Numerical simulation of convective heat transfer characteristics of aviation kerosene inside elliptical tubes under supercritical pressure

Heat transfer characteristics of aviation kerosene were investigated numerically using a three-dimensional model. The influence of the ratio of longer axis to short axis of elliptical tubes (r), inlet Reynolds number (Re), and pressure (P) of kerosene on local heat transfer characteristics were discussed in detail. The results indicate that the heat transfer coefficient (h), wall temperature (T-w), and bulk fluid temperature (T-b) increase along Z axis direction from inlet to outlet when P=4Mpa. h increases with increasing r and Re, while T-w decreases with increasing Re and r. T-b decreases with increasing Re and remains stable for a varying r. For P=3Mpa, the deterioration of heat transfer occurs near the outlet of computational geometry, where the temperature of near wall region fluid exceeds the critical point and specific heat decrease dramatically. A correlation for heat transfer coefficient of aviation kerosene at supercritical pressure inside elliptical tubes is proposed and compared with the present simulation data. It is shown that this correlation can predict the simulation data within an +/-15% error band. Compared with circular tubes, elliptical tubes can enhance the heat transfer effect and decrease the wall temperature, thus enhance the security of the operating system.