Supercritical Heat Transfer of Methane in Regenerative Cooling Channels

In order to enhance the efficiency of the supercharged engine’s autonomous regenerative cooling system, the numerical simulation method was used to investigate the flow and heat transfer characteristics of [Formula: see text]. The findings indicate that rectangular channels exhibit superior overall heat transfer capability compared to circular channels of the same hydraulic diameter. The heat transfer performance can improve by increasing the curvature radius of rectangular channels or reducing channel height, but the pressure drop also increases accordingly. The curvature radius increases from 5[Formula: see text] to 7.5[Formula: see text], and the density variations cause a decrease in the Richardson ratio [Formula: see text]. The heat transfer capability at bends results in a 31.25% reduction, while the overall heat transfer capability of the entire section is enhanced by 10.8%. The flow velocity can increase by lowering the channel height, thereby improving heat transfer, but the pressure drop will rise exponentially. When the [Formula: see text] exceeds 10, centrifugal force dominates the process of enhancing heat transfer, while gravity can be ignored. However, when the [Formula: see text] is less than 10, the secondary flow induced by the competition between centrifugal force and gravity plays a crucial role in enhancing heat transfer.