Performance of Asymmetric Particulate Filter with Soot and Ash Deposits: Analytical Solution and Its Application

Abstract

With ever-tightening emission regulations, particulate filters are critical for internal combustion engines to meet the stringent particulate matter emission standards. A fast way to predict the filter performance, instead of numerically solving the governing differential equations, is needed for filter design and selection, real-time control, malfunction detection, and deposit load sensing. Approximate analytical solutions for wall flow filters, considering asymmetric channels and arbitrary deposit amounts, are derived by a technique of successive approximation. The analytical predictions of filter pressure drop have been validated against both steady state and transient experimental measurements. Moreover, over a broad range of filter operating conditions, the accuracy of the second-order analytical solution is validated by comparisons with the numerical predictions. The derivation also provides analytical expressions for channel and wall velocity profiles along the filter length. This study reveals the necessity of considering the nonlinear term of the governing equations when the actual open widths of inlet and outlet channels are quite different.

In-Situ Fabrication of g-C3N4/ZnO Nanocomposites for Photocatalytic Degradation of Methylene Blue: Synthesis Procedure Does Matter

“…To find out the major active species for the photocatalytic oxidation, several scavengers were added in the photocatalytic system individually to trap and remove corresponding active species. It was reported that ammonium oxalate (AO), isopropanol (IPA), and N 2 could act as effective scavengers to holes (h + ), hydroxyl radical (●OH), and superoxide radical (●O 2 − ) [ 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 ]. As shown in Figure 8 , the photodegradation activity of the g-C 3 N 4 /ZnO (0.1:1 CN) sample had a dramatic decrease with the addition of AO and N 2 under light irradiation, suggesting that both holes and ●O 2 − are the main oxidative species in a MB degradation reaction.…”

Theoretical Framework of a Polydisperse Cell Filtration Model

“…ε is the filtration medium porosity. d ci and b i are defined through eqs and , which are consistent with previous work. ,, d pore, i [m] is the pore size of the cell i . The SI base unit is adopted across the present study. The dashed line in Figure is a measured PSD by mercury intrusion (MI), which is a standard technique in characterizing a porous medium.…”

“…Evaluation of m in eq is given by . The notations and variables are consistent with previous publications ,, where it is possible.…”

Experimental Study on a Diesel Particulate Filter with Reciprocating Flow

“…After a long period of operation, the DPF still needs to be disassembled to clean up the residues in the filter. 19−21…”

“…This is due to the fact that several factors need to be concerned; they are the wide range of engine operations, thermal inertia of the DOC and DPF, the complexities of the reactions in the DOC and DPF, and the injection model of the fuel injectors. , In addition, all forms of regeneration can only remove combustible constituents of the PM trapped in the DPF and cannot remove incombustible constituents remaining behind as ash. After a long period of operation, the DPF still needs to be disassembled to clean up the residues in the filter. − …”