重力条件对稠密气固两相流动特性影响的数值模拟

基于稠密气体分子运动论和颗粒动力学,考虑颗粒与颗粒之间离散介质特性,应用稠密气固两相流动的欧拉-欧拉双流体数学模型,采用大涡模拟求解气相湍流流动,数值模拟航天环境中部分重力条件和地面重力条件下气-固反应器内稠密气固两相流体的流动行为,得到了颗粒浓度、气相和颗粒相速度以及源于颗粒间碰撞而产生小尺度颗粒脉动强度的详细分布.计算结果表明：重力条件是影响稠密颗粒流体动力特性的重要因素,重力降低有利于在系统中产生非均匀结构和增强小尺度颗粒脉动强度.

NUMERICAL SIMULATION OF DENSE GAS-SOLID TWO-PHASE FLOW CHARACTERS AFFECTED BY GRAVITY CONDITIONS

An Euler-Euler two fluid model was applied to study the dense gas-solid two-phase flow behaviors with the aerospace and ground gravity conditions in gas-fluidized reactor Discrete medium characters of particles were considered on the basis of the kinetic theory of dense gases and the kinetic theory of granular in this model. Turbulence flow of gas phase was modeled by the large eddy simulation. Detailed results on particles concentration and velocity, gas velocity and small-scale particles fluctuation intensity originated from the particle-particle collision were numerically simulated, The calculate results showed gravity conditions took greatly effects on the dense particles-fluid dynamic characters, the decrease of gravity was in favor of generating the heterogeneous structure and enhancing the small-scale particles fluctuation intensity.