Experimental study on the relationship between combustion and noise and vibration in a gasoline engine

Abstract

An experimental study was conducted to clarify the relationship between engine combustion and noise and vibration, and concerning design indexing for its suppression. This study focused on the vehicle interior noise caused by combustion in which vibration transmission is the main component at high speed and high load region. A phenomenon in which both the combustion's exciting force and the structure's exciting force are combined is defined as vehicle interior noise caused by combustion. Conventionally, combustion and noise and vibration are often discussed in terms of the average cycle, but considering the nonstationary property of noise and vibration, in this paper analyzed the characteristics of both exciting force for vibration in cycle-by-cycle based on clustering analysis. The engine vibration is affected by heat release characteristics even with the same engine structure specifications. The heat release characteristics were determined as indicators for the combustion's exciting force. The engine vibration is affected by piston specifications even with the same heat release characteristics. The piston tilt and translational displacement were determined as indicators of the structure's exciting force. This paper clarifies the influence of each exciting force on vibration and discusses indexing that contributes to design.