Engineering Commons^™

An Experimental Study Of A Passive Nox Adsorber (Pna) For The Reduction Of Cold Start Diesel Emissions, Conor Berndt

Dissertations, Master's Theses and Master's Reports

Medium and heavy-duty diesel engines contribute nearly a third of all NOx emissions nationwide. Further reduction of NOx emissions from medium and heavy-duty diesel engines is needed in order to meet National Ambient Air Quality Standards (NAAQS) for ambient particulate matter and ozone. Current diesel engine aftertreatment systems are very efficient at reducing NOx emissions at exhaust temperatures above 200 °C, however at exhaust temperatures below 200 °C there are significant NOx emissions at the tailpipe. Therefore, a reduction of diesel engine cold start and low speed/load operation emissions, where exhaust temperatures are below 200 °C, is needed. Utilizing a …

Cold Start Analysis And Modeling Of A Direct-Injection Gasoline Engine, Yash Borghate

Dissertations, Master's Theses and Master's Reports

In this thesis, two different works related to cold start of a direct-injection (DI) gasoline engine are shown. First, effect of split injection is studied on engine exhaust temperature and hydrocarbon emissions for cold start conditions. Instead of single injection, two injections are done, one injection during the intake stroke and one injection during the compression stroke. Split injection is known to reduce jet wall wetting, thus reducing the hydrocarbon emissions from engine itself. Further, split injection reduces engine cycle-by-cycle variability with respect to the single injection case. Correlations between start of injection for the injection in the intake stroke …

Improving Startability And Reducing Emissions In Flexfuel Spark Ignition Direct Injection Variable Cam Timing Engine, Vaibhav S. Kale

Dissertations, Master's Theses and Master's Reports - Open

Experimental work and analysis was done to investigate engine startup robustness and emissions of a flex-fuel spark ignition (SI) direct injection (DI) engine. The vaporization and other characteristics of ethanol fuel blends present a challenge at engine startup. Strategies to reduce the enrichment requirements for the first engine startup cycle and emissions for the second and third fired cycle at 25°C ± 1°C engine and intake air temperature were investigated.

Research work was conducted on a single cylinder SIDI engine with gasoline and E85 fuels, to study the effect on first fired cycle of engine startup. Piston configurations that included …