Hydrodynamics of fluidization using kinetic theory: an emerging paradigm 2002 Flour-Daniel lecture
Hydrodynamics of fluidization using kinetic theory: an emerging paradigm 2002 Flour-Daniel lecture
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DOI：
10.1016/j.powtec.2004.09.025
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发表时间：
2004-11-11
影响因子：
5.2
通讯作者：
Singh, RK
中科院分区：
文献类型：
--
作者：
Gidaspow, D;Jung, JW;Singh, RK
用颗粒流动力学理论对流态化的文献进行了评述。关于颗粒的固体压力与颗粒温度和固体体积分数的状态方程，类似于气体的范德瓦尔斯方程，已被实验证明是相当正确的。实验还表明，由动力学理论得到的颗粒粘度表达式与用经典方法测得的值相同。我们使用基于动力学理论的粒子图像速度（PIV）计证明了流化过程中存在两种湍流：1。单个粒子的随机振荡，由经典颗粒温度和2测量。由粒子簇运动引起的湍流，用平均粒子法向雷诺应力来测量。这两种湍流产生了两种混合，在粒子水平上的混合和在团簇或气泡水平上的混合。为了计算颗粒温度，必须将其编程到计算流体力学（CFD）代码中。代码本身计算雷诺应力，类似于通过直接数值计算计算单相湍流。世界上几个研究小组的CFD模拟表明，多相流模型正确地预测了流化床的瞬态和时间平均行为：气泡、团簇和流态。过去十年的两个挑战问题表明，水动力模型在发表之前至少可以定性地预测径向和轴向剖面。(C) 2004 Elsevier B.V.版权所有
A critical review of the literature on fluidization using the kinetic theory of granular flow is presented. An equation of state for the particles relating solids pressure to the granular temperature and the solids volume fraction, similar to the van der Waals equation for gases, has been verified experimentally to be reasonably correct. Experiments have also shown that the particulate viscosity expression obtained from the kinetic theory gives the same values as that measured by classical methods.We demonstrated using a kinetic theory based particle image velocity (PIV) meter that there are two kinds of turbulence in fluidization:1. random oscillations of individual particles, measured by the classical granular temperature and2. turbulence caused by the motion of clusters of particles, measured by the average particle normal Reynolds stress.These two kinds of turbulence give rise to two kinds of mixing, mixing on the level of a particle and mixing on the level of cluster or bubble. To compute the granular temperature, it must be programmed into the computational fluid dynamics (CFD) codes. The code itself computes the Reynolds stresses, similar to the calculation of single-phase turbulence by direct numerical computation.CFD simulations by several groups throughout the world have shown that the multiphase flow models correctly predict transient and time-averaged behavior of fluidized beds: bubbles, clusters and flow regimes. Two challenge problems in the last decade show the capability of the hydrodynamic models to predict, at least qualitatively, radial and axial profiles before their publication. (C) 2004 Elsevier B.V. All rights reserved.