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Selective Catalytic Reduction (SCR) is effective over a wide temperature window to reduce NOx emissions from engine exhaust during lean operations. In this study, different supplier SCR catalysts are investigated and modeled. A global Ammonia SCR reaction mechanism has been used, and kinetic parameters for selective catalytic reduction of NOx by Ammonia were developed for both Copper (Cu)-zeolite and Iron (Fe)-zeolite SCR catalysts. The kinetic analysis was performed using a commercial one dimensional (1-D) aftertreatment code, coupled with an optimizer. The optimized kinetics have been validated extensively with laboratory reactor data for various operating conditions on three supplier catalysts - two Copper and one Iron based formulations. Both steady state and transient tests are performed and the developed SCR models are shown to agree with the experimental measurements reasonably well.

A one-dimensional engine model was developed for a 4.9-liter V-configuration 6-cylinder turbocharged direction-injection diesel engine. The engine model was first calibrated using the experimental data taken on dynamometer at eight steady-state engine operating conditions. Then the model was extensively validated with four transient dynamometer tests that were conducted mainly with step changes in the engine load, the EGR valve position, the intake throttle position, and/or the VGT vane position. It is shown that the developed model predicts the engine performance and gas dynamics with an error less than 3% in general, both at steady-state and transient engine operating conditions. The validated engine model is very useful in several future applications, such as engine development and optimization, and engine and aftertreatment system integration.