Numerical study on pressure variation of marine liquefied natural gas (LNG) fuel tanks under sinusoidal sloshing excitation

Abstract

In this paper, a numerical model considering phase change and external heat leakage is established to study the pressure variation and temperature distribution of marine Liquefied Natural Gas (LNG) fuel tanks under sinusoidal sloshing excitation. The Volume of Fluid (VOF) method, coupled with the mesh motion treatment, is adopted to predict the movement of the vapor-liquid interface. The sinusoidal sloshing excitation is realized by a User-Defined Function (UDF). The feasibility of the numerical model is verified by comparisons with related fluid sloshing experiments. The thermal physical process in the LNG fuel tank under sloshing conditions and the static condition are compared, and the effects of sloshing amplitude and frequency on the pressure and temperature distribution of the tank are also studied. The results show that when the external sloshing excitation frequency is close to the first natural frequency of the LNG fuel tank, the tank pressure will drop rapidly in a short time, resulting in the shutdown of Natural Gas (NG) engine. Meanwhile, the influence of the sloshing excitation on the mass transfer is theoretically analyzed by the definition of the sloshing Nusselt number.