Oil Flow Simulations in the Lubrication System of a Turbocharger

Abstract

Oil sealing in a turbocharger is a key design challenge. Under certain engine operating conditions oil in the lubrication system is likely to enter the compressor or turbine wheel crossing the piston rings which are used to arrest the undesirable oil flow. Compressor side oil leakage can cause white smoke and particulate emissions. Limited experimental and analytical methods are available to aid the designers in developing the oil flow path. The oil flow path has dimensions of the order of a few microns in certain areas and in mm in other areas. In addition, the flow is comprised of oil and exhaust gas mixture in certain regions. The combined effects of disparate geometric length scales and two-phase flow adds to the complexity of the flow. Understanding the oil flow allows the designer to correctly size the components, flow path and also specify the appropriate clearances between for instance shaft and bearing journals. In this study a Computational Fluid Dynamics (CFD) Model has been built and validated through several experiments conducted particularly to check the oil leak through the piston rings. The study shows that CFD based models can predict within engineering accuracy the flow through leakages in a turbocharger. The importance of manufacturing tolerances on the leakages is also highlighted.

Research on Oil Mist Leakage of Bearing in Hydropower Station: A Review

“…Some effective methods for bearing oil mist leakage proof have been explored in engineering practice for nearly a century. The advances in numerical simulation technology in the past three decades have been crucial in studying the effects and mechanism of this phenomenon [31,32], resulting in bearing designs of excellent performance [33][34][35]. To back up their claims, some scholars have combined numerical methods with experiments [36,37], but the drawbacks include the high cost of the equipment and labor-intensive analysis.…”

Investigation on Sealing Performance and Power Consumption of a Novel Centrifugal Pump Type Oil Flinger for Turbocharger

“…They designed a novel labyrinth sealing structure based on the simulation analysis of the flow characteristics of leakage flow inside turbocharger, which reduced the leakage flow by 19%. Moreover, the flow path, the flow characteristics and the pressure distribution of leakage flow in sealing structure were deeply studied by Ramachandran et al relying on the constructed oil phase and oil and air two-phase turbocharger models [17]. The mutual authentication of simulation and experiment demonstrated that the simulation approach was able to predict the leakage flow within engineering accuracy and guided the design of low-leakage turbocharger.…”