Simplified two-fluid model coupled with EMMS drag for simulating gas-solid flow

doi:10.11949/j.issn.0438-1157.20180065

Abstract

Abstract:

A simplified two-fluid model (STFM) combined with energy-minimization multi-scale (EMMS) drag was proposed for accurate and fast simulation of gas-solid flows. In this new approach, solid phase pressure was calculated by an empirical correlation without considering solid phase viscosity and interphase momentum transfer was calculated from EMMS drag model by taking into account of coupled effects of meso-scale structures. A lab-scale bubbling fluidized bed was successfully simulated in 3D by this approach. STFM coupled with EMMS drag had comparable simulation results to FTFM coupled with EMMS drag, and both agreed well with experimental data. Compared to FTFM, STFM doubled simulation speed and thus significantly reduced computational cost. The gas-solid simulation suggests that drag model has a primarily dominant effect, followed by solid phase stress. The model of STFM combined with EMMS drag has large potentials in rapid simulation of commercial gas-solid reactors.

Key words: EMMS drag, two-fluid model, fluidization, multiphase flow, computational fluid dynamics

摘要：

提出了一种耦合EMMS曳力的简化双流体模型，该模型忽略固相黏度，用简单的经验关联式来计算固相压力，并且耦合考虑了介尺度结构的EMMS曳力模型来计算气固相间作用力。采用简化双流体模型成功模拟一个三维实验室尺度鼓泡流化床，数值模拟结果与完整双流体模型以及实验测量结果进行了比较，结果表明耦合EMMS曳力的简化双流体模型模拟结果与完整双流体模型耦合EMMS曳力的模拟结果基本相当，并且都与实验结果吻合良好，然而简化双流体模型的计算速度是完整双流体模型的两倍以上。这表明曳力模型在气固模拟中起着主导作用，而固相应力的作用是其次的，耦合EMMS曳力的简化双流体模型在实现工业规模气固反应器快速模拟中具有巨大潜力。

关键词: EMMS曳力, 双流体模型, 流态化, 多相流, 计算流体力学

CLC Number:

TQ021.1

QIU Xiaoping, WANG Limin, YANG Ning. Simplified two-fluid model coupled with EMMS drag for simulating gas-solid flow[J]. CIESC Journal, 2018, 69(5): 1867-1872.

邱小平, 王利民, 杨宁. 耦合EMMS曳力与简化双流体模型的气固流动模拟[J]. 化工学报, 2018, 69(5): 1867-1872.

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