Optimizing prechamber design and engine calibration for non-quiescent lean-burn gas engines through 0/1D predictive combustion and emissions models

Lean-burn gas operation is essential for meeting strict nitrogen oxides (NOx) emissions regulations and reducing fuel consumption in marine and power generation engines. Because efficient lean combustion requires high-energy ignition sources, the active Pre-Combustion Chamber (PCC) is universally recognized as the optimal solution for large-bore applications. To accelerate engine development and drastically reduce experimental burdens, accurately modelling these complex combustion dynamics using computationally efficient Zero/One-Dimensional (0D/1D) predictive tools is now a critical requirement. To address this challenge, this study presents a comprehensive 0D/1D predictive simulation platform developed in GT-SUITE, tailored to co-optimize PCC geometry, in-cylinder flow motion, and engine calibration for lean-burn gas engines. The framework integrates advanced phenomenological models for predictive combustion, as well as for NOx and unburnt hydrocarbons (HC) emissions. Its predictive capabilities were rigorously validated against an extensive experimental dataset encompassing two distinct pre-chamber designs, demonstrating excellent agreement. Furthermore, the inclusion of a 0D turbulence model guaranteed high-fidelity resolution of flow-combustion interactions, enabling the precise analysis of both quiescent and non-quiescent combustion systems. Serving as a highly efficient computational alternative to demanding Three-Dimensional Computational Fluid Dynamics (3D-CFD) campaigns, the validated framework was leveraged to systematically determine the optimal synergistic configuration of PCC architecture, in-cylinder flow motion, and engine calibration. The optimization analysis demonstrated that the configuration obtained for swirl motion provided the greatest overall benefits, delivering a +1.6% increase in indicated thermal efficiency at full load and minimized unburned HC emissions by -600 ppm at low load.