Some Experimental Results of Two Concepts Designed to Increase Turbine Blade Loading

Abstract

A number of advanced blade concepts to efficiently increase turbine blade loading are being experimentally investigated. Tests made with a single-stage turbine rig have shown two of the advanced blade designs (i.e., the tandem blade and jet-flap blade) to be potentially promising. The design of these two blades and a base plain blade, together with a comparison of the test results, are presented. All three blades were designed to the same velocity diagrams. The design diagrams are based on free-vortex flow and have a significant amount of flow deceleration across the rotor hub. Test results of the three rotor configurations, obtained with the same stator assembly, are presented. The results include turbine airflow, efficiency, and reaction characteristics along with rotor exit surveys.