VISCOUS CONTROLLED VORTEX DESIGN OF A 1.5-STAGE AXIAL SUBSONIC TEST TURBINE

This paper presents a Viscous Controlled Vortex (VCV) design practice of an experimental turbine. The Controlled Vortex (CV) design method was modified to take the local viscous losses into account. The method began with the analysis of initial turbine geometry of a 1.5-stage turbine, which was designed by a developed CV design approach based on a prescribed pressure distribution to resolve the circulation requirements. Then the loss corrections were combined into the terms of the CV design equations and the pressure distributions are refined. The design and optimization of the 1.5-stage axial test turbine demonstrates the effectiveness of this technique. A reduction of secondary flows and a corresponding increase of stage efficiency have achieved.