Specificity of Modeling of the Structure-Borne Noise of the Diesel Engine from the Working Process in the Acceleration Mode

In urban traffic conditions, the car's engine mainly operates in non-stationary modes. In this case, the engine noise may exceed the values corresponding to the stationary mode. The article deals with the issues of modeling of the working process and structure-borne noise of a diesel engine in the acceleration mode. The factors that cause differences in the working process during acceleration (deterioration of the processes of mixture formation and combustion, an increase in the ignition delay period, thermal inertia of engine parts, etc.) are analyzed. A method for the structure-borne noise from the diesel engine operating process calculation in the transient mode is presented. The results of the study of the structure-borne noise of the 6-cylinder diesel engine (D=10,7cm, S= 12,4cm) in the acceleration mode, performed using the considered technique, showed that the total sound power level from the working process for the studied range of crankshaft speeds is 2...3 dB higher than the values for the corresponding speeds in stationary modes for full load performance.