Open Access Dissertation
Date of Award
Nabil G. Chalhoub
Frictional losses in internal combustion engines approximately account for 10% of the expended fuel energy. Moreover, forty percent of these losses are attributed to the reciprocating motion of the piston-assembly. Besides the adverse effect of friction on fuel economy, the intricate dynamics of the piston-assembly tend to significantly influence the thermal efficiency through blow-by, the engine durability through wear, and the engine noise through piston-slap. Moreover, 40 to 80% of the lubricant oil consumption has been attributed to the ring-pack dynamics.
In this dissertation, a reliable tool has been developed using MATLAB/SIMULINK and embedded C-S Functions that predicts the intricate dynamics and lubrication regimes of the piston-assembly under various engine operating conditions. The current formulation considers the interconnected motions of the crankshaft, the connecting-rod, the piston (both primary and secondary motions), and the ring-pack using a multi-body dynamic approach. Curved beam Finite Element method for Timoshenko beams was used to account for the longitudinal and in-plane transverse deformations of the rings. Furthermore, the interaction between piston skirt, ring running surface, and the lubricating oil film was included in order to predict hydrodynamic and elasto-hydrodynamic lubrication regimes.
Hakeem, Mohannad, "Intricate dynamics and hydrodynamic frictional losses of the piston-ring assembly in internal combustion engines" (2012). Wayne State University Dissertations. 374.