Numerical study of the influence of wetting properties on flow characteristics and heat transfer in piston cooling gallery

Abstract

Being a crucial thermal management component in an internal combustion engine, the wettability of the piston gallery significantly influences heat transfer performance. This study deeply investigates the impact of the piston gallery’s wettability on heat transfer performance through numerical simulation. Adjusting the wettability parameter, specifically the contact angle, resulted in the observation of varied droplet patterns on the surface of gallery. Surface wettability directly influences oil distribution and adhesion on the piston surface, consequently impacting the piston’s cooling effectiveness. Optimizing the wettability of the oil cavity is expected to improve the cooling efficiency of the piston, contributing to an overall performance improvement. The numerical study revealed that a surface with a certain degree of hydrophilicity facilitates uniform droplet distribution on the surface of the gallery, forming a film-like oil droplet. Such a film of oil droplets effectively enhances heat transfer efficiency, with a well-wetted surface promoting effective contact between the oil and piston surface for more efficient heat transfer. Conversely, a highly hydrophobic surface leads to droplet self-aggregation in the gallery, hindering effective heat dissipation from the piston. Poor wettability prevents uniform oil adhesion to the piston surface, resulting in decreased heat transfer efficiency. To summarize, the wettability of the piston gallery significantly influences heat transfer performance. Optimizing surface wettability enhances piston cooling, thereby improving overall internal combustion engine performance.