Effect of splitter blades on turbine mode of low specific speed pump

V. Kaplan Department of Fluid Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technická 2896/2, 61699 Brno, Czech Republic

^* Corresponding author: Jiri.Bezdicek@vut.cz

Published online: 4 July 2024

Abstract

The use of pump in turbine mode is an evolving research field. This article is mainly focused on the influence of splitter blades on the turbine mode of pump exclusively. CFD analysis on low specific speed pump geometry was performed. The geometry of sidewall gaps spaces between the rotor and stator system was also included in the computational model. Flow phenomena were compared with quantification of losses. In this case, entropy production theory was used for loss analysis. The effect of different computational meshes and turbulence models on the low-specific speed machine was also questioned. The numerical approach was used not only to obtain turbine characteristics and evaluate the effect of splitter-blades on the machine, which was main goal of this work but also to describe flow or carry out hydraulic loss analysis and visualise areas of most dominant losses. Volumetric efficiency, hydraulic forces, and influence of flow in sidewall gaps on torque generation were also investigated. The numerical model was validated using experimental data. Probable reasons for the difference between the experiment and simulation were estimated.