| Sloshing in the cryogenic tanks occurs in the processes of land transportation and marine storage,which leads to the sharp loss of tank pressure and the disturbance of thermodynamic equilibrium in the tank.Moreover,sloshing will also bring potential safety hazard due to the shock on the maintenance structure.As a result,it is of great engineering significance to clarify the sloshing mechanism and carry out the sloshing suppression of the liquid in the tank.Research on sloshing characteristics of liquid at room temperature has been conducted widely.However,the physical properties of cryogenic fluid are quite different from those of common liquid.Therefore,previous conclusions on liquid sloshing at normal temperature cannot be simply extended to cryogenic situation.In addition,the evaporation of liquid in the tank should be taken into account,and the influence on the gasliquid interface behavior remains to be studied.In this paper,liquid oxygen is used as the working medium to simulate the sloshing process of cryogenic fluid.The following work is done:(1)The numerical model of liquid oxygen sloshing in tank is established,and the influence of drag force between gas and liquid phase on the changing law of phase interface is considered.The numerical simulation results show good agreement with experimental data in other literature,verifying the correctness of the CFD model.On this basis,the evolution law of the gas-liquid interface in the tank under the condition of free shaking are obtained.The numerical simulation of sloshing and evaporation is carried out for a liquid oxygen tank with thermal stratification,the dissolution process of thermal stratification phenomenon under sloshing condition is obtained,the phenomenon of rapid pressure loss in the tank during initial shaking is observed,and the dynamic evaporation rate within is obtained.(2)Research on the inhibition of sloshing in the liquid oxygen tank is carried out.Through analyzing the flow pattern diagram and the change of liquid mass center position,the suppression effect of different types and parameters of baffles on liquid tanks with various filling rates is evaluated.The results show that within the range of liquid filling rate of 50%-90%,with the decrease of liquid filling rate,the shaking degree caused by radial excitation sloshing becomes more intense.The T-shaped baffle has better anti-shaking effect,and the height of the baffle is optimized.(3)The stress on the inner wall of the liquid oxygen tank under rolling state is studied.The change law of the impact force on the inner wall of the tank varying with time is calculated and analyzed.On this basis,the change of the impact force on the liquid tank varying with time after adding the baffle is studied,and compared with the situation without baffle.The stress on the baffle during the shaking process and the change of the force on the whole liquid tank are analyzed.The results show that the installation of baffle will reduce the impact force on the tank wall,but the baffle will also be subjected to the impact load,which varies with the height. |
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