Criterion for Heat Transfer Deterioration of Aviation Kerosene under Supercritical Pressures

In order to prevent the heat transfer deterioration phenomenon in thermal protection of aero engine, an experimental investigation on heat transfer of RP-3 aviation kerosene in a vertical upward circular tube under supercritical pressures was conducted.Effects of the operating parameters, including the heat flux, inlet pressure and inlet temperature, on heat transfer deterioration were studied. The characteristics of heat transfer deterioration were explored, and the criterion for initial condition of heat transfer deterioration was obtained. Furthermore, the effects of buoyancy and thermal acceleration on heat transfer deterioration were analyzed. The new determination criterions for buoyancy and thermal acceleration applied to aviation kerosene were established, the heat transfer correlation considering the effects of both was developed. Results indicate that the heat transfer deterioration of aviation kerosene occurs in the condition of Nu/Nu0<0.5, based on which, it is found that the heat transfer deterioration phenomenon appears when the buoyancy factor Bu>1.6×10-6 or the thermal acceleration factor Ac>3.3×10-6. The heat transfer correlation takes into account the effects of buoyancy and thermal acceleration, and has high prediction accuracy. © 2019, Editorial Department of Journal of Propulsion Technology. All right reserved.