Holographic Vibration Analysis and a Study of Engine Noise Control

In the case of an inline six cylinder diesel engine, first bending mode, second bending mode, bulge mode and panel modes of the cylinder block are related closely to the engine noise. The analysis of the bulge mode is carried out and the results are reported. The behavior of the engine block with the engine ignited and run, was measured using double pulsed laser holography with particular attention to the characteristics of exciting force and engine structure. In addition, oil pressure was applied to the combustion chamber of the engine with the crankshaft locked to compare the deflection characteristics with that of a running engine.