Abstract:

A secondorder moment model of particles in dense gassolid flow is proposed based on the kinetic theory of granular flow.The solid phase constitutive model is closed with the approximated thirdorder moment enclosure equation of particle velocity from the elementary transport theory.The boundary conditions of particles are proposed in considering the energy transfer and dissipations by collisions between the wall and particles.Flow behavior of particles is numerically simulated in a bubble fluidized bed, which indicates the distinct anisotropy behavior of the turbulent particles.Simulated particle velocities are in agreement with the measurements by Muller et al(2008) and Yuu et al(2001).Predicted secondorder moment of velocity has the same trend as that of measurements.The calculated Reynolds stresses per unit bulk density agree with the measured data by Muller et al(2008) and with the fluctuating velocity of particles measured by Yuu et al(2001).

Key words:

二阶矩, 各向异性颗粒动理学, 鼓泡床, 数值模拟

摘要： 采用颗粒动理学方法，考虑颗粒速度脉动各向异性，建立颗粒相二阶矩模型。应用初等输运理论，对三阶关联项进行模化和封闭。考虑颗粒与壁面之间的能量传递和交换，建立颗粒相边界条件模型。数值模拟鼓泡流化床内气固两相流动特性，模拟结果表明鼓泡流化床内颗粒相湍流脉动具有明显的各向异性。预测颗粒速度与Muller等和Yuu等实测结果相吻合。预测颗粒脉动速度二阶矩与Muller等实验结果变化趋势相同。统计得到的固相雷诺应力型二阶矩与Muller等实测颗粒脉动速度二阶矩和Yuu等实测颗粒脉动速度相吻合。

关键词:

二阶矩, 各向异性颗粒动理学, 鼓泡床, 数值模拟