Turbulent operation of diesel oxidation catalysts for improved removal of particulate matter

This paper proposes that a diesel oxidation catalyst (DOC) operating within the fully turbulent flow regime is an efficient means of reducing the contents of particulate matter in the exhaust gases. The suggested mode of operation is in contrast to the fact that the DOCs are typically operated within the laminar flow regime. In the paper, the particle trapping efficiency and pollutantconversion in turbulent ceramic DOCs are calculated using both mass-transfer correlations available in literature and computational fluid dynamics (CFD). It is shown that a turbulent DOC substantially increases the removal of small particulates from the exhaust gases. This indicates the potential of the aftertreatment system to comply with the forthcoming number-based emission legislations on particulate matter. In addition, the turbulent DOC can be used to optimize the overall performance of acombined system consisting of a DOC and a diesel particulate filter