A Study On Acoustic Theory And Test Of Diesel Particulate Filter With Wall Flow In Diesel Engine

Exhaust noise from a vehicle is a very serious environment pollution problem in our daily life. So it is important for us to find an effective method to predict the noise of exhaust. In order to reduce the PM, the use of the Diesel Particulate Filter(DPF) is a effective measure. The use of DPF will affect the exahust noise obviously. Therefore, we should obtain the acoustic characteristics and the propagation rule of the exhaust sound in DPF. Then we can design DPF optimum. But there is short of the literature of the relationship between the acoustic characteristics and the DPF design. So it is significant to investigate the sound propagation rule in the DPF. The purpose of this paper is researching the DPF effect on exhaust noise.By using the GT-POWER software, this paper simulats the working process of engine, obtainning the exhaust state of engine, providing calculation basis of the acoustic characteristics of the DPF. This paper first discusses the simplified method of the three-dimensional acoustical model of DPF, and analyse its acoustical characteristics in Sysnoise. The transfer matrix of DPF can be calculated and visosity correction is added into the transfer matrix. At last, the insertion loss in operating condition of diesel engine is calculated by using the transfer matrix method. The significant effect of visosity correction on acoustic analysis of DPF is confirmed.In an half anechoic laboratory the engine test-bed was established, the insertion loss of DPF was measured in the rated load condition and idle condition. The comparison between experimental and calculating results validates the correctness of the acoustical model, and provides theory basis for optimizing the DPF design.