Transient numerical simulation of thermal oxidation deposition of supercritical RP-3 aviation kerosene in single-side heated rectangular cooling channels

Thermo-oxidative deposition of aviation kerosene represents a critical challenge limiting the long-term safe operation of aero-engine active cooling systems. In this work, a three-dimensional transient numerical framework coupled with dynamic mesh technology was developed for rectangular cooling channels, integrating a six-step thermal oxidative deposition kinetic model. The deposition evolution of supercritical RP-3 kerosene under 3 MPa and single-sided heating was simulated, focusing on the coupled interactions among coke growth, flow redistribution, and heat transfer variation. Results reveal a bimodal deposition pattern governed by distinct mechanisms: the inlet peak is associated with temperature-gradient-driven surface reactions, whereas the outlet peak is dominated by high-temperature oxidation pathways involving deposition precursors. Coke accumulation induces flow passage constriction, enhancing convective heat transfer and partially offsetting deposit thermal resistance, thereby reducing the deposition rate with heating time. Increasing dissolved oxygen concentration accelerates downstream deposition through enhanced precursor formation, while channel aspect ratio regulates deposition by modifying flow and heat transfer characteristics. These findings provide new insights into the transient coupling between deposition evolution and cooling performance, offering guidance for optimizing active cooling channel structures and suppressing thermal oxidative deposition in advanced aero-engines.