Numerical Study Of The Effect Of Longitudinal Bulkhead On The Liquefiable Cargo Sloshing In Cargo Hold

The cargo which may liquefy is a class of bulk cargo containing fine particles and liquid water.When its water content exceeds a certain limit,the cargo may liquefy under the influence of external load such as vibration,collision and swing.This kind of cargo is called Group A Cargo in IMSBC Code.Compared with common cargo,easy-liquefication cargo is easier to liquefy and would cause severe loss of personnel and property when ships capsize happened.In order to explore the movement discipline of easy-liquefication cargo in the cargo hold,a series of work on sloshing of liquefied cargo in the cargo hold were carried out based on viscous fluid dynamics theory and CFD technology.The effect of liquefied cargo on ships movement can be described by solving the problem of forced motion sloshing in cargo hold.During the research,a typical compartment of a 57,000 DWT bulk carrier was selected as the subject of the study,and a cargo hold model with 1:66 scale ratio was built according to its actual geometry.As for the rheological behavior of liquefied cargo,the stress-strain relationship was described by the Herschel-Bulkley model and the Bingham plastic model of the non-Newtonian fluid.Based on the above numerical calculation model,the problem of sloshing motion was solved firstly by the second-developed FLUENT software for the forced motion cycle and amplitude sloshing conditions of different cargo holds.The time curve of the induced torque of the cargo tank on sloshing and the deformation of the free liquid surface was demonstrated,and the different sloshing situations of the liquid water and the fluid cargo were analyzed and compared.Then,the sloshing of fluidized cargo with different water content were examined in the cargo hold which added a complete partition longitudinal bulkhead in the middle,in order to analysis of the actual effect of this longitudinal bulkhead on cargo sloshing.Finally,three simpler longitudinal bulkhead layouts were simulated,and the results show the transportation safety could be greatly improved by setting the block in the surface layer of the fluidized cargo.