Analysis of temperature field and thermo-mechanical coupling of oscillating cooling piston

Abstract

In order to analyze the cooling effect of the internal cooling oil gallery on the piston, the temperature field and stress-strain distribution law of the oscillating cooling piston under thermal load, mechanical load and thermo-mechanical coupling were studied. The VOF(volume of fluid) multiphase flow model and dynamic mesh technology were used to simulate the oscillatory heat transfer process of the oil in the internal cooling oil gallery of the piston, and the heat transfer coefficient of oscillating cooling oil gallery was obtained. The data were mapped to the solid surface of the piston. The piston was loaded with thermal load, mechanical load and thermo-mechanical coupling load, respectively, to analyze the temperature field changes of the piston before and after using oscillating cooling oil gallery, and the distribution laws of thermal stress, mechanical stress and coupling stress of the piston before and after using oscillating cooling oil gallery were compared and analyzed. The results show that the temperature in each region of the piston decreases to different degrees after oscillating cooling, with the highest temperature of the piston decreasing by 75%; The maximum stress of the piston under the thermo-mechanical coupling action is less than the sum of the results of the two separate effects; After oscillating cooling, the thermal stress and coupling stress of the piston also decrease in some degrees. The stress distribution law of piston before and after cooling in the internal cooling gallery is obtained, which provides some theoretical reference for the optimization design of the internal cooling oil gallery of the piston.

Keywords

• internal combustion engine engineering; oscillating cooling piston; cooling oil gallery; thermal stress; mechanical stress; coupling stress