Dual-fuel engine crankpin bearings: Tribo-dynamics modeling and telemetry verification

Dual-fuel engines require friction pairs to maintain reliable tribo-dynamics performance operating on natural gas and diesel combustion modes. However, the performance disparities between these two modes remain underexplored due to a scarcity of in-situ data and high-fidelity models. To address this gap, this study establishes a comprehensive nonlinear tribo-dynamics model for the crankpin bearing system of a marine dual-fuel engine, coupling multibody dynamics with mixed lubrication, asperity contact, elastic deformation, and 3D thermal interactions. Another key contribution of this work is the development of a custom in-situ signal processing and telemetry system, which enables the capture of real-time data from a full-scale engine for model validation. In-situ measurements reveal that natural gas operation produces a steeper combustion pressure rise and increases the bearing temperature at CP1 by 4.74 °C relative to diesel operation. The validated model achieves a mean thermal prediction error below 1.0 °C. The simulation further shows that natural gas operation raises peak hydrodynamic pressure from about 47 MPa to 60 MPa, reduces the minimum oil film thickness, and increases the peak oil film temperature. The combined effect of intensified loading and non-uniform structural stiffness shifts the edge-contact risk toward the axial edge of the upper bearing bush. These results clarify the mechanism by which natural gas combustion intensifies bearing mixed-lubrication risk and provide design and monitoring guidance for profile optimization, local stiffness compensation, and telemetry-based condition assessment in low-carbon marine engines.