Analysis On Muffling Characteristic And Flow Uniformity Of The Rotary Radial Diesel Particulate Filter

It is one of the important research topics to decrease the diesel exhaust noise anddiesel particle simultaneously. After-treatment technology of engine must beundertaked to meet the increasing stringent diesel engine emission regulations.Currently, Diesel Particulate Filter (DPF) is recognized as one of the most effectivedevice to solve the diesel particulate emission promble. The rotary radial dieselparticulate filter studied in the paper is a DPF with continuous microwaveregeneration, having the functions of continuous trapping particulate and exhaustsilencer simultaneously. Basing on ensuring the function of trapping particle, how tostudy immanent action mechanism between noise characteristics and flow uniformityeffectively is the key issue to resolve in the design optimization for trapping andmuffling performance of the rotary radial DPF.Therefore, supported by the projects such as National “863” Project of China(2008AA11A116), National Natural Science Foundation of China (50876027) and theNational Natural Science Foundation of China (51176045), muffling characteristicsand flow field uniformity of the rotary radial DPF is researched in detail. The primaryworks and innovation of this thesis are summarized as follow:(1)The finite element method was applied to establish the acoustic model.Depending on the model, muffling characteristics and transmission loss curve hadbeen gotten by using Sysnoise. By grey relational analysis, the effects of structureparameters on muffling characteristics in the rotary radial diesel particulate filter werestudied.(2)Based on gas-particle two-phase flow theory, the integrated3-D gas-particletwo-phase flow mathematic model of the rotary radial DPF was established and solvedby using Fluent. The distribution of pressure, velocity and turbulence kinetic energyhad been obtained and analyzed.(3)Based on numerical simulation method, the flow uniformity coefficient isintroduced to analyze the effect of rotary radial type particulate trap structureparameters (such as expanding angle, diameter ratio, length of filter body), inletvelocity and the flow uniformity as well as the loss of resistance. It can provide atheoretical basis for the design to eliminate regeneration noise due to reflux and eddycurrent phenomenon in the rotary radial DPF.