Term of Award

Summer 2014

Degree Name

Master of Science in Applied Engineering (M.S.A.E.)

Document Type and Release Option

Thesis (open access)


Department of Mechanical Engineering

Committee Chair

Cheng Zhang

Committee Member 1

Aniruddha Mitra

Committee Member 2

Shaowen Xu


In this work, simulations of the combustion reaction within an optical Sandia/Cummins N14 direct-injection compression ignition engine are conducted. First, validation of the spray model against liquid and vapor penetration data was conducted using a trial and error method. Secondly, the overall engine model was validated against pressure and temperature data across high and low temperature combustion regimes. The third phase of the work was focused on creating a combustion model for biodiesel. The fourth and final phase was to test the biodiesel combustion model in the pertinent combustion regimes. The agreement with common trends in emissions of biodiesel combustion models were only verified in a few cases. Negative changes in combustion quality, based on fundamental differences in fuel physical properties, were reflected in the combustion characteristics of biodiesel. The negative effects of biodiesel fuel impingement on the piston and wall, as a result in high viscosity fuel nozzle flows, accurately throttled the combustion process. Overall comparison indicates that the interplay of the spray, collision, breakup, and autoignition models must be further understood to improve the accuracy of predictions.