流固耦合传热作用下两颗粒拖曳-接触-翻滚运动研究  

Investigation of drafting-kissing-tumbling movement of two particles with conjugate heat transfer

作　　者：张销杰 赵千千 黄荣宗 ZHANG Xiaojie;ZHAO Qianqian;HUANG Rongzong(School of Energy Science and Engineering,Central South University,Changsha 410083,China)

机构地区：[1]中南大学能源科学与工程学院,长沙410083

出　　处：《物理学报》2025年第4期191-199,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:52376086,52006244)资助的课题.

摘　　要：颗粒-流体界面处的耦合传热以及颗粒间的碰撞在颗粒沉降过程中起着至关重要的作用.本文基于热颗粒流体积格子Boltzmann方法对流固耦合传热作用下封闭通道中两颗粒沉降过程拖曳-接触-翻滚运动开展了数值模拟研究,探究了颗粒与流体比热容比R_(cv)、Grashof数G_(r)、颗粒初始温度对拖曳-接触-翻滚运动的影响.结果表明,随着比热容比R_(cv)的增加,两冷颗粒沉降过程拖曳-接触-翻滚运动的拖曳时长和翻滚时长均减小,而接触时长则相应增加.随着Grashof数G_(r)的增加,两冷颗粒沉降过程拖曳-接触-翻滚运动的拖曳时长显著减小,但接触时长和翻滚时长则近似保持不变.两冷颗粒沉降过程拖曳-接触-翻滚运动发生的时刻最早,一冷一热颗粒次之,两热颗粒最晚;颗粒初始温度低于流体温度对拖曳-接触-翻滚运动的促进作用主要体现在拖曳阶段和接触阶段,颗粒初始温度对翻滚时长则近似无影响.The conjugate heat transfer at the particle-fluid interface and the collision between particles play a crucial role in the sedimentation process of particles.In this work,the recent volumetric lattice Boltzmann method for thermal particulate flows with conjugate heat transfer is adopted to investigate the drafting-kissing-tumbling movement in the sedimentation process of two particles in a closed channel.This volumetric lattice Boltzmann method is based on double distribution functions,with the density distribution function used for the velocity field and the internal energy distribution function used for the temperature field.It is a single-domain approach,and the nonslip velocity condition within the solid domain can be strictly ensured.The difference in thermophysical properties between the solid and fluid can be correctly handled,and the conjugate heat transfer condition can be automatically achieved without any additional treatments.Based on this particle-resolved simulation,the influences of the solid-to-fluid specific heat ratio,the Grashof number,and the particle’s initial temperature on the drafting-kissing-tumbling movement are discussed in detail.It is found that the fluid cooled by the particle and thus subjected to the downward buoyancy force can promote particle sedimentation.As the specific heat ratio increases,the particle’s temperature rises relatively slowly.In the sedimentation of two cold particles,the drafting duration and tumbling duration of the drafting-kissing-tumbling movement decrease when the heat capacity ratio increases.In contrast,the kissing duration increases as the heat capacity ratio increases.When the Grashof number increases,the heat transfer between the particle and fluid is enhanced,and the drafting duration significantly decreases while the kissing duration and tumbling duration remain almost unchanged in the sedimentation of two cold particles.The particle’s initial temperature greatly affects the occurrence moment of the drafting-kissing-tumbling movement.To be spec

关 键 词：颗粒沉降 耦合传热 拖曳-接触-翻滚 

分 类 号：O353.4[理学—流体力学] TK124[理学—力学]