A Novel Vibration Monitoring Method for Marine Turbocharger Turbine Blades Based on Pressure Pulsation Measurements

There is currently no simple way to determine which blade has the largest vibratory strain due to mistuning effect. A need is therefore raised for a cost-effective and quick method to identify the blade with the largest deformation in working condition.A vibration monitoring method based on pressure pulsation (PP) measurements is proposed in this paper. First, the natural frequency of turbine blades at room temperature is collected and the range of resonance speed of turbine blades is predicted. Secondly, the resonance speed range is traversed by ramping up turbine speed, and the unsteady PP, blade phase discrimination signals and turbine speed are collected synchronously. Then a zero-phase band-pass filter is deployed to filter the PP signal. Finally, the time-domain signal segment with the largest amplitude is intercepted. Combined with the blade phase discrimination signal, the turbine blade with the largest amplitude of blade vibration can be determined. The experimental results show that the proposed method can identify the blade of a turbocharger radial turbine with the largest vibratory amplitude caused by the 5th order of excitation from the measured PP signal.