Statistical energy analysis on the damping effect of the oil pan on engine vibration

Abstract Statistical energy analysis (SEA) is used to derive the energy equations and the loss factors of the subsystems of an engine. This indicates that the engine noise can be reduced to a satisfactory level when the loss factor of the oil pan is increased and this can be achieved through the introduction of a free-layer viscoelastic material attached to the oil pan. Experimental results are obtained and they are in good agreement with the theoretical results. It is also shown that the method is usable in identifying the controlling parameters of a complex machine.