Access Type

Open Access Dissertation

Date of Award

January 2015

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Mechanical Engineering

First Advisor

Marcis Jansons

Abstract

In response to increasingly stringent engine emissions regulation, three dimensional in-cylinder combustion modeling is increasingly being used as a tool to optimize the combustion process and reduce the cost of experimental testing. Due to the complexity of the physical and chemical interactions involved in the in-cylinder combustion process, the engine combustion model consists of numerous sub-models developed under pre-defined initial and boundary conditions requiring further model calibration depending on different engine applications. Fuel surrogates, one of those sub-models developed for different combustion applications, may not capture all the behavior when applied to the varying temperature-pressure conditions present in a compression ignition engine.

In this work a set of optical and global measurements are chosen to experimentally validate a fuel surrogate using an optically accessible compression ignition engine. In addition, to provide a means of directly comparing three-dimensional engine combustion CFD predictions to in-

cylinder optical measurements, another aim of this work is to model light emission during the compression ignition engine combustion process. Major excited state species (CH*, CH2O*, OH*, CO2* and C2*) are modeled to study UV chemiluminescence signal observed in the in-cylinder hydrocarbon fuel oxidation process. A novel approach to validate multi-dimensional combustion CFD results is presented. The classic two-color method theory is further developed by analysis of the natural soot luminosity on a McKenna Flat Flame Burner. Spectral and Coherent anti-Stokes Raman Spectroscopy (CARS) measurements are used to propose a value of α in the soot emissivity model.

Download

Share

COinS