Fluid sloshing hydrodynamics in a cryogenic fuel storage tank under different order natural frequencies

Liquid hydrogen is a promising energy carrier due to its excellent performance. However, liquid hydrogen sloshing usually causes serious issues on its safety production, storage, transportation, application and management. To study fluid sloshing in cryogenic storage tanks, a numerical calculation model is developed with considerations of the environmental heat leakage and phase change occurring at the free interface. The VOF model, coupled with the mesh motion treatment, is adopted to predict fluid sloshing under the first three order natural frequencies. Validated against to the experimental data, the calculation uncertainty is limited within 5.0%. The sloshing force and moment, the phase distribution and the interface shape, the dynamic fluctuation of the liquid-vapor interface and the fluid pressure variations are numerically investigated. The results show that the natural frequency has caused obvious effects on fluid sloshing hydrodynamics. Generally, the sloshing force and moment increase with the natural frequency, and the sloshing force of the first order natural frequency has obvious reductions. Meanwhile, obvious interface fluctuations and large elevation motions take shape in the first order natural frequency case. As the interface variation promotes the heat transfer from the vapor to the liquid, the largest fluid pressure drop also forms and occurs in the first order natural frequency condition. In brief, the first order natural frequency results in serious fluid sloshing and large amplitude interface fluctuation, and should be given enough considerations. The present study is significant to depth understanding on fluid sloshing performance during fuel transportation and may supply some technique supports for the design on cryogenic fuel storage tanks