Vibro-acoustic methods in marine diesel engines diagnostics

Vibro-acoustic diagnostic methods which are used on marine high-speed diesel engines with turbochargers are presented in this paper. Vibration and acoustic signals generated by turbochargers need different signal processing methods to be effective and faultless in turbochargers diagnostics. Diagnostic methods which based on vibration and acoustic signals analysis are sensitive on engine load and speed changes. Methods presented in this paper based on vibration and acoustic signals processing in time and frequency domain. Using this methods checking technical condition of the turbochargers and its rotors and bearings without stopping the engine and dismantling it is possible. Examples of radial-flow rotor turbine overgrown by carbon soot and axial-flow rotor turbine without turbine blades, sound intensity level of turbocharger and acoustic spectrum of turbocharger in octave mode acoustic spectrum of turbocharger in octave mode for two different technical conditions, acoustic and vibration signal spectrum of the turbocharger, vibration acceleration amplitude of first harmonic for three turbochargers, values of harmonic vibrations of accelerations equivalent of turbine blades number, amplitude of vibrations accelerations in frequency domain for turbocharger in good and bad technical conditions are presented in the paper.