Rushton涡轮搅拌槽内流场特性及颗粒运动行为数值模拟

doi:10.16085/j.issn.1000-6613.2021-1369

摘要/Abstract

摘要：

基于计算流体动力学（CFD）方法，采用大涡模拟（LES）和拉格朗日颗粒追踪技术计算了Rushton涡轮搅拌槽内流场特性及三种St颗粒的运动行为。平均流场（切向速度、轴向速度和径向速度）、颗粒速度及浓度分布方面与实验值的吻合度较好，验证了数值模拟的可靠性。结果表明，搅拌流场及颗粒运动均呈现循环流特性，当转速N=313r/min不变时，St=0.24的小颗粒几乎实现了均匀分布；而St=37.3的大颗粒与流体的跟随性较差，底部沉积率较高，容器顶部会出现一定的颗粒空白区。叶轮附近产生一系列的湍流涡结构，并且由于剧烈的颗粒-壁面碰撞，该位置颗粒拟温度最高；小颗粒（St=0.24）的运移主要受叶片后方尾涡的控制，均匀分布在低涡量区；而大颗粒（St=37.3）由于具有较大的惯性，运动不再由涡主导，很快被叶轮甩向边壁，穿过了尾涡所形成的高涡量区，故而叶轮对附近大颗粒的搅拌效果较差。

关键词: 搅拌容器, 计算流体力学, 液固两相流, 涡旋结构, 数值模拟

Abstract:

By applying computational fluid dynamics (CFD) method, the large eddy simulation (LES) and Lagrangian particle tracking technology were used to calculate the flow field characteristics in the Rushton turbine stirred tank and the movement behavior of three kinds of St particles. The mean flow field (tangential velocity, axial velocity and radial velocity), particle velocity and concentration distribution were in good agreement with the experiment, which verified the reliability of the numerical simulation. The results showed that the stirred flow field and particle movement presented the characteristics of circulating flow. When the rotation speed N was constant at 313r/min, the small particles of St=0.24 were almost evenly distributed. However, the followability of large particles of St=37.3 with the fluid was poor, the bottom deposition rate was high, and a certain particle blank zone appeared on the top of the vessel. A series of turbulent vortex structures were generated near the impeller, and due to the violent particle-wall collision, the granular temperature at this location was the highest. The migration of small particles (St=0.24) was mainly controlled by the trailing vortices behind the blades, and they were evenly distributed in the low vorticity zone. Due to the large inertia of large particles (St=37.3), their motion was no longer dominated by the vortex, and was quickly thrown to the side wall by the impeller. They passed through the high vortex zone formed by the trailing vortices, so the impeller had a poor agitating effect on nearby large particles.

Key words: stirred vessel, computational fluid dynamics, liquid-solid two-phase flow, vortex structure, numerical simulation

中图分类号:

TQ051.7

王志杰, 赵彦琳, 姚军. Rushton涡轮搅拌槽内流场特性及颗粒运动行为数值模拟[J]. 化工进展, 2021, 40(12): 6479-6489.

WANG Zhijie, ZHAO Yanlin, YAO Jun. Numerical simulation of flow field characteristics and particle motion behavior in Rushton turbine stirred tank[J]. Chemical Industry and Engineering Progress, 2021, 40(12): 6479-6489.

