摘要
This paper presents the study of the dynamic characteristics of confined mixed pebble beds with different friction under different vibration conditions using the discrete element method.Theλsegre-gation index is used to quantify the degree of particle mixing or segregation.The percolation,convection and diffusion mechanisms are responsible for the segregation patterns of the mixed pebble.The results show the degree of segregation can be suppressed by decreasing the vibration acceleration or free space height below a threshold.Further simulation reveals the threshold of vibration acceleration or free space height both are related to the bed height increment which determines the strength of the percolation mechanism.In addition,the strength of percolation and convection becomes weaker by decreasing the friction of particles and walls,which makes the pebbled bed remains in a mixed state under vibration.These findings are significant to clarify the main factors behind the three segregation mechanisms and hence provide solutions to retaining the mixed state of the Li2TiO3&Be12Ti mixed pebble bed.
基金
the financial support of the National MCF Energy R&D Program(No.2019YFE03130001)
the Comprehensive Research Facility for Fusion Technology(CRAFT)Program of China(Contract No.2018-000052-73-01-001228)
the National Natural Science Foundation of China(No.12105315&12205330)
the Science Foundation of ASIPP(No.DSJ-2021-05).
