Low noise suppression method for automotive engine intake/exhaust pipe based on empirical mode decomposition

DOI:	10.11809/bqzbgcxb2023.10.039
Keywords:	empirical mode decomposition; engine; air intake/exhaust; low noise suppression; transmission loss; envelope average value
Abstract:	In order to reduce the noise in the intake/exhaust pipe of automobile engine and improve the stability and service life of the engine, an empirical mode decomposition (EMD) based method for suppressing low noise in the intake/exhaust pipe of automobile engine is proposed. The engine exhaust fundamental frequency noise and multi cylinder intake noise are calculated respectively, and the resonance noise of engine intake and exhaust is obtained. The noise components of the engine are constructed based on the empirical mode decomposition algorithm. By calculating the envelope average of its maximum and minimum, the residual amount of each noise point relative to the extreme point is obtained, and the noise signal of the engine is decomposed into different unit components. Under the noise convergence coefficient and noise mode decomposition mechanism, a low noise suppression algorithm for engine intake and exhaust is designed. The experimental results show that the algorithm has a certain effect on noise suppression; The more mufflers, the greater the noise transmission loss; In the muffler volume, the transmission loss is proportional to the expansion ratio and the expansion structure length respectively; When the pipe diameter is more than 36mm and the pipe length is 150 mm, the noise suppression effect is the best. When the engine is running at full power, it is necessary to ensure that the pipe diameter is less than 32 mm and the pipe length is 150 mm.
Issue:	Vol. 44 No. 10 (2023)
Published:	2023-10-28
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