图/表 13

图1 搅拌槽几何模型与坐标系

表1 3种粒径颗粒的计算参数

案

例

颗粒直径d_p

/mm

颗粒密度ρ_s

/kg·m^-3

颗粒体积分数V_s/%

斯托克斯数St

颗粒包

数量/个

1×10⁶

1×10⁶

1×10⁶

图2 LES的网格划分

图3 平均速度场

图4 流体平均速度与Nouri等[13]实验结果的对比

图5 St=2.6颗粒平均速度与Nouri等[13]实验结果的对比

图6 St=2.6颗粒在2r/T=0.136剖面浓度分布

图7 叶轮角度β=0时St=2.6颗粒的瞬态分布及速度矢量图

图8 St=0.24、2.6和37.3颗粒的轴向浓度分布

图9 St=2.6时y=0截面颗粒拟温度θ分布云图

图10 y=0剖面上不同St颗粒的拟温度与体积分数Vs的关系

图11 Q准则的涡旋结构（Q/N2=1043）

图12 叶轮角度β=20°的瞬态涡量ω及3种St颗粒分布

参考文献 31

1	黎义斌, 梁开一, 歹晓晖, 等. 搅拌反应器气液两相流混合过程的涡旋效应数值模拟[J]. 化工进展, 2021, 40(1): 99-110.
	LI Yibin, LIANG Kaiyi, DAI Xiaohui, et al. Numerical simulation of eddy effect in the mixing process of gas-liquid two-phase flow in stirred reactor[J]. Chemical Industry and Engineering Progress, 2021, 40(1): 99-110.
2	李文金, 周勇军, 袁名岳, 等. 几种框式桨搅拌槽内流动特性的比较研究[J]. 化工学报, 2021, 72(4): 1998-2005.
	LI Wenjin, ZHOU Yongjun, YUAN Mingyue, et al. Comparative study of flow characteristics in a stirred tank with different types of frame impellers[J]. CIESC Journal, 2021, 72(4): 1998-2005.
3	WANG S Y, JIANG X X, WANG R C, et al. Numerical simulation of flow behavior of particles in a liquid-solid stirred vessel with baffles[J]. Advanced Powder Technology, 2017, 28: 1611-1624.
4	张桂夫, 王鲁海, 朱雨建, 等. 基于PIV测量的涡轮流量计响应分析[J]. 仪器仪表学报, 2013, 34(10): 2381-2387.
	ZHANG Guifu, WANG Luhai, ZHU Yujian, et al. Turbine flowmeter response analysis based on PIV measurement[J]. Chinese Journal of Scientific Instrument, 2013, 34(10): 2381-2387.
5	周勇军, 袁名岳, 孙存旭. 改进型框式组合桨搅拌釜内流场特性[J]. 化工进展, 2019, 38(12): 5306-5313.
	ZHOU Yongjun, YUAN Mingyue, SUN Cunxu. Investigating on flow field in stirred tank equipped with improved frame type combined impellers[J]. Chemical Industry and Engineering Progress, 2019, 38(12): 5306-5313.
6	ZHAO Y L, TANG C Y, YAO J, et al. Investigation of erosion behavior of 304 stainless steel under solid-iquid jet flow impinging at 30°[J]. Petroleum Science, 2020, 17(4): 1135-1150.
7	HOSEINI S S, NAJAFI G, GHOBADIAN B, et al. Impeller shape-optimization of stirred-tank reactor: CFD and fluid structure interaction analyses[J]. Chemical Engineering Journal, 2021, 413: 127497.
8	DERKSEN J J. Numerical simulation of solids suspension in a stirred tank[J]. AIChE Journal, 2003, 49(11): 2700-2714.
9	MALIK S, LÉVÊQUE E, BOUAIFI M, et al. Shear improved Smagorinsky model for large eddy simulation of flow in a stirred tank with a Rushton disk turbine[J]. Chemical Engineering Research and Design, 2016, 108: 69-80.
10	HARTMANN H, DERKSEN J J, MONTAVON C, et al. Assessment of large eddy and RANS stirred tank simulations by means of LDA[J]. Chemical Engineering Science, 2004, 59(12): 2419-2432.
11	RAMÍREZ-CRUZ J, SALINAS-VÁZQUEZ M, ASCANIO G, et al. Mixing dynamics in an uncovered unbaffled stirred tank using large-Eddy simulations and a passive scalar transport equation[J]. Chemical Engineering Science, 2020, 222: 115658.
12	TAMBURINI A, CIPOLLINA A, MICALE G, et al. CFD simulations of dense solid-liquid suspensions in baffled stirred tanks: prediction of solid particle distribution[J]. Chemical Engineering Journal, 2013, 223: 875-890.
13	NOURI J M, WHITELAW J H. Particle velocity characteristics of dilute to moderately dense suspension flows in stirred reactors[J]. International Journal of Multiphase Flow, 1992, 18(1): 21-33.
14	LI G H, GAO Z M, LI Z P, et al. Particle‐resolved PIV experiments of solid‐liquid mixing in a turbulent stirred tank[J]. AIChE Journal, 2018, 64(1): 389-402.
15	GIMBUN J, RIELLY C D, NAGY Z K, et al. Detached eddy simulation on the turbulent flow in a stirred tank[J]. AIChE Journal, 2012, 58(10): 3224-3241.
16	SHI Pengyu, RZEHAK R. Solid-liquid flow in stirred tanks: Euler-Euler/RANS modeling[J]. Chemical Engineering Science, 2020, 227: 115875.
17	GONG H, HUANG F L, LI Z P, et al. Mechanisms for drawdown of floating particles in a laminar stirred tank flow[J]. Chemical Engineering Journal, 2018, 346: 340-350.
18	ZHAO Y L, WANG Y Z, YAO J, et al. Reynolds number dependence of particle resuspension in turbulent duct flows[J]. Chemical Engineering Science, 2018, 187: 33-51.
19	LI G H, LI Z P, GAO Z M, et al. Particle image velocimetry experiments and direct numerical simulations of solids suspension in transitional stirred tank flow[J]. Chemical Engineering Science, 2018, 191: 288-299.
20	SHI Pengyu, RZEHAK R. Bubbly flow in stirred tanks: Euler-Euler/RANS modeling[J]. Chemical Engineering Science, 2018, 190: 419-435.
21	CORONEO M, MONTANTE G, PAGLIANTI A, et al. CFD prediction of fluid flow and mixing in stirred tanks: numerical issues about the RANS simulations[J]. Computers & Chemical Engineering, 2011, 35(10): 1959-1968.
22	LU Z Y, LIAO Y, QIAN D Y, et al. Large eddy simulations of a stirred tank using the lattice Boltzmann method on a nonuniform grid[J]. Journal of Computational Physics, 2002, 181(2): 675-704.
23	ZHANG Y H, YANG C, MAO Z S. Large eddy simulation of the gas-liquid flow in a stirred tank[J]. AIChE Journal, 2008, 54(8): 1963-1974.
24	MONTANTE G, BRUCATO A, LEE K C, et al. An experimental study of double-to-single-loop transition in stirred vessels[J]. The Canadian Journal of Chemical Engineering, 1999, 77(4): 649-659.
25	YIANNESKIS M, POPIOLEK Z, WHITELAW J H. An experimental study of the steady and unsteady flow characteristics of stirred reactors[J]. Journal of Fluid Mechanics, 1987, 175: 537-555.
26	胡陈枢. 流化床内流动、混合与反应的多尺度模拟研究[D]. 杭州: 浙江大学, 2019.
	HU Chenshu. Multi-scale modeling of hydrodynamics, mixing and reactions in fluidized beds[D]. Hangzhou: Zhejiang University, 2019.
27	SUN L Y, XU W G, LU H L, et al. Simulated configurational temperature of particles and a model of constitutive relations of rapid-intermediate-dense granular flow based on generalized granular temperature[J]. International Journal of Multiphase Flow, 2015, 77: 1-18.
28	EATON J K, FESSLER J R. Preferential concentration of particles by turbulence[J]. International Journal of Multiphase Flow, 1994, 20: 169-209.
29	YAO J, ZHAO Y L, HU G L, et al. Numerical simulation of particle dispersion in the wake of a circular cylinder[J]. Aerosol Science and Technology, 2009, 43(2): 174-187.
30	YAO J, ZHAO Y L, LI N, et al. Mechanism of particle transport in a fully developed wake flow[J]. Industrial & Engineering Chemistry Research, 2012, 51(33): 10936-10948.
31	LI D, FAN J R, LUO K, et al. Direct numerical simulation of a particle-laden low Reynolds number turbulent round jet[J]. International Journal of Multiphase Flow, 2011, 37(6): 539-554.

