Advanced Techniques for Enhancing Engine Efficiency: Knock Phenomena and Piston Cooling Strategies Analysis

This dissertation presents research aimed at decarbonizing the surface transport sector by enhancing the efficiency of internal combustion engines. The studies focused on two major initiatives: understanding knock phenomena in spark ignition engines and developing a CFD model for oil jet impingement in high-performance engine pistons. The first initiative, in collaboration with the Engine Research Center at the University of Wisconsin-Madison, explored a novel knock metric based on ring-down magnitude. A 0D, multi-zone Cantera-reactor model simulated combustion. Experimental pressure data under knocking conditions were collected using a surrogate fuel blend. The model successfully replicated knock events and heat exchange, proving its predictive capability. Further analysis examined transducer mounting effects on knock measurements. Results indicated mounting strategies significantly impact knock quantification, with the ring-down magnitude method providing better consistency. The second initiative, in collaboration with Asso Werke, involved developing a 3D CFD model to simulate oil jets beneath the piston crown. The study assessed oil jet impingement’s effect on heat transfer, internal temperature distribution, and material stress. The model, validated with simplified cases, was extended to complex geometries to determine the heat transfer coefficient. The model's effectiveness is currently under evaluation. This dissertation advances internal combustion engine efficiency through knock analysis and heat transfer modeling, supporting transport sector decarbonization.