TEMPERATURE STRATIFICATION SIMULATION OF MIXING HEAT TRANSFER IN SPACE KEROSENE STORAGE TANK

Temperature stratification in the process of mixing heat transfer of space kerosene is harmful to the safe and efficient operation of rocket launch. Aiming at the mechanism and control measures of temperature stratification, a three-dimensional transient two-phase flow model for space kerosene cooling is established by using volume of fluid (VOF) method with consideration of the variable physical properties of kerosene. The accuracy of the model is verified by experiment, and the simulation results of average temperature are highly consistent with the zero-dimensional model. By taking the mass-weighted average temperature gradient as the evaluation index, the effects of different operations and geometric conditions on the temperature stratification of kerosene mixing heat transfer are studied by sensitivity analysis and orthogonal test. The results show that enhancing the convective heat transfer inside the kerosene storage tank is the fundamental method to weaken the temperature stratification. The higher flow rate of the inlet cold kerosene and the fewer nozzles and/or the smaller nozzle diameter is helpful to more efficient mixing, while the more spray nozzles lead to the smaller spray velocity and the smaller spray depth. At the same time, shortcut flow inside the tank should be avoided by proper configuration between the inlet and the outlet.