One Dimensional Backpressure Model for Asymmetrical Cells DPF 2007-01-0045
The development of the Diesel Particulate Filter (DPF) cell geometry and DPF size for new applications requires specific tools to predict the pressure drop as a function of filter characteristics, mass flow and filter loading. A 1-D permeability model is most useful for this type of work.
This paper presents the development of a 1-D physical model of DPF permeability. This model includes the symmetric and asymmetric channel shape and is able to simulate various functional phases of the DPF through its lifetime: with or without soot and with or without ash.
This kind of model needs several physical coefficients, in order to describe the flow behavior. This work explains the determination of the physical coefficients of the 1-D model. The large disparity of the literature is shown. Therefore, it is necessary to carefully determine these coefficients. Several methods were used for each functional phase of the DPF life:
1-D model and experimental measurements identification
Various methods have shown a good correlation.
The 1-D model and the physical validation were made by comparing numerical and experimental results for a different asymmetrical geometry DPF that was not used for the 1-D model establishment. This comparison is performed with and without soot and with and without synthetic ash.
The main result of the work consists in demonstrating the existence of a non-linear permeability coefficient for the soot layer.