Study of the ability of multiphase continuum models to predict core-annulus flow†
Study of the ability of multiphase continuum models to predict core-annulus flow†
复制标题
DOI：
10.1002/aic.11276
复制
发表时间：
2007-10
期刊：
影响因子：
3.7
通讯作者：
S. Benyahia;M. Syamlal;T. O'Brien
中科院分区：
文献类型：
--
作者：
S. Benyahia;M. Syamlal;T. O'Brien
我们使用完善的核心-环空流态作为数值基准来评估气固连续体模型和边界条件对形式和参数建模的敏感性。通过使用瞬态、一维、与网格无关的数值解，我们避免了使用推测闭合项，并表明颗粒流动力学理论 (KTGF) 足以模拟核心-环空状态。由于高固体浓度区域的波动运动，该状态出现在时间平均溶液中。这些波动对重力加速度 (g) 和颗粒能量耗散项最敏感。波动频率为α。波动的影响如此显着，以至于降低恢复系数（KTGF 参数）实际上会增加平均颗粒温度。固体动量和颗粒能量方程的壁边界条件决定了核心-环空流动状态。它们必须在壁上引起粒状能量的净耗散才能预测该状态。 © 2007 美国化学工程师学会 AIChE J，2007
We use the well established core-annulus flow regime as a numerical benchmark to evaluate the sensitivity of gas–solids continuum models and boundary conditions to model formalisms and parameters. By using transient, 1D, grid-independent numerical solutions, we avoid the use of speculative closure terms and show that the kinetic theory of granular flow (KTGF) is sufficient to model core-annulus regime. That regime arises in the time-average solution as a consequence of the fluctuating motion of regions with high solids concentration. These fluctuations are most sensitive to the gravitational acceleration (g) and granular energy dissipation terms. The fluctuation frequency is α . The effect of fluctuations is so dominant that decreasing the restitution coefficient (KTGF parameter) actually increases the average granular temperature. The wall boundary conditions for solids momentum and granular energy equations dictate the core-annulus flow regime. They must cause a net dissipation of granular energy at the wall for predicting that regime. © 2007 American Institute of Chemical Engineers AIChE J, 2007