One-dimensional Catalyst Modeling and its Application to Urea SCR Devices
Christopher Depcik, The University of Michigan
As government regulatory agencies continue to decrease the tolerance level for problematic emissions, there is an overwhelming need to model aftertreatment devices in order to optimize their control and on-board placement. This is because experimental tests alone cannot solve the problem due to cost and time-constraints. In this talk, a brief history of one-dimensional catalyst modeling is presented to illustrate the pertinent processes that occur within the catalyst. Based on the appropriate source terms, a catalyst model was derived from the Euler equations of motion and expanded to account for an insulating layer and energy generation within the catalyst. Fast numerical solvers are described to allow for efficient numerical computation of all of the models including transient terms. A general framework was created in order to model any type of aftertreatment device. It was then used to simulate a Urea SCR device over a complete FTP-75 emission regulatory test.