Rotordynamic forces generated by discharge-to-suction leakage flows in centrifugal pumps

LIU Quan-zhong, WANG Hong-jie, LIU Zhan-sheng

School of Energy and Power Engineering,Harbin Institute of Technology,Harbin 150001,China



Abstract:

In order to investigate the flow-induced vibration in the shroud passage of centrifugal pump and predict rotordynamic forces of centrifugal pump rotor system,an analysis of rotordynamic forces arising from shrouded centrifugal pump is presented. CFD techniques were utilized to analyze the full three-dimensional viscous,primary/secondary flow field in a centrifugal pump impeller to determine rotordynamic forces. Multiple quasi-steady solutions of an eccentric three-dimensional model at different whirl frequency ratios yielded the rotordynamic forces. The skew-symmetric stiffness,damping,and mass matrices were obtained by second-order least-squares analysis. Simulation of the coupled primary/secondary flow field was conducted,and the complex flow characteristics in the flow field of a shroud passage were achieved including the mean velocity and pressure,as well as the eddy in a large scale of flow field due to viscosity. The rotordynamic force coefficients were calculated,and the results were in good agreement with those of experiment except for the direct inertial coefficient without the consideration of whirling forces from the impeller primary flow passage.

Key words:  centrifugal pump  shroud passages  whirl  rotordynamic force  numerical calculation

DOI：10.11916/j.issn.1005-9113.2009.03.013

Clc Number:TH311

Fund: