The WOLA marine high-speed diesel engines diagnostics using vibro-acoustic methods

In the paper, some results achieved during the tests of high-speed marine diesel engine WOLA 57H6Aa type are presented. This type of engine is still broadly use on Polish Navy vessels and on some civilian ships built in Polish shipyards, mostly as auxiliary or emergency generator. Several types of engine malfunction had been simulated especially in fuel injection system and in valve gear mechanism. The malfunctions were connected with fuel valve opening pressure, intake and exhaust valves clearances. During the tests engine speed and load had been changed in tolerant operation range. The tests were devoted to prepare some new diagnostic methods, which could be used on these types of marine diesel engines. Diagnostic methods, which based on vibration and acoustic signals analysis are usually sensitive on engine load and speed changes. During the tests, different methods based on vibration and acoustic signals processing in frequency domain were used. Set of applications possible to use by B&K PULSE system together with acoustic and vibration sensors were applied to analyse of signals changing by different types of simulated malfunctions. Aim of the research was to check if the acoustic and vibration signals generated by the engine systems and components analysed by B&K PULSE system with CPB measurement give possibility to find such parameters, which are unequivocal, strongly connected with different object structure parameters, easy to asses and measure.