Mechanical Engineering Commons^™

Design And Implementation Of An Oxidation Catalyst For A Spark Ignited Two Stroke Snowmobile Engine, Noah Squires

Dissertations, Master's Theses and Master's Reports

Spark ignited two stroke engines are under increasing pressure as emissions standards become stricter, making them a perfect candidate for a catalytic aftertreatment system. Yet several significant challenges to catalysis exist. Namely two stroke exhaust systems are very sensitive to back pressure changes and high emissions concentrations can make controlling the temperature of the catalytic reaction difficult. Therefore, it is imperative that a two stroke specific catalyst design process be developed. This project focused on beginning to develop such a design process. Key results of this work include finding a location for the catalyst in the exhaust system that offers …

Development Of A 2d Scr Catalyst On A Diesel Particulate Filter Model For Design And Control Applications To A Ultra Low Nox Aftertreatment System, Venkata Chundru

Dissertations, Master's Theses and Master's Reports

This research focuses on modeling and control of PM and NO_x in diesel engine exhaust using an SCR catalyst on a Diesel Particulate Filter (SCR-F). A 2D SCR-F model was developed that is capable of predicting internal states: 2D temperature, PM and NH₃storage distributions and filtration efficiency, pressure drop, PM mass retained in the PM cake and substrate wall and outlet NO, NO₂and NH₃concentrations. The SCR-F model was used to simulate a DOC + SCR-F + DOC + SCR ultra-low NOx system that can achieve > 99.5% NOx conversion efficiency.

The model was calibrated …

Incorporation Of Higher Carbon Number Alcohols In Gasoline Blends For Application In Spark-Ignition Engines, Kristina Lawyer

Dissertations, Master's Theses and Master's Reports

The 2007 U.S. Renewable Fuel Standard (RFS2) requires an increase in the use of advanced biofuels up to 36 billion gallons by 2022. Higher carbon number alcohols, in addition to cellulosic ethanol and synthetic biofuels, could be used to meet this demand while adhering to the RFS2 corn-based ethanol limitation. Alcohols of carbon numbers 2 through 8 are chosen based on their chemical and engine-related properties.

Blend comparison metrics are developed from automotive industry trends, consumer expectations, U.S. fuel legislation, and engine requirements. The metrics are then used to create scenarios by which to compare higher alcohol fuel blends to …