The Influence of Channel Structure on the Flow and Heat Transfer Characteristics of Supercritical Aviation Fuel in PCHE

The flow and heat transfer characteristics of aviation fuel RP-3 within three Printed Circuit Heat Exchanger (PCHE) channel structures—straight, zigzag, and airfoil—were numerically investigated. The results indicate that the airfoil PCHE exhibits the best overall heat transfer performance. Further analysis was conducted to study the influence of varying transverse spacing, staggered spacing, and longitudinal spacing on the flow and heat transfer characteristics under different fuel inlet temperatures and mass flow rates within the airfoil channels. The study revealed that, under a single operating condition, increasing transverse and staggered spacing and reducing longitudinal spacing decreased the friction coefficient within the channel. Increasing staggered and longitudinal spacing reduced the convective heat transfer coefficient. Increasing transverse spacing and reducing longitudinal spacing improved the comprehensive evaluation index. When the fuel inlet temperature increased from 373K to 473K, the friction coefficient decreased, the convective heat transfer coefficient initially increased and then decreased, and the comprehensive evaluation index increased. Increasing the transverse spacing can enhance the comprehensive evaluation index by approximately 10.1-10.7. When the fuel inlet mass flow rate increased from 0.296g/s to 0.592g/s, the friction coefficient decreased, and both the convective heat transfer coefficient and the comprehensive evaluation index increased. Increasing the transverse spacing can increase the comprehensive evaluation index by approximately 7.6%-10.8%. The impact of structural parameters on the flow and heat transfer characteristics remained consistent when varying the inlet temperature and mass flow rate.