Analysis of dynamic characteristics of flow field in impinging stream reactor based on step jet

doi:10.11949/0438-1157.20211135

Abstract

Abstract:

The flow field characteristics of dynamic step impinging stream reactor were studied by experimental and numerical simulation methods, and the fluid flow law, turbulence characteristics and energy level under different inlet velocities were analyzed. The results show that under the condition of dynamic step inlet, the impact surface moved periodically between the two nozzles, and the flow parameters also changed periodically. The stagnation velocity was increased with the average inlet velocity. With the increase of the inlet velocity difference between the two nozzles, the moving speed of the impact surface was accelerated, and the fluid turbulence intensity in the impact zone was increased gradually. With the increase of the difference between the inlet average velocity and the inlet velocity, the average turbulent kinetic energy of XOZ plane in one cycle was gradually decreased. The flow field characteristics in dynamic impinging stream reactor and steady-state impinging stream reactor were compared to explore the influence of dynamic inlet conditions on the flow field characteristics of impinging stream reactor. The results show that the parameters of turbulent viscosity, turbulence intensity and turbulent kinetic energy of dynamic step impinging stream reactor were significantly higher than those of steady-state impinging stream reactor, and the gradient distribution of turbulent kinetic energy on the impact axis was greater than that of steady-state impinging stream reactor. Under the condition of dynamic inlet, the fluid turbulence in the impinging stream reactor was more intense and the energy level was higher, which was conducive to increasing the fluid disturbance and promoting mixing in the flow field.

Key words: impinging stream, dynamic control, numerical simulation, turbulent flow, experimental validation

摘要：

利用实验与数值模拟方法对动态阶跃型撞击流反应器流场特性进行研究，分析不同入口速度条件下流体流动规律、湍流特性以及能量水平。结果表明，动态阶跃型入口条件下，撞击面在两喷嘴之间周期性移动，流动参数也会发生周期性变化。随着入口平均速率的增大，驻点速度逐渐增大；随着两喷嘴入口速率差的增加，撞击面移动速度加快，撞击区流体湍流强度逐渐增加；随着入口平均速率与入口速率差的增大，XOZ平面在一个周期内的平均湍动能逐渐减小。对比动态撞击流反应器与稳态撞击流反应器内流场特性，探究动态入口条件对撞击流反应器流场特性的影响。结果表明，动态阶跃撞击流反应器湍流黏度、湍流强度和湍动能等参数均明显高于稳态撞击流反应器，撞击轴线上的湍动能梯度分布大于稳态撞击流反应器。动态入口条件下撞击流反应器流体湍动更剧烈，能量水平更高，有利于增加流场内流体扰动与促进混合。

关键词: 撞击流, 动态调节, 数值模拟, 湍流, 实验验证

CLC Number:

TQ 021.1

Jianwei ZHANG, Fengyuan AN, Xin DONG, Ying FENG. Analysis of dynamic characteristics of flow field in impinging stream reactor based on step jet[J]. CIESC Journal, 2022, 73(2): 622-633.

张建伟, 安丰元, 董鑫, 冯颖. 基于阶跃射流的撞击流反应器流场动态特性分析[J]. 化工学报, 2022, 73(2): 622-633.

Figures/Tables 22

Fig.1 Schematic diagram of the impinging stream mixer

Fig.2 The stagnation point speed under different number of grids

Fig.3 The distribution of velocity of impact axis under different grid numbers

Table 1 Inlet condition

速率差/(m/s)	平均速率/(m/s)
	1.5		1.75		2		2.25
	v_max/(m/s)	v_min/(m/s)	v_max/(m/s)	v_min/(m/s)	v_max/(m/s)	v_min/(m/s)	v_max/(m/s)	v_min/(m/s)
0.5	1.75	1.25	2	1.5	2.25	1.75	2.5	2
0.75	1.875	1.125	2.125	1.375	2.375	1.625	2.625	1.875
1	2	1	2.25	1.25	2.5	1.5	2.75	1.75

Fig.4 The absolute value of inlet velocity

Fig.5 The schematic diagram of experimental system

Fig.6 The movement of impact surface in flow field at different time

Fig.7 The PIV and CFD results in the component of absolute velocity in U direction of impact axis at ω = 0.4

Fig.8 The PIV and CFD results of vorticity absolute value on impact axis at ω = 0.4

Fig.9 The absolute velocity of impact axial under steady and dynamic conditions

Fig.10 The flow trajectory in reactor under steady and dynamic conditions

Fig.11 The distribution of helicity on impact axis under steady and dynamic conditions

Fig.12 The absolute value of average helicity of impact axis at different times under steady and dynamic conditions

Fig.13 The isogram of turbulent kinetic energy at XOZ plane under steady and dynamic conditions

Fig.14 The mean turbulent viscosity of impact axis under steady and dynamic conditions

Fig.15 The variation of mean pressure on impact axis under steady and dynamic conditions

