Theses and Dissertations

Issuing Body

Mississippi State University


Srinivasan, K. Kalyn

Committee Member

Chamra, M. Louay

Committee Member

Mago, Pedro

Date of Degree


Document Type

Graduate Thesis - Open Access


Mechanical Engineering

Degree Name

Master of Science


James Worth Bagley College of Engineering


Department of Mechanical Engineering


A zero dimensional single zone model was developed to determine the crank resoled heat release rate at various injection timings (15°-60° BTDC) and the associated uncertainties from a pilot ignited natural gas engine. The uncertainty analysis examines the percentage contribution from various sources of error, including cylinder pressure measurements, intake manifold pressure measurements, and the impact of assumptions such as constant versus temperature dependent specific heat ratios. In particular, uncertainty percentage contributions and uncertainty magnification factors were used to quantify and compare the uncertainties in heat release rates using temperature dependent specific heat ratio correlations to constant specific heat ratio assumption. It is demonstrated that the error associated with the constant specific heat ratio assumption contributes to about 40 percent error (full scale value) in the net heat release estimates in comparison to using temperature dependent specific heat ratio correlations.