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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.

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.