Measurement of Gas-Liquid Two-Phase Flow in Draft Tube

doi:10.16183/j.cnki.jsjtu.2023.091

Abstract

Abstract:

The limitation of traditional measurement technology in gas-liquid two-phase flow measurement is broken through.The liquid velocity field and vortex rope morphology from two vertical directions were measured synchronically by using particle image velocimetry and pulsed shadowgraphy technique. Experimental measurements show that the vortex rope in the draft tube presents three kinds of unstable circulation flow evolution, single spiral, double spiral, and overstocked rupture. When a single spiral vortex rope is partially split into two, it becomes a double spiral vortex rope. When the local spiral rise angle of a single spiral vortex rope decreases, it becomes an overstocked rupture. When there is a single spiral vortex rope in the draft tube, the vortex rope rotates precession around the central axis along with the liquid main flow, and the flow is divided into two parts, the outer main flow zone and the central stagnation zone, according to the axial velocity. The shear layer between the main flow zone and the stagnation zone rolls up to form several vortices. The position of liquid vortices determines the spatial morphology of the spiral vortex rope.

Key words: vortex rope, gas-liquid two-phase flow, particle image velocimetry, pulsed shadowgraphy, 3D reconstruction

CLC Number:

TK730.1

LI Jinfeng, CHEN Wuguang, ZHANG Zhengchuan, XU Yongliang, LI Kaiying, YIN Junlian, WANG Dezhong. Measurement of Gas-Liquid Two-Phase Flow in Draft Tube[J]. Journal of Shanghai Jiao Tong University, 2024, 58(8): 1188-1200.

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References 15

[1]	周星, 伍鹤皋, 苏凯. 混流式水轮机轴向水推力研究综述和讨论[J]. 水利学报, 2019, 50(10): 1242-1252.
	ZHOU Xing, WU Hegao, SU Kai. Overview and discussion on hydraulic axial thrust in Francis turbine research[J]. Journal of Hydraulic Engineering, 2019, 50(10): 1242-1252.
[2]	陈秋华, 张晓曦, 何思源. 初始运行工况对水泵水轮机飞逸过渡过程水力特性的影响[J]. 水利学报, 2020, 51(7): 858-868.
	CHEN Qiuhua, ZHANG Xiaoxi, HE Siyuan. Influence of the initial working condition on the hydraulic performance of the pump-turbine during runaway transient scenario[J]. Journal of Hydraulic Engineering, 2020, 51(7): 858-868.
[3]	周勤, 夏林生, 张春泽, 等. 水泵水轮机甩负荷过渡过程中的压力脉动和转轮受力[J]. 水利学报, 2018, 49(11): 1429-1438.
	ZHOU Qin, XIA Linsheng, ZHANG Chunze, et al. Transient pressure fluctuations and runner loadings of a model pump-turbine during a load rejection process[J]. Journal of Hydraulic Engineering, 2018, 49(11): 1429-1438.
[4]	KUMAR S, CERVANTES M J, GANDHI B K. Rotating vortex rope formation and mitigation in draft tube of hydro turbines-A review from experimental perspective[J]. Renewable and Sustainable Energy Reviews, 2021, 136: 110354.
[5]	NICOLET C, ZOBEIRI A, MARUZEWSKI P, et al. Experimental investigations on upper part load vortex rope pressure fluctuations in francis turbine draft tube[J]. International Journal of Fluid Machinery and Systems, 2011, 4(1): 179-190.
[6]	SKRIPKIN S, TSOY M, SHTORK S, et al. Comparative analysis of twin vortex ropes in laboratory models of two hydro-turbine draft-tubes[J]. Journal of Hydraulic Research, 2016, 54(4): 450-460.
[7]	ALEKSEENKO S V, KUIBIN P A, SHTORK S I, et al. Vortex reconnection in a swirling flow[J]. JETP Letters, 2016, 103(7): 455-459.
[8]	GOYAL R, GANDHI B K, CERVANTES M J. PIV measurements in Francis turbine—A review and application to transient operations[J]. Renewable and Sustainable Energy Reviews, 2018, 81: 2976-2991.
[9]	LAI X D, LIANG Q W, YE D X, et al. Experimental investigation of flows inside draft tube of a high-head pump-turbine[J]. Renewable Energy, 2019, 133: 731-742.
[10]	GOYAL R, CERVANTES M J, GANDHI B K. Vortex rope formation in a high head model francis turbine[J]. Journal of Fluids Engineering, 2017, 139(4): 041102.
[11]	TRIDON S, CIOCAN G D, BARRE S, et al. 3D time-resolved PIV measurement in a francis turbine draft tube[C]// 24th Symposium on Hydraulic Machinery and Systems. Fos Do Iguassu, Brazil: IAHR, 2008.
[12]	ILIESCU M S, CIOCAN G D, AVELLAN F. Analysis of the cavitating draft tube vortex in a francis turbine using particle image velocimetry measurements in two-phase flow[J]. Journal of Fluids Engineering, 2008, 130(2): 146-157.
[13]	孙龙刚, 郭鹏程, 罗兴锜. 水轮机尾水管涡带压力脉动同步及非同步特性研究[J]. 农业机械学报, 2019, 50(9): 122-129.
	SUN Longgang, GUO Pengcheng, LUO Xingqi. Investigation on synchronous and asynchronous characteristics of pressure fluctuations towards precessing vortex rope in francis turbine draft tube[J]. Transactions of the Chinese Society for Agricultural Machine-ry, 2019, 50(9): 122-129.
[14]	SKRIPKIN S G, KUIBIN P A, SHTORK S I. The effect of air injection on the parameters of swirling flow in a Turbine-99 draft tube model[J]. Technical Physics Letters, 2015, 41(7): 638-640.
[15]	LI Y F, BLOIS G, KAZEMIFAR F, et al. A particle-based image segmentation method for phase separation and interface detection in PIV images of immiscible multiphase flow[J]. Measurement Science and Technology, 2021, 32(9): 095208.

序号	Q_l×10³/ (m³·s^-1)	Q_g/(m³·s^-1)	Re×10^-5	β/%
1	2.01	3.33×10^-6	0.57	0.17
2	2.01	6.66×10^-6	0.57	0.33
3	2.91	3.33×10^-6	0.82	0.11
4	2.91	6.66×10^-6	0.82	0.23
5	2.91	1.00×10^-5	0.82	0.34
6	2.91	1.33×10^-5	0.82	0.46
7	2.91	1.66×10^-5	0.82	0.57
8	3.52	6.66×10^-6	1.00	0.19
9	3.52	1.00×10^-5	1.00	0.28
10	4.31	6.66×10^-6	1.23	0.15
11	4.31	1.00×10^-5	1.23	0.23
12	4.98	1.00×10^-5	1.41	0.20