3D flow simulation by a hybrid two-phase solver for the assessment of liquid/gas transport in a volute-type centrifugal pump with twisted blades

Authors

Markus Hundshagen - Chair of Hydraulic Fluid Machinery, Ruhr University Bochum, Germany
Kevin Rave - Chair of Hydraulic Fluid Machinery, Ruhr University Bochum, Germany
Michael Mansour - Mechanical Power Engineering Department, Faculty of Engineering, Mattaria, Helwan University, Egypt; Lab. of Fluid Dynamics & Technical Flows, University of Magdeburg "Otto Von Guericke", Germany
Dominique Thevenin - Mechanical Power Engineering Department, Faculty of Engineering, Mattaria, Helwan University, Egypt
Romuald Skoda* - Chair of Hydraulic Fluid Machinery, Ruhr University Bochum, Germany

Abstract

A hybrid two-phase flow solver is proposed, based on an Euler-Euler two-fluid model with a continuous blending of a Volume-of-Fluid method when phase interfaces of coherent gas pockets are to be resolved. In a preceding study on a 2D-bladed research pump with reduced rotational speed, the transition from bubbly flow to coherent steady gas pockets, observed in optical experiments with liquid/gas flow, could well be captured by the hybrid solver. In this study, the experiments and solver validation are extended to an industrial-scale centrifugal pump with 3D-blading and realistic rotational speed. The solver is combined with a population balance modeling, and a scale-adaptive turbulence model is employed. Compared to the 2D-bladed pump, the transition from agglomerated bubbles flow to attached gas pockets is shifted to larger gas loading, well captured by the simulation. The pump head drop with increasing air load is also reproduced, showing the hybrid solver's validity for realistic pump operation conditions.