Study on Thermal Stratification and Heat Transfer Characteristics in a Fuel Tank of Hypersonic Vehicles

This research presents numerical and experimental investigations of thermal stratification occurring in the fuel tank of a hypersonic vehicle. The effects of heating power on the stability, intensity, development rate, and heat distribution characteristics of thermal stratification in the water tank are evaluated. The Richardson number, Stratification number, penetration time, and thermal stratification energy ratio are used for this evaluation. Additionally, the field synergy principle is introduced to reveal the flow and heat transfer mechanisms. The numerical model is in good agreement with the experimental results at different heating powers. It is observed that the stability and intensity of thermal stratification exhibit a rapid increase initially and then tend to stabilize gradually with increased heating time. Higher heating power enhances the development rate and stability and alters the heat distribution characteristics of the thermal stratification. Moreover, heat transfer is primarily dominated by heat conduction in the vicinity of the wall and top region of the fuel tank. In contrast, the bottom region is characterized by an unsteady alternating distribution of heat conduction and convection, where the range of heat conduction is more extensive. Finally, the experiment demonstrates that the phenomenon of thermal stratification within the fuel tank is more pronounced.