Fig.16 The spectrum diagram of the stagnation point velocity under steady and dynamic conditions

Fig.17 The power spectrum of stagnation point velocity under steady and dynamic conditions

Fig.18 The average velocity of stagnation point under different conditions

Fig.19 The movement speed of impact surface under different conditions

Fig.20 The turbulence intensity of impact axis under different conditions

Fig.21 The mean turbulent kinetic energy on XOZ plane in one cycle

References 31

1	伍沅. 撞击流——原理·性质·应用[M]. 北京: 化学工业出版社, 2006: 3-12.
	Wu Y. Impinging Streams: Fundamental, Properties and Applications[M]. Beijing: Chemical Industry Press, 2006: 3-12.
2	Hu H, Chen Z M, Jiao Z. Characterization of micro-mixing in a novel impinging streams reactor[J]. Frontiers of Chemical Engineering in China, 2009, 3(1): 58-64.
3	Wu Y, Zhou Y X, Guo J, et al. Features of impinging streams intensifying processes and their applications[J]. International Journal of Chemical Engineering, 2010, 2010: 1-16.
4	张建伟, 闫宇航, 沙新力, 等. 撞击流强化混合特性及用于制备超细粉体研究进展[J]. 化工进展, 2020, 39(3): 824-833.
	Zhang J W, Yan Y H, Sha X L, et al. Advances on impinging stream intensification mixing mechanism for preparing ultrafine powders[J]. Chemical Industry and Engineering Progress, 2020, 39(3): 824-833.
5	Yue S, Liu X Q. Study of the drying characteristics in an asymmetric impinging stream reactor[J]. Chemical Papers, 2021, 75(8): 4355-4370.
6	方书起, 张欣悦, 李思齐, 等. 撞击流式反应器内水合物法分离沼气中CO₂研究[J]. 化工学报, 2020, 71(5): 2099-2108.
	Fang S Q, Zhang X Y, Li S Q, et al. Investigation on separation of CO₂ from biogas by hydrate method in impinging stream reactor [J]. CIESC Journal, 2020, 71(5): 2099-2108.
7	Liu Z W, Zhang Q C, Wen L X, et al. Preparation of ultrafine manganese dioxide by micro-impinging stream reactors and its electrochemical properties[J]. The Canadian Journal of Chemical Engineering, 2016, 94(3): 461-468.
8	Chen Z Y, Liu Y, Zhang Y Z, et al. Ultrafine layered graphite as an anode material for lithium ion batteries[J]. Materials Letters, 2018, 229: 134-137.
9	许鑫磊. 撞击流反应器内吞噬流机理实验研究与数值模拟[D]. 上海: 华东理工大学, 2019.
	Xu X L. Experimental and numerical study on engulfment regime of impinging jets reactors[D]. Shanghai: East China University of Science and Technology, 2019.
10	聂傲, 王智邈, 韩敬, 等. 不等径撞击流反应器流动与微观混合特性的研究[J]. 中国科学: 化学, 2018, 48(6): 648-657.
	Nie A, Wang Z M, Han J, et al. Experimental investigation of flow and reacting characteristics in asymmetric confined impinging jets reactor[J]. Scientia Sinica (Chimica), 2018, 48(6): 648-657.
11	张建伟, 张学良, 冯颖, 等. 浸没对置撞击流的液相混合行为研究[J]. 高校化学工程学报, 2016, 30(2): 311-317.
	Zhang J W, Zhang X L, Feng Y, et al. Study on liquid mixing behavior within a submerged impinging stream mixer[J]. Journal of Chemical Engineering of Chinese Universities, 2016, 30(2): 311-317.
12	Parham K, Esmaeilzadeh E, Atikol U, et al. A numerical study of turbulent opposed impinging jets issuing from triangular nozzles with different geometries[J]. Heat and Mass Transfer, 2011, 47(4): 427-437.
13	屠功毅, 李伟锋, 黄国峰, 等. 平面撞击流偏斜振荡的实验研究与大涡模拟[J]. 物理学报, 2013, 62(8): 084704.
	Tu G Y, Li W F, Huang G F, et al. Large-eddy simulation and experimental study of deflecting oscillation of planar opposed jets[J]. Acta Physica Sinica, 2013, 62(8): 084704.
14	杜敏, 黄彬, 卢麒丞, 等. 撞击流内液滴碰撞后续发展行为[J]. 化工学报, 2018, 69(5): 2023-2031.
	Du M, Huang B, Lu Q C, et al. Subsequent development of collided droplets in impinging streams[J]. CIESC Journal, 2018, 69(5): 2023-2031.
15	屠功毅, 李伟锋, 黄国峰, 等. 平面撞击流偏斜振荡影响因素的大涡模拟[J]. 化工学报, 2013, 64(7): 2353-2359.
	Tu G Y, Li W F, Huang G F, et al. Large-eddy simulation of influencing factors of deflecting oscillation of planar opposed jets[J]. CIESC Journal, 2013, 64(7): 2353-2359.
