Observation on sloshing flow and hydrodynamic pressures on cylindrical liquefied natural gas tank with swash bulkhead

Abstract

In this study, a series of sloshing model tests were conducted for type-C tanks, particularly to observe the effects of the inner bulkhead and rings. In regular pitch motion, the internal flow by swash bulkhead and rings located inside the tank was observed. The frequency range near the resonance frequency was checked at filling heights of 70%, and sloshing-induced impact pressures were investigated. Through this study, the global flows inside the tank and local flows during impact occurrence at the hemispherical end of the tank were systematically observed, and the impact pressure pattern for each frequency ratio was compared. Due to the swash bulkhead located in the center of the tank, the flow does not move at once and the velocity of the flow is reduced by the inner rings. The flows passing through the swash bulkhead proceed with a time difference, overlapping with the first wave, generating various types of sloshing impact. The results of computational fluid dynamics calculation and the experiment were also compared for limited conditions.