Effect Of Diesel Particulate Filter For The Ultraflne Particles In Diesel Engine

As the diesel emission standards become stricter, diesel particlefilters (DPF) are being the dispensable device for reducing particulateemissions. The flow characteristics of the gas and particulate are themost important factors on the ratio of filter, the regeneration periodof filter and the lifespan of filter, so there is a significant value tostudy the gas-particle two-phase flow characteristic in DPF.Before set up to this subject, we must access to relavent knowledgeto learn enough things about the DPF. Then with the help of the Proesoftware for the modeling and the AVL Fire software for the simulation,we can do things as following:(1)To establish the experimental platform to study thecharacteristics of different engine operating conditions and bio-dieselfuel for the particulate filter capture efficiency of different particlesizes.(2)We must determine the size of the model first of all. Thus, we canmake out the model in the Proe software. It s very important to determinethe precision of the model during the modeling process, because it srelavent to the process and could influence the quality of the meshes.After this we should import the model into the Fire software. Based onthe theory about the particle-gas two-phase, we can set up a particle-gastwo-phase three-dimensional model inside and outside the DPF model usedfor the DS-engine.(3)We can use the Fire solver to simulate the maked particle-gastwo-phase flow. When the calculation ends, we can get the informationabout temperature、pressure and so on. Then we can verify the correctnessof the outputted data through access to the relavent materials.(4)Based on the calculated mathematical model for the DPF, analyzehow the inlet gas speed、diameter ratio and divergence angle worked toinfluence the uniformity of the distributions of the speed and particlesolid. The works provides an important reference to optimize the structuralparameters of DPF, and provides an important ground to exactly study onregeneration process of DPF.