New Approach to Washcoat Diffusion Resistance
Edward Bissett, Gamma Technologies
Here we demonstrate a new approach to capture the principal effect of washcoat pore diffusion resistance in monolithic aftertreatment reactors. Our solution obtains the concentration distribution within the washcoat analytically using established asymptotic methods for the governing reaction-diffusion equations without ad hoc approximation of either the reactions or transport. There is no computational burden associated with the extra dimension through the washcoat. The reaction rates are used in their full nonlinear complexity that we routinely accept when evaluating at the washcoat surface concentrations in the absence of washcoat pore diffusion resistance. Coverages and dual reaction schemes in two washcoat layers may be included. For single-layer washcoats, computational times are similar to the corresponding case of no diffusion resistance.