[1]	郭强, 赵文凯, 肖永厚. 增强流体扰动强化变压吸附甲硫醚/氮气分离的数值模拟[J]. 化工进展, 2023, 42(S1): 64-72.
[2]	邵博识, 谭宏博. 锯齿波纹板对挥发性有机物低温脱除过程强化模拟分析[J]. 化工进展, 2023, 42(S1): 84-93.
[3]	王云飞, 秦蕊, 郑利军, 李焱, 李清平. 旋转填充床CFD模拟研究进展[J]. 化工进展, 2023, 42(S1): 1-9.
[4]	王太, 苏硕, 李晟瑞, 马小龙, 刘春涛. 交流电场中贴壁气泡的动力学行为[J]. 化工进展, 2023, 42(S1): 133-141.
[5]	孙继鹏, 韩靖, 唐杨超, 闫汉博, 张杰瑶, 肖苹, 吴峰. 硫黄湿法成型过程数值模拟与操作参数优化[J]. 化工进展, 2023, 42(S1): 189-196.
[6]	陈匡胤, 李蕊兰, 童杨, 沈建华. 质子交换膜燃料电池气体扩散层结构与设计研究进展[J]. 化工进展, 2023, 42(S1): 246-259.
[7]	刘炫麟, 王驿凯, 戴苏洲, 殷勇高. 热泵中氨基甲酸铵分解反应特性及反应器结构优化[J]. 化工进展, 2023, 42(9): 4522-4530.
[8]	罗成, 范晓勇, 朱永红, 田丰, 崔楼伟, 杜崇鹏, 王飞利, 李冬, 郑化安. 中低温煤焦油加氢反应器不同分配器中液体分布的CFD模拟[J]. 化工进展, 2023, 42(9): 4538-4549.
[9]	赵曦, 马浩然, 李平, 黄爱玲. 错位碰撞型微混合器混合性能的模拟分析与优化设计[J]. 化工进展, 2023, 42(9): 4559-4572.
[10]	卜治丞, 焦波, 林海花, 孙洪源. 脉动热管计算流体力学模型与研究进展[J]. 化工进展, 2023, 42(8): 4167-4181.
[11]	叶振东, 刘涵, 吕静, 张亚宁, 刘洪芝. 基于钙镁二元盐的热化学储能反应器的性能优化[J]. 化工进展, 2023, 42(8): 4307-4314.
[12]	俞俊楠, 俞建峰, 程洋, 齐一搏, 化春键, 蒋毅. 基于深度学习的变宽度浓度梯度芯片性能预测[J]. 化工进展, 2023, 42(7): 3383-3393.
[13]	单雪影, 张濛, 张家傅, 李玲玉, 宋艳, 李锦春. 阻燃型环氧树脂的燃烧数值模拟[J]. 化工进展, 2023, 42(7): 3413-3419.
[14]	王硕, 张亚新, 朱博韬. 基于灰色预测模型的水煤浆输送管道冲蚀磨损寿命预测[J]. 化工进展, 2023, 42(7): 3431-3442.
[15]	周龙大, 赵立新, 徐保蕊, 张爽, 刘琳. 电场-旋流耦合强化多相介质分离研究进展[J]. 化工进展, 2023, 42(7): 3443-3456.