Article

Journal of Engineering Research

, 4:19

First online:

Open Access This content is freely available online to anyone, anywhere at any time.

Experimental and numerical studies on the effect of inlet pressure on cavitating flows in rotor pumps

  • Yingyuan LiuAffiliated withInstitute of Process Equipment, Zhejiang University Email author 
  • , Leqin WangAffiliated withInstitute of Process Equipment, Zhejiang University
  • , Zuchao ZhuAffiliated withDepartment of Mechanical Engineering & Automation, Zhejiang Sci-Tech University

Abstract

This paper aims to investigate the effect of the inlet pressure on cavitating turbulent flows in a rotor pump through experimental and numerical studies. In experimental studies, both the flow rate and the inlet/outlet instantaneous pressures with various inlet pressures were monitored. The results show that the instantaneous pressures of the inlet/outlet pulsate periodically and its dominated frequency changes with the inlet pressure. In numerical studies, a simplified 2D numerical model for analyzing the cavitation flows in the rotor pump was established and verified by the experimental data. Meanwhile, the influences of the inlet pressure on the volumetric efficiency, the distribution of bubble volume fraction and the pressure fluctuation were included. The results present that the numerical model with cavitation is more reasonable for the rotor pump than the single phase model and the inlet pressure indicates a strong influence on cavitation characteristics. Firstly, the volumetric flow rate ratio decreases at the inlet, but increases at the outlet with the inlet pressure on the decrease. Moreover, the peak of the inlet flow rate ratio offsets backward as the inlet pressure decreases, but the peak of outlet flow rate ratio does not display any delay. Secondly, as the inlet pressure decreases, the volume fraction of the vapor phase increases and its peak also offsets backward. Finally, both pressures at suction and the discharge sides present a sudden increase at a certain moment. For a high inlet pressure, the pressure mutation occurs when the two rotors are fully engaged with each other, while the time for pressure mutation delays for a low inlet pressure.

Keywords:

Cavitation dynamic mesh inlet pressure rotor pumps