Experimental study on the impact of viscosity index and contaminant concentration on the vibration characteristics of a Dual-Disc flexible rotor

Abstract The vibration of rotor systems is significantly affected by solid particle contaminants, leading to reduced system performance and, in some cases, failure. In this paper, the influence of lubricant viscosity index and solid particle contaminants on the vibration characteristics of a dual-disc flexible rotor was examined. A dual-disc flexible rotor test rig was established. Extensive experiments were carried out by mixing various concentrations of contaminants with four types of lubricants, each with a different viscosity index. The results indicated that nonlinear vibration phenomena were induced by the presence of contaminants. Significant changes in the rotor’s vibration characteristics were observed when contaminants were introduced into lubricants of varying viscosity indices, altering the system’s maximum amplitude and critical speed. These alterations included abrupt amplitude shifts and periodic variations in critical speed. This study provides important experimental evidence for the operation of dual-disc flexible rotor systems in complex environments and supports the further optimization of rotor design and safe operational strategies under contamination conditions.