Reliability is critical in high-power density engines, where components operate under extreme conditions to achieve optimal performance. These demanding conditions give rise to complex multiphysics and multiscale interfacial phenomena, contributing to early wear stages, poor performance, and catastrophic engine failure due to severe mixed lubrication, cavitation damage, fatigue, and overheating effects. Therefore, enhancing the durability of such engines is paramount. This study investigates cavitation erosion in high-power density engines, with a particular focus on the connecting rod journal bearing. A novel multiscale cavitation erosion (MCE) model is presented, integrated with a mixed-elastohydrodynamic lubrication simulation framework. Realistic boundary conditions for bearing load, oil supply hole position, and pressure are obtained from a multibody dynamic simulation analysis of the entire system. The proposed multiscale cavitation erosion model predicts the cavitation damage energy at each computational mesh node within the macroscopic bearing domain. This energy serves as a threshold to erode the corresponding microscale area surrounding the macroscale node region. The equivalent microscale area is then coupled with the bearing surface topography, and material removal is simulated using a novel cavitation erosion algorithm. The proposed model is applied to evaluate the evolution of cavitation damage in the connecting rod bearing of a motorsport engine. The analysis considers various influencing factors, including engine speed, bearing clearance, lubricant formulation, and oil temperature. The findings reveal key insights into the cavitation erosion mechanisms, highlighting the significant influence of lubricant formulation and engine speed on erosion severity in the studied bearing.

Durability and reliability have been studied for decades through intensive trial-error experimentation. However, there are numerous fields of application where the costs associated with this approach are not acceptable. In lubricated machines with severe dynamic loads, such as high-power-density engines, simulation tools offer clear advantages over intensive testing. Prototypes and multiple scenarios can be cost-effectively simulated to assess different lubricants and engine configurations. The work presented here details the study of wear based on a validated elastohydrodynamic (EHD) simulation model of the connecting rod journal bearing. This model accounts for elastic deformation through a connecting rod finite element model (FEM). In addition, multiple lubricant rheological and tribological dependences, determined by specific experimental tests, are applied in the model through their interaction with the simulation software. Correspondingly, a novel wear algorithm is proposed to predict wear depth over time evolution along a proposed wear cycle based on the typical working ranges of high-performance engines. A final assessment is presented to compare 4 different ultralow-viscosity lubricants in their protective performance under severe conditions. The results show the evolution of the wear load and wear depth over the wear cycle. This evaluation is key to describing a lubricant selection procedure for high-power-density engines.