16	Zhang J, Liu Y Z, Luo Y. The turbulent behavior of novel free triple-impinging jets with large jet spacing by means of particle image velocimetry[J]. Chinese Journal of Chemical Engineering, 2016, 24(6): 757-766.
17	Tsaoulidis D, Angeli P. Liquid-liquid dispersions in intensified impinging-jets cells[J]. Chemical Engineering Science, 2017, 171: 149-159.
18	张建伟, 王诺成, 冯颖, 等. 基于PLIF的水平三向撞击流径向流型的研究[J]. 高校化学工程学报, 2016, 30(3): 723-729.
	Zhang J W, Wang N C, Feng Y, et al. Study on radial stream patterns in three-jet impinging stream mixers using planar laser induced fluorescence[J]. Journal of Chemical Engineering of Chinese Universities, 2016, 30(3): 723-729.
19	Zhang J W, Ding C W, Dong X, et al. Experimental study on the flow field characteristics of the two-layer impinging stream mixer[J]. The Canadian Journal of Chemical Engineering, 2021, 99(12): 2748-2759.
20	刘雪晴, 王奎, 鲁录义. 改进型撞击流反应器流动特性研究[J]. 现代机械, 2017(5): 1-6.
	Liu X Q, Wang K, Lu L Y. Research on flow characteristics of an improved impinging stream reactor[J]. Modern Machinery, 2017(5): 1-6.
21	Liu X Q, Yue S, Lu L Y, et al. Experimental and numerical studies on flow and turbulence characteristics of impinging stream reactors with dynamic inlet velocity variation[J]. Energies, 2018, 11(7): 1717.
22	刘雪晴. 动态非对称撞击流反应器流动特性研究[D]. 武汉: 华中科技大学, 2019.
	Liu X Q. Study on flow characteristics of dynamic asymmetric impinging stream reactor[D]. Wuhan: Huazhong University of Science and Technology, 2019.
23	Liu X Q, Yue S, Lu L Y, et al. Flow simulation and experimental study of a dynamic asymmetric impinging stream[J]. Numerical Heat Transfer, Part A: Applications, 2018, 73(12): 863-880.
24	刘娇. 动态混合器混合性能的理论及实验研究[D]. 北京: 北京化工大学, 2016.
	Liu J. Theoretical and experimental studies on mixing performance of the dynamic mixer[D]. Beijing: Beijing University of Chemical Technology, 2016.
25	张建伟, 马繁荣, 张志刚, 等. 双组水平喷嘴撞击流反应器流场POD分析[J]. 化工学报, 2018, 69(7): 2916-2925.
	Zhang J W, Ma F R, Zhang Z G, et al. POD analysis of flow field in horizontal two-group nozzle impinging stream reactor[J]. CIESC Journal, 2018, 69(7): 2916-2925.
26	杨秀娜, 姜阳, 阮宗琳, 等. 生物柴油生产过程撞击反应器的停留时间分布研究[J]. 化学工程, 2017, 45(2): 50-55.
	Yang X N, Jiang Y, Ruan Z L, et al. Residence time distribution of impinging reactor for biodiesel production[J]. Chemical Engineering (China), 2017, 45(2): 50-55.
27	张建伟, 尚盼龙, 闫俊杰, 等. 水平对置双向撞击流混合器的混合效果[J]. 过程工程学报, 2017, 17(5): 959-964.
	Zhang J W, Shang P L, Yan J J, et al. Mixing effect in two horizontal opposed impinging stream mixer[J]. The Chinese Journal of Process Engineering, 2017, 17(5): 959-964.
28	张建伟, 施博文, 冯颖, 等. 浸没状态下液-液两相水平对撞浓度场的数值模拟[J]. 过程工程学报, 2018, 18(1): 57-62.
	Zhang J W, Shi B W, Feng Y, et al. Numerical simulation of concentration field of liquid-liquid two-phase impinging streams in submerged condition[J]. The Chinese Journal of Process Engineering, 2018, 18(1): 57-62.
29	Moffatt H K, Tsinober A, 程屏芬. 层流和湍流中的螺旋度[J]. 力学进展, 1993, 23(1): 69-85.
	Moffatt H K, Tsinober A, Cheng P F. Helicity in laminar and turbulent flow [J]. Advances in Mechanics, 1993, 23(1): 69-85.
30	Zhang J W, Yan J J, Dong X, et al. Experimental study on turbulence properties in the dual nozzle opposed impinging stream mixer[J]. The Canadian Journal of Chemical Engineering, 2017, 95(3): 550-558.
31	沙新力. 双组分层式撞击流混合器浓度场的Hilbert-Huang变换分析[D]. 沈阳: 沈阳化工大学, 2020.
	Sha X L. Hilbert-Huang transform analysis of concentration field of two-component layered impinging stream mixer[D]. Shenyang: Shenyang University of Chemical Technology, 2020.

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