Design Optimization of an Automotive Turbocharger Thrust Bearing Using a CFD-Based THD Computational Approach†
AbstractIn a quest to reduce fuel consumption and emissions of automotive combustion engines, friction losses from many different sources need to be minimized. For modern designs of turbochargers commonly used in the automotive industry, reduction of friction losses results in better efficiency and also contributes to a faster transient response. The thrust bearing is one of the main contributors to the mechanical losses of a turbocharger. Therefore, it is crucial to optimize the design of the thrust bearing so that it has minimum friction losses while keeping sufficient thrust carrying capacity. One of the main challenges of turbocharger thrust bearing design, is that rotation speed is not fixed: the turbocharger may have a rotation speed which varies between 0 to as much as 250 kRPM. Moreover, the thrust bearing generates considerable heat, which changes the temperature of the oil film and its surroundings. In the present work, the design of the thrust bearing of an automotive turbocharger has been optimized. A CFD-based Thermohydrodynamic (THD) computational approach has been developed, taking into consideration heat dissipation, conjugate heat transfer throughout the bearing domain including the surrounding parts, as well as shear thinning and cavitation in the lubricant domain. An optimizer has been coupled to the CFD solver, with the aim of identifying bearing designs with reduced friction losses. Two bearing concepts have been evaluated: a taper-land design—which is a commonly applied thrust bearing concept—as well as a pocket bearing design. The resulting optimum pocket designs exhibit improved performance, in comparison to the optimum taper-land design. The present results indicate that (a) the pocket design concept can substantially contribute to further reducing the friction losses of a turbocharger, and (b) optimal design parameters of pocket bearings depend on the specific application (size, operating conditions), therefore detailed calculations should be performed to verify optimum performance. View Full-Text
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Charitopoulos, A.G.; Visser, R.; Eling, R.; Papadopoulos, C.I. Design Optimization of an Automotive Turbocharger Thrust Bearing Using a CFD-Based THD Computational Approach. Lubricants 2018, 6, 21.
Charitopoulos AG, Visser R, Eling R, Papadopoulos CI. Design Optimization of an Automotive Turbocharger Thrust Bearing Using a CFD-Based THD Computational Approach. Lubricants. 2018; 6(1):21.Chicago/Turabian Style
Charitopoulos, Anastassios G.; Visser, Roel; Eling, Rob; Papadopoulos, Christos I. 2018. "Design Optimization of an Automotive Turbocharger Thrust Bearing Using a CFD-Based THD Computational Approach." Lubricants 6, no. 1: 21.
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