Effect of oxidation deposition by supercritical kerosene on heat transfer in a coiled tube

The deposition in fuel cooling systems remains a challenge to the development of active cooling technologies for air-breathing engines. In this study, we investigated the influence of the secondary flow and heat transfer of a supercritical kerosene in a coiled tube on oxidation deposition both in experimental and numerical methods. The coiled heated tube reactor under the constant heat flux and the flow rate was applied to simulate the heat-exchanger in an aero-engine cooling system. The distributions of dynamic pressure, temperature, velocity and turbulence kinetic energy were studied in a circular cross-section located in the middle of the tube. The microstructure morphology, elements of the deposition, and residual fuel compositions have been measured by SEM, XPS and GC-MS. Secondary flows induced in the coiled tube enhance the heat transfer greatly and slightly increase the deposition rate, resulting in a linear wall temperature profiles and a uniform coking distribution along the tube. The modified heat transfer correlation of the supercritical RP-3 in the coiled tube was fitted at different flow rates and heat fluxes.