Literature Research on Experimental Investigations of Automotive Turbocharger Rotordynamics

Contemporary turbochargers are high-speed rotating devices, commonly supported by full floating bearings or semi-floating bearings. Depending on the size and operational speed of the turbocharger, rotordynamics significantly changes. Industrial turbochargers are operating below 20.000 RPM and their rotor weight is substantial, leading to quasilinear rotordynamics behaviour. By contrast, automotive turbochargers are rotating up to 300.000 RPM with non-linear rotordynamics characteristics. Due to this non-linearity, rotor movement is intense, and bearing load is dynamically changing all the time. The consequence is reduced lifespan of the turbocharger. In this paper, the effect of changing bearing clearances, as well as the differences between semi-floating and full floating bearing constructions will be described based on journal papers scientific publications on the topic. Also, the damping and whirling phenomenon inside a bearing system will be investigated and presented in a comprehensive literature research on automotive turbocharger rotordynamics.