Experimental validation of a rotor delevitation model with quantified severity indicators

This paper presents the experimental validation of BBSim: a non-linear model for simulation of rotor delevitation in an active magnetic bearing system with backup bearings (BBs). The rotor delevitation model’s purposes are to understand the dynamics involved during delevitation and to quantify the severity of the delevitation event. The subsequent challenge consists of validating both the delevitation dynamics and the impact of the rotor on the backup bearing as a quantitative measure of delevitation severity. Severity indicators are derived from the relationship between the rotor’s impact and the average lateral rotor speed after delevitation. Model validation employs both the defined severity indicators and the rotor delevitation orbit characteristics as basis for comparing experimental and simulated results. The severity indicator validation confirms the rotor lateral kinetic energy during delevitation as a satisfactory predictor of the BB impact forces. Furthermore, calibration of the simulation model together with the subsequent validation process affirms the model’s validity