3-D Catalytic Regeneration and Stress Modeling of Diesel Particulate Filters by ABAQUS FEM Software

Abstract

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Catalyzed diesel particulate filter modeling

“…Following the developments of DPF models, the first stress analysis calculations involved 2D meshes (Umehara andNakasuji 1993 , Miyairi et al 2001 ), which evolved to 3D in the course of the last decade (Pontikakis et al 2002, Barataud et al 2003, Kuki et al 2004 ). Related to the mesh selection are the structural properties of the material.…”

“…To estimate the complete temperature field, the first researchers (Umehara and Nakasuji 1993 , Miyairi et al 2001 ) interpolated data from several thermocouple measurements. The main contribution of validated DPF models (Pontikakis et al 2002, Kuki et al 2004 in the frame of direct coupling to stress analysis was the replacement of these rough approximations with accurately calculated 3D temperature fields, which were exported to stress analysis solvers. This procedure was repeated typically every time step to obtain the full history of stresses during a regeneration and estimate the global critical points , as shown in Figure 62 .…”

Oxygen diffusion modeling in diesel particulate filter regeneration

“…Assumption 1 (identical behavior of all channels) is also raised in more comprehensive 2‐D models, which take into account the heat losses and flow maldistribution (Aoki et al, 1993; Haralampous et al, 2003; Konstandopoulos et al, 2001; Miyairi et al, 2001). Three‐dimensional models aimed at more detailed temperature and thermal stress predictions have also been published (Pontikakis et al, 2002).…”

Experimental investigation of catalytic soot oxidation and pressure drop characteristics in wall-flow diesel particulate filters

“…Such stresses may be enhanced by the modular structure of these filters that consist of a number of monolithic modules connected by special adhesive cement. Thus, in transient regeneration experiments where the operation point suddenly changes to very low flowrate, 3-D effects become prevalent, with a well-distinguished evolution of regeneration in different channels, as shown in [104].The onset of regeneration is again observed in the central channels. Although the observed delay in the onset of regeneration in the periphery is quite significant, (order of several minutes as shown in the Figure), the maximum temperatures observed in the periphery are equivalent, or even higher, than those observed at the central channels.…”

“…The lower temperatures also mean the appearance of high thermal gradients at this block. The thermal gradients are associated with thermal stresses that under certain conditions may lead to filter failure [104]. In this case the predicted delay in the regeneration of the outer blocks of the filter is signifigantly less than the measured.…”