Maximizing Lubricant Life for Internal Combustion Engines

Abstract

Although the lubrication systems for internal combustion engines have been designed to prevent engine wear and friction, their configuration does not contemplate the maximum use of each load of lubricant; because of this limitation, lubricant consumption is currently an environmental and economic problem. In this work, the performance of lubrication systems to form the tribological film that prevents wear is simulated and optimized, through the mass balance of the lubricant precursors contained in the oil and the implementation of optimal control techniques. Optimization results indicate that regulating the flow of lubricant passing through the engine prevents excessive degradation of lubricant precursors, maximizing the life of each lube oil charge, giving the possibility to increase the sustainability of internal combustion engines.

Studies on Engine Oil Degradation Characteristics in a Field Test with Passenger Cars

“…As friction losses form about 11.5% of fuel energy in engines of typical passenger cars [5], lubrication of the contacting surfaces in the major engine subsystems will continue to represent a significant goal for the development of low-friction base engines [6]. Although the lubrication process that occurs within the lubrication systems is quite complex, and even today there is not a complete understanding from the mechanical and physicochemical point of view [7], there are studies on lubrication models for IC engines in order to investigate the friction, wear, and tribofilm formation on surfaces of moving parts, as well as the predicted lubricant life for conventional lubrication systems [8,9].…”

Friction Coefficient Dynamics of Tribological Coatings from Engine Lubricants: Analysis and Interpretation

“…Even today, there is not a complete understanding of the phenomena that occur during the operation of these lubrication systems from mechanical and physicochemical perspectives. Additionally, a multidisciplinary research perspective is required due to the diversity in the nature of the phenomena produced in the lubricating process [9].…”

“…Measurements of film thickness are commonly carried out by spacer layer interferometry and electrical contact resistance methods for in situ measurements, and atomic force microscopy, scanning electron microscopy, and transmission electron microscopy for ex situ measurements [18,22,23]. The predictions of the lubricating film thickness are developed from tribochemical models of film growth, experimental parameters of film removal, elastoplastic models of viscous films over rough surfaces, the Reynolds equation, and mass balance models [9,10,17,20,24,25]; the measurements of the coefficient of friction are in general carried out from tribological devices that measure friction force [6,13,22,[26][27][28][29]. Friction coefficient predictions are developed from multi-scale roughness and linear models of friction as a function of coated surfaces [2,29,30].…”