soot consuming rate in diesel particulate filter
I am doing a simulation of diesel particulate filter regeneration, namely soot combustion trapped in the filter.
The soot exists in the filter in two formats. The first one is soot cake which itself is porous media. The soot cake is not in contact with catalyst whose combustion is called slow oxidation. while the soot in the porous filter wall is in contact with catalyst whose combustion is called fast oxidation.
The computation domain in the paper I am trying to reproduce is as follows:
what confuses me is a description in the paper 'in the porous wall of the filter, both contributions of slow and fast oxidation were implemented . in the cake, only the slow oxidation was implemented'
Does this mean the soot consuming rate in the porous wall of the filter is the summation of slow oxidation and fast oxidation? I am wondering is this right? I believe the soot oxidation rate in the porous wall is merely fast oxidation rate.