The oscillating cooling process of oil in the oil cooling gallery of highly-intensified piston was simulated numerically and the effective speed was defined. Through the post processing of data

the distributions of field parameters of oil cooling gallery wall in time and space were obtained

and the connection between wall surface heat transfer coefficient and the field synergy performance was analyzed. The results show that: the field synergy performance is good enough in the space range of 60 degree to 120 degree and 240 degree to 300 degree. Distribution rules of effective speed match well with the field synergy angle cosine value; uniform distributions of surface heat transfer coefficients of oil cooling gallery wall are in accord with the distributions of synergy angle cosine value and effective speed

illustrating that field synergy mechanism can explain the convective heat transfer rules of oil oscillating cooling.