Academic Division: Mechanics, Materials and Design
Research group: Applied Mechanics
One of the common failure modes of the diesel engine turbochargers is high cycle fatigue of the turbine wheel blades. Mistuning of the blades due to the casting process is believed to contribute to the failure mode. Laser vibrometer is used to characterize mistuning for a batch of turbine wheels through the analysis of the blade impulse response. The turbine wheel design under investigation is radial and is typically used in 6-12L diesel engine applications. Amplitudes and resonance frequencies are studied. The study also includes test results for a paddle wheel that represents a perfectly tuned system and acts as a reference. Mass spring model is developed for the paddle wheel and the model suitability is tested against the actual data. The intent is to use a similar model for the real turbine wheels and the likelihood of this is assessed based on the paddle wheel data.