Study on enhanced flow and heat transfer characteristics in regenerative cooling channels with conical ribs using supercritical hydrogen

ABSTRACT To address the thermal protection challenges in the combustion chamber of hydrogen-fueled rocket engines, a regenerative cooling channel with conical ribs was proposed and compared with a smooth channel. A numerical study was conducted to investigate the effects of the Reynolds number and rib spacing on both the pressure drop and thermal performance of a cooling channel with conical ribs. The study further explored how these parameters influence the relative heat transfer enhancement capability of the conical ribs, and analyzed the effect of heat flux on the heat transfer characteristics of the conical rib cooling channel. Results show that conical ribs significantly improve thermal performance compared to the smooth channel, with only a marginal pressure drop penalty. Reducing the rib spacing and increasing the Reynolds number maximally decreased the wall temperature of the conical rib channel by 8.15% while improving its thermal-hydraulic performance by 15.60%. The relative heat transfer enhancement capability of the conical ribs diminished as the rib spacing and Reynolds number increased. Increasing the heat flux weakened the thermal performance of the conical rib channel.