Date of Graduation


Document Type


Degree Type



Statler College of Engineering and Mineral Resources


Mechanical and Aerospace Engineering

Committee Chair

Mridul Gautam.


Engine manufactures have relied on over designed of engines and performance testing to ensure product reliability. The efforts to maximize efficiency and to predict performance characteristics have evoked an interest to study the in-cylinder pressure throughout the respective duty cycle. The duty cycle of an engine is defined as the history of speed and load conditions over which the engine operates in a specific application. Understanding the transient on-road diesel engine duty cycles has been one of major goals for the engine developers. To date there have not been any research performed to identify a wide variety of on-road diesel engine duty cycles. One of the world largest diesel engine manufactures, Cummins Inc., had interest in developing and understanding how the effective life of a diesel engine component is related to its duty cycle. West Virginia University Engine and Emissions Research Laboratory (EERL) was commissioned to conduct this study.;The objective of this study is to create a mathematical model that predicts the effective life of diesel engine components with respect to its operational duty cycle. In particular, power cylinder components were considered along with the variations of in-cylinder pressure. Four different duty cycles were evaluated in this study: a concrete mixer, heavy hauler, dump truck, and a transit bus. In-cylinder pressure data for all four duty cycles were statistically analyzed using the tools from non-parametric function and regression analysis. A mathematical model that predicts the power cylinder component lives was created. Mimicking the infield operation, heavy hauler displays the minimum power cylinder component life, while concrete mixer has the maximum life. Ultimately, this mathematical model will enable the engine manufactures to produce more cost effective components for different duty cycle applications, while fulfilling the customer requirements.