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This study deals with a coupled experimental and modeling approach of Diesel Particulate Filter cracking. A coupled model (heat transfer, mass transfer, chemical reactions) is used to predict the temperature field inside the filter during the regeneration steps. This model consists of assembled 1D models and is calibrated using a set of laboratory bench tests. In this set of experiments, laboratory scale filters are tested in different conditions (variation of the oxygen rate and gas flow) and axial/radial thermal gradient are recorded with the use of thermocouples. This model is used to build a second set of laboratory bench tests, which is dedicated to the understanding of the phenomena of Diesel Particulate Filter cracking.

One of the challenges in the automotive industry is to develop new vehicles and new technologies with minimal costs. In this context, modeling becomes an important tool for the design of future technologies by reducing the number of tests needed to develop a new exhaust system. With the emergence of future European standards, which are more restrictive on NOx and takes account of the differentiation between NO and NO₂ emissions, European manufacturers have to describe precisely the formation and the behavior of NO₂ in the aftertreatment systems. The aim of this study is to improve the one-dimensional aftertreatment models developed by Renault by introducing the NO₂ contribution from the engine to the tailpipe. The first part of this study focuses on the adaptation of aftertreatment systems models in order to differentiate NO and NO₂. Thus different global kinetics models for the Lean NOx-Trap System were studied.

With more and more stringent standards concerning soot mass and number at the tailpipe of Diesel vehicles, the control of Diesel Particulate Filter regenerations is becoming a key feature for car manufacturers. When regulations on particle number will appear, even low cracking of the DPF could lead to the non-conformity of the filter with respect to the regulations. Strategies of regeneration control are often developed for the most critical regeneration conditions for DPF durability, the so-called “Back to Idle” tests. The development of those strategies is time-consuming, since the influence of the engine tuning on regeneration control means to load DPF for each engine tuning tested. Moreover, as the best engine tuning strategy is determined relatively to other strategies results, one needs very repeatable tests conditions and soot loading in terms of distribution and soot reactivity. This repeatability is very hard to get in real conditions.