SAE International New Methodology for Transient Engine Rig Experiments for Efficient Parameter Tuning 2013-01-9043

When performing catalyst modeling and parameter tuning it is desirable that the experimental data contain both transient and stationary points and can be generated over a short period of time. Here a method of creating such concentration transients for a full scale engine rig system is presented. The paper describes a valuable approach for changing the composition of engine exhaust gas going to a DOC (or potentially any other device) by conditioning the exhaust gas with an additional upstream DOC and/or SCR. By controlling the urea injection and the DOC bypass a wide range of exhaust compositions, not possible by only controlling the engine, could be achieved. This will improve the possibilities for parameter estimation for the modeling of the DOC. Important features of the resulting data include fast transients in concentrations with only small variations in temperature, CO concentrations with HC concentrations close to zero, and NO concentrations close to zero with significant NO 2 concentration.