3D Virtual Simulations of Crankcase Dynamics for Oil Pan Aeration Analysis

This research employs sophisticated Unsteady Reynolds-Averaged Navier-Stokes (URANS) simulations to dissect the transient multiphase flow dynamics within a four-cylinder inline (I-4) engine, with a particular emphasis on gas-liquid interface interactions and oil distribution phenomena. Utilizing a commercial three-dimensional Computational Fluid Dynamics (CFD) software suite, the study integrates detailed crankshaft rotational kinematics and pistonic reciprocation to accurately model oil drawdown and holdup behavior across varying operational regimes. A Volume of Fluid (VoF) methodology is employed to evaluate the effects of crankshaft rotational speeds of 5000 rpm and 6500 rpm on oil distribution and aeration within the oil pan. Comprehensive computational analyses are conducted to characterize oil-air distribution patterns, quantify oil flow rates through drainback pipes, and elucidate bubble formation dynamics within the sump. The study further analyzes the relative contributions of crankshaft rotation, piston pumping, and balance shaft gear motions to the aeration levels in the sump. Additionally, the impact of two distinct windage plate designs on oil management and aeration is assessed through a detailed design evaluation. The computational predictions are compared against experimental data, to understand the predictions accuracy and reliability. This work provides a sophisticated three-dimensional computational framework that can significantly advance the understanding of crankcase oil dynamics and aeration performance, serving as a critical tool for optimizing engine design and enhancing conventional testing methodologies.