Research On The Movement Characteristics Of A Single Particle In A Rotating Flow Field

With the continuous development of the theory and technology of solid-liquid two-phase flow,the phenomenon of particle movement in rotational flow field has widely existed in fields such as chemical industry,petroleum,mining and hydrate solid-state fluidized mining.So,it is necessary to further understand the motion characteristics of particles in rotational flow field.Most studies at home and abroad mainly focus on the macroscopic motion of particle swarm in rotational flow field,and there was fewly study about the quantification motility characteristics of particle swarm and the single particle motion characteristics in rotational flow field.Therefore,it is very importment to study the motion characteristics of single particle in rotational flow field.In this paper,according to the research idea of the single particle motion in rotational flow field.The following research work has been carried out on the motion characteristics of single particle in rotational flow field by used the particle motion experiment device and the EDEM-FLUENT coupled numerical simulation method.(1)The research status of particle motion characteristics in rotational flow field and the solid-liquid two-phase flow is understand by the paper at home and abroad.(2)The particle motion experiment device in rotational flow field has been designed and manufactured.Analyses are performen to the motion of particle in rotational flow field,and the whole motion process of the single particle is divide into two stages of development and stability.(3)In this paper,a series of experiments has been performed by using the experiment device.The single particle movement state discriminant formula and the single particle motion trajectory equation were obtained.The influences of flow fields,the rotational speed of the flow field and the particle diameter on the motion characteristics of the single particle motion are studied.The results show that rotational speed of the flow field with the increase,the variation range of the particle velocity and acceleration gradually increases.And the peak value and the amplitude of the centrifugal force of the single particle is also gradually increases,the change tendency of the particle subjected to the drag force in the stable phase is obviously different.With the increase of particle diameter,the variation range of particle velocity and acceleration gradually decreases,and remains stable during the stabilization phase,while the peak value of centrifugal force of the single particle is firstly decreases and then increases gradually.When the particle diameter is small,the value of the drag force is a small range of fluctuations in the stable phase.Relative to the small particle diameter,the drag force is very stable in the stable phase.(4)Finally,based on the experiments of particle motion,a comparison of between simulation results and experimental data in literature is carried out to valid the proposed EDEM-FLUENT model.In this work the model has been used to simulate and analyze the collision characteristics,force analysis and energy less a single particle in rotational flow field.The results show that as the particle density increases,the number of collisions between the particle and the wall surface decreases.Then,when the particle density is 2230 kg/m3,the number of collisions between the particle and the wall surface reache a minimum value.As the density increases,the number of collision gradually increases.When the particle density is greater than 2550 tg/m3,the number of collisions decreases again.When the viscosity of the liquid gradually increases,the number of collisions between the particle and the wall also increases,and the rotation of the particle in rotational flow field is mainly affect by the wall.Collisions between the particle and the wall will lose a lot of energy,but the fluid and wall will continue to provide energy for the upward movement of the particle.