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Open Citations Database
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Citation Details
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Title:
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Experimental Investigation of Catalytic Soot Oxidation a and Pressure Drop Characteristics in Wall-Flow Diesel Particulate Filters
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Category(s):
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Diesel Particulate Filters
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Author(s):
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George Stratakis
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Other:
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PhD Thesis
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Publisher:
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University of Thessaly
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Year:
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2004
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Pages:
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1-165
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Volume:
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2004
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Abstract:
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This PhD thesis examines certain aspects of diesel filter regeneration by use of fuel additives that proved to need further investigation. These include the reaction scheme and kinetics parameters of the catalytic regeneration, the role of the Volatile Organic Fraction (VOF) of the particulate, the study of soot and exhaust flow maldistribution in the filter and the study of pressure drop parameters as the permeability of the ceramic wall and the permeability ? density of the particulate layer. All these studies were based on specially designed experiments, on the engine bench and on purpose designed test rigs. As regards the
reaction scheme, the range of catalytic activity of Ceria with regard to the soot and VOF
oxidation, as well as the Ceria re-oxidation by exhaust gas oxygen was determined, along with the respective apparent kinetics parameters (activation energy values). As regards the VOF, the VOF content of soot produced by the specific engine was mapped in the operation range of the engine. Also, the role of VOF in the low-temperature regeneration process was demonstrated and explained. Early in this study, it was found that the exhaust gas flow distribution between the filter channels was interacting with the soot loading distribution and VOF adsorption ? desorption. For this reason, specific series of experiments were designed and conducted. The results demonstrated an unstable behaviour of soot maldistribution during loading and regeneration. This behaviour was found responsible for a major part of the significant discrepancies observed between 1D and 2D (axisymmetric) models and experimental findings by numerous researchers. Moreover, the above-mentioned maldistribution behaviour prohibits any valid correlation between pressure drop across the filter and soot loading mass. This is a problem for the control system of the engine exhaust treatment, because the filter pressure drop signal was traditionally an essential sensor input signal for the engine management. In addition to the soot maldistribution between center and periphery of the filter, it was found that the soot layer thickness in a single channel could also present a certain degree of inhomogeneity. Another major objective of this study was to support improved modeling of the process. This was partly succeeded as one may deduce from the extensive validation results of 1D and 3D codes, which are now routinely being applied as engineering design tools.
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Full Text at:
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http://www.mie.uth.gr/labs/ltte/pubs/PhD_Stratakis.pdf
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Times Viewed:
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3116
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Submitter Details
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Name:
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George Stratakis
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Email:
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gstrat@uth.gr
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Organization:
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University of Thessaly
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Date Submitted:
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2004-05-06
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