高浓度颗粒气固两相流动的二阶矩模型的数值模拟

采用动理学方法,用各向异性的M axwell颗粒速度分布函数,建立颗粒相Boltzm ann方程,分别取零次矩、一次矩和二次矩得到颗粒相连续方程、动量方程和二阶矩方程.模拟计算得到上升管内颗粒流场分布和脉动速度分布,与实验结果比较表明:各向异性颗粒动理学能够反映颗粒流动特性,从而能够更全面地认识高颗粒浓度气固两相流动过程.

Second order moments model and numerical simulation of dense gas-solid two-phase flow

Kinetic theory of granular flow that was wide used in theoretical studies of gas-solid two-phase flow is based on non-uniform dense gases molecular dynamics.The conservation equations of solid phase were derived from the assumption of isotropic Maxwell velocity distribution simulating particle flow to molecular motion.However,particle velocity distribution is anisotropic due to energy dissipation by particle collisions.Based on kinetic theory of molecular dynamics,Boltzmann equation of velocity fluctuation of particles was established under the assumption of anisotropic Maxwell velocity distribution.The mass,momentum and energy equations were obtained by taken from first and second orders moments.Particle flow behavior and fluctuating velocity distribution of particles were simulated,and compared with experiments.Simulations indicated that the anisotropic kinetic theory of granular flow fully expressed flow behavior of particles,and processes of dense gas-solid flow.