with respect to pressure variation in the pipe system, turbine volute and at nozzle exit, but rather less satisfactory agreement with respect to power. Further theoretical work is summarized at the end of the paper.