Researcher: Yutaka Oda
Affiliation: Associate professor, Faculty of Engineering Science, Kansai University
 

Abstract: In reciprocating internal combustion engines, such as automobile engines, 20 to 30% of the thermal energy generated by fuel combustion is lost as cooling heat loss. Cooling heat loss is the fraction of thermal energy transferred to the coolant through the wall, and must be minimized to improve engine thermal efficiency since it does not contribute to engine output. In this study, the complex flow and thermal fields in the engine cylinder caused by the reciprocating motion of the piston is modeled as "pulsating turbulent flow with strong repetitive acceleration/deceleration and wall heat transfer." Highly accurate turbulence simulation method was applied to clarify the mechanism of wall heat transfer in the pulsating turbulent flow. We believe that, through such simulations, clarifying the limitations of heat transfer models widely used in current design processes will contribute to the development of advanced models that can predict heat loss with higher accuracy.