Research on transient characteristics and cavitation phenomenon of faulty rotor pump

Abstract

In contemporary refrigeration systems, the refrigerant pump serves as a critical power transmission device. This study examines the exacerbation of cavitation in refrigerant-mediated rotor pumps under multifactorial failure coupling, analyzing its correlation with performance degradation and pulsation signals. Through experimental validation, we establish a computational model that evaluates how rotational speed, pressure differential, fatigue pitting severity, crack depth, and gap dimensions collectively influence cavitation dynamics.The results demonstrate that cavitation intensity escalates nonlinearly with increasing rotational speed. Specifically, vapor fraction increases by 65.07 %, 65.24 %, and 57.76 % for pitted, cracked, and clearance-defective rotors respectively when the speed is elevated from 1305 to 1450 rpm. While higher pressure differentials lead to an overall reduction in cavitation (from 15.22 % to 14.74 % vapor fraction), localized cavitation intensifies at the inlet end-face meshing zones.Progressive failure severity reveals distinct nonlinear responses: an increase in pitting depth from 0.1 mm to 0.4 mm and crack propagation from 0.25 mm to 1 mm results in local vapor fractions rising by 3.26 % and 3.80 %, respectively; conversely, gap expansion from 0.1 mm to 0.25 mm induces a reduction of approximately 3.59 %. The established methodology provides an effective framework for diagnosing cavitation-coupled failures in rotary hydraulic systems.