Implementing the Effect of ANR Non-Uniformity on Transient SCR Performance through 3D-1D Coupling
Apoorv Kalyankar, Cummins
Implementing the Effect of ANR Non-Uniformity on Transient SCR Performance through Coupling between 3D Spray Analysis and 1D Kinetic Modeling
Selective catalytic reduction is a promising technology for meeting the stringent requirements pertaining to diesel emissions. One of the most important requirements to achieve high DeNOx performance is to have a high uniformity index (UI) of Ammonia to NOx Ratio (ANR) at the catalyst inlet. Steady State 3D CFD models are frequently used for predicting ANR UI values but are not feasible for running a transient cycle like FTP. On the other hand, 1D kinetic models run in real time and can predict SCR transient performance but do not typically capture the effect of non-axial non-uniformities. In this work, we have developed a methodology to combine the two methods to be able to predict transient SCR performance, taking the effect of ANR non-uniformity into account in 1-D simulations. We will discuss the modeling approach, analysis tools used and validation of the method against on-engine data for typical aftertreatment configurations. We will also discuss the correlation between DeNOx performance and a proposed weighted UI for transient cycles.