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A new CFD simulation model and methodology for oil jet piston cooling has been developed using the modern level set approach. In contrast to the widely used volume of fluid (VOF) method, the level set approach explicitly tracks the interface surface between oil and air, using an additional field equation. The method has been extensively tested on two- and three-dimensional examples using results from literature for comparison. Furthermore, several applications of oil jet piston cooling on Ford engines have been investigated and demonstrated. For example, three-dimensional simulations of piston cooling nozzle jets on a diesel engine have been calculated and compared to test-rig measurements. Laminar jets, as well as jets with droplets and fully atomized jets, have been simulated using realistic material properties, surface tension, and gravity.

The optimization of the exhaust port shape for best mass flow is an excellent opportunity to improve fuel economy, emissions, and knock sensitivity of internal combustion engines (ICE). This is valid for many different types of combustion systems including gasoline, alcohols, alternative fuels such as compressed natural gas (CNG) or hydrogen, and e-fuels. Nowadays, so-called cylinder-head integrated exhaust manifolds (IEM) guide the exhaust gas from the combustion chamber to the turbocharger. This specific design requires lots of strong bends and turnings of the exhaust ports in very narrow space, since they need to be guided through a labyrinth of bolts, water cores, and oil passages. In fact, this challenges the avoidance of increased pressure drops, reduced mass flow rates, and deterioration of port flow efficiencies. The optimization of the individual port by computational fluid dynamics (CFD) is a proper means to minimize or even eliminate these drawbacks.

Efficient cooling of pistons with oil jets can avoid engine failures due to exceeded piston temperatures of thermally high-loaded combustion engines and can contribute to fuel consumption savings. To reduce expensive and time-consuming engine testing during product development, computational fluid dynamics (CFD) simulations help to quantify the piston cooling performance and provide detailed insights into the complex interactions between oil, air, and piston already in the design phase. The durability of new piston design approaches, such as integrated advanced cooling galleries or highly resistant materials like steel, can be evaluated including the use of alternative fuels, such as compressed natural gas (CNG), hydrogen, alcohols, or e-fuels. A new CFD simulation methodology for oil-jet piston cooling has been developed to investigate the cooling efficiency considering various piston cooling geometries and operational parameters.