Date of Award


Degree Name

Master of Science


Mechanical and Aerospace Engineering

First Advisor

Dr. Claudia Fajardo

Second Advisor

Dr. Bade Shrestha

Third Advisor

Dr. Christopher Cho


Availability, IC SI engines, thermodynamics, emissions, energy

Access Setting

Masters Thesis-Open Access


The second law of thermodynamics is a powerful tool for calculating the amount of energy that can be converted to work (i.e., the exergy or availability of a system), which cannot be predicted using the first law. The objectives of this research project are to quantify the availability during the compression, combustion and expansion processes of a spark-ignited engine fueled with methane; and to highlight differences in the thermo-mechanical availability of the ideal and spark-ignition (SI) engine cycles. A cooperative single-cylinder research engine was used to measure the data required for availability analysis at equivalence ratios ranging between 0.83 and 1.25. The thermo-mechanical availability, normalized by the energy content of the mixture, was found to increase as the equivalence ratio decreases. First and second-law of Thermodynamics efficiencies also increased for fuel-leaner mixtures, but remained within four percent of each other for methane in both the ideal and the SI engine cycles.