In-Situ Investigation of the Interaction Between Surface Metal and Aeroengine Fuel RP-3 in Thermal Oxidation Deposition

During the cooling process, some components of jet fuel react with oxygen dissolved in the fluid, resulting in thermal oxidation deposition. Here, we used a novel in-situ flow experimental system to achieve the decoupling of the intricate oxidation deposition reaction flow process within the pipeline and to investigate the interaction mechanism between fluid-dissolved metal and jet fuel during oxidation deposition. Experimental results indicated that when the surface roughness doubled, the content and distribution area of surface-active metals increased by 20-fold and the deposition amount increased significantly by 339.31%. The substantial proliferation of metal active sites accelerated thermal oxidation deposition, inducing changes in both deposit morphology and internal composition. At 450°C, a notable augmentation of active metal content in RP-3—the main fuel of aeroengines in China—appeared after the thermal oxidation deposition. The temperature effect intensified the interaction process between surface metals and fuel, leading to more severe surface deposition. This study provides guidance into the mechanistic linkages between metal-surface characteristics, temperature, and jet fuel oxidation deposition, which serves as a theoretical foundation for the subsequent design and maintenance of the aeroengine cooling system.