135 / 2021-03-31 12:50:07

Acoustic analysis in a pipe by using Analytical SEA (Optimization of an automobile exhaust pipe)

Vibration,Automobile Exhaust Pipe,Acoustic,Statistical Energy Analysis,Optimization

Vibro-acoustics and Structure-borne Noise

Conventionally, the exhaust noise of automobiles has been considered as one of the factors of exterior noise of automobiles, and there is a need to reduce this exhaust noise. Transfer matrix method has been used for a long time to analyse the noise of automobile exhaust pipes, and it is effective for analysing the acoustic propagation in the exhaust pipe. However, since the acoustic propagation in the pipe is assumed to be a plane wave, the optimization to reduce the discharge noise is expensive. In this paper, statistical energy analysis (SEA) method was used to analyse the acoustics of a straight pipe and a bent pipe. SEA is a method of expressing energy transfer using the internal loss per element and the transfer coefficient between elements, and SEA was applied to the acoustic analysis by calculating the acoustic pressure loss in the pipe from the acoustic energy loss. In addition, for the internal acoustics of an automobile exhaust pipe, we used analytical SEA to optimize the structure to maximize the loss.