Numerical Study On Dynamic Behavior Of Liquid Bridge Between Particles Based On CFD-DEM-IB

The cargo slip caused by liquefaction of nickel,iron ore and other solid bulk cargo may lead the ship to suddenly lose stability and capsize,which has become a major accident hidden danger in maritime safe transportation.The liquefaction of solid bulk cargo is closely related to the internal moisture migration,and the water mainly exists in the form of liquid bridge.The dynamic evolution of liquid bridge will inevitably affect the process of water migration.Although the current research methods can explore the influence of liquefied cargo on ship stability,it is difficult to simulate the evolution of liquid bridge.In this paper,the dynamic behavior of the intergranular liquid bridge was investigated from a mesoscopic point of view by means of self-programming.Firstly,the solution of "liquid bridge-air" was realized based on the N-S equation,the equation of volume of liquid and continuum surface force model,and the discrete element method was used to solve the particle.Referring to VOF method,the volume fraction of particles is used to express particles in fluid domain.The fluid-solid interaction was solved by the immersed boundary method.The "particle liquid bridge air" three-phase coupling numerical model considering capillary effect was built.Thus,a three-phase coupling numerical model of "particle-liquid bridge-air" considering capillary action was established,and a set of numerical algorithm of solid-liquid-gas threephase flow coupling was developed based on Fortran.The accuracy of the coupling model and algorithm was verified by the experimental results.Based on the numerical model,the stability of the liquid bridge between the plates and between two spherical particles of equal diameter was studied,and the influence of different parameters on static liquid bridge force was explored.The dynamic tensile fracture behavior of the liquid bridge between spherical particles is analyzed,and the influencing factors of critical fracture distance were obtained,and the variation trend of dynamic hydraulic bridge force was monitored.Finally,the adhesion behavior of the liquid bridge to the particles under different degree of wettability was investigated.The solid-liquid-gas three-phase coupling numerical method considering capillary action established in this paper can be further extended as a numerical tool for analyzing the liquefaction mechanism and prediction of solid bulk,which provides an effective numerical basis and reference for the future research on liquefaction mechanism and ensures the safety of maritime transport.