Numerical and experimental study on piston multi-physical field heat load of marine engine based on high frequency oscillatory cooling and combustion characteristics

With the increased power density of marine engines, traditional methods of using experimental correlations are no longer adequate. When using experimental methods, conducting multiple experiments is both costly and labor-intensive. This paper proposes a new analytical method based on the high frequency oscillatory cooling and combustion characteristics to calculate the piston temperature and the influence of oscillating cooling on the heat transfer characteristics of the piston. The combustion and cooling side boundary conditions are replaced by conducting cylinder full-process combustion and cooling chamber oscillation calculation analysis. The accuracy of the high frequency oscillatory cooling and combustion model is verified by piston temperature and single-cylinder engine experiment. The results show that compared with the relative movement of cooling oil to the piston, the cooling oil coverage can improve the convective heat transfer of the cooling chamber wall. Moreover, the average error of piston temperature field calculated by coupling method is only 2.08%, which is 34.8% of traditional, and the error fluctuation is only 0.48%, which is 7% of traditional. It shows that compared with traditional method, new method is more accurate in both accuracy and temperature distribution closer to reality. The innovative method delineated effectively solves the enduring challenge associated with inaccurate calculations of piston temperature resulting from using traditional methods, thereby substantially elevating the level of precision in the computational process.