Fluid flow in rectangular helical channels with vortex generator

doi:10.3969/j.issn.0438-1157.2014.10.013

Abstract

Abstract: The flow field of rectangular helical channel with triangle winglet pair vortex generator was measured experimentally. The curvature of the helical channel was 0.05. The experimental data are in good agreement with the calculated data. The evolution of vorticity in the helical channel and the influence of Reynolds number and the curvature on the effective influence distance of vortex generator were investigated by numerical method. The results show that, two extra vortices in common-flow-down type emerge near the inner wall in the rectangular cross section of the helical channel with triangle winglet pair vortex generator. The values of extra vorticity are 2.0-2.8 times those of the original vorticity. The effective influence distance of the vortex generator increases with the decrease of curvature and the increase of Reynolds number. It can reach 79 times of the height of the vortex generator with the curvature of 0.05, attack angle of 10° and Reynolds number of 5370.

Key words: computational fluid dynamics, vortex generator, hydrodynamics, flow, helical channel

摘要： 对安装三角翼型涡发生器的曲率为0.05的矩形截面螺旋通道内的流场进行了实验测量，并将测量值与模拟值进行比较，二者吻合较好。利用数值模拟方法研究了矩形截面螺旋通道内涡量的演变过程，研究了曲率及Reynolds数对涡发生器有效作用距离的影响。结果表明，安装三角翼型涡发生器后，矩形截面内靠近内壁处新出现了两个common-flow-down型的二次涡，新出现的额外涡量的极值为原有涡量的2.0~2.8倍。Reynolds数越大，曲率越小，涡发生器的有效作用距离越长。当曲率为0.05，迎流角为10°，Reynolds数为5370时，其值可达翼高的79倍。

关键词: 计算流体力学, 涡发生器, 流体动力学, 流动, 螺旋通道

CLC Number:

TQ021.1

ZHANG Li, LI Jiaqi, ZHANG Chunmei, WANG Cuihua, WU Jianhua. Fluid flow in rectangular helical channels with vortex generator[J]. CIESC Journal, 2014, 65(10): 3838-3845.

张丽, 李佳其, 张春梅, 王翠华, 吴剑华. 安装涡发生器的矩形截面螺旋通道内流体流动[J]. 化工学报, 2014, 65(10): 3838-3845.

References 23

[1]	Zhang L, Guo H M, Wu J H, Du W J. Compound heat transfer enhancement for shell side of double-pipe heat exchanger by helical fins and vortex generators [J]. Heat and Mass Transfer, 2012, 48 (7): 1113-1124
[2]	Zhang Li (张丽), Tian Mimi (田密密), Wu Jianhua (吴剑华). Heat transfer enhancement for shell side of double-pipe heat exchanger with pin fins and helical fins [J]. CIESC Journal (化工学报), 2010, 61 (3): 587-593
[3]	Sinha A, Raman K A, Chattopadhyay H, Biswas G. Effects of different orientations of winglet arrays on the performance of plate-fin heat exchangers [J]. Int.J.Heat Mass Transfer, 2013, 57 (1): 202-214
[4]	Min C H, Qi C Y, Wang E Y, Tian L T, Qin Y J. Numerical investigation of turbulent flow and heat transfer in a channel with novel longitudinal vortex generators [J]. Int.J.Heat Mass Transfer, 2012, 55: 7268-7277
[5]	Zhou G B, Ye Q L. Experimental investigations of thermal and flow characteristics of curved trapezoidal winglet type vortex generators [J]. Appl.Therm.Eng., 2012, 37: 241-248
[6]	Fiebig M, Kallweit P, Mitra N, Tiggelbeck S. Heat transfer enhancement and drag by longitudinal vortex generators in channel flow [J]. Exp.Therm.Fluid Sci., 1991, 4 (1): 103-114
[7]	Zhu J X, Mitra N K, Fiebig M. Effects of longitudinal vortex generators on heat transfer and flow loss in turbulent channel flows [J]. Int.J.Heat Mass Transfer, 1993, 36 (9): 2339-2347
[8]	Fiebig M. Embedded vortices in internal flow: heat transfer and pressure loss enhancement [J]. Int.J.Heat Mass Transfer, 1995, 16 (5): 376-388
[9]	Biswas G, Chattopadhyay H. Heat transfer in a channel with built-in wing-type vortex generators [J]. Int.J.Heat Mass Transfer, 1992, 35 (4): 803-814
[10]	Biswas G, Torii K, Fujii D, Nishino K. Numerical and experimental determination of flow structure and heat transfer effects of longitudinal vortices in a channel flow [J]. Int.J.Heat Mass Transfer, 1996, 39 (16): 3441-3451
[11]	Fiebig M. Vortices, generators and heat transfer [J]. Trans IChemE (A), 1998, 76 (2): 108-123
[12]	Akcayoglu A. Flow past confined delta-wing type vortex generators [J]. Exp.Therm.Fluid Sci., 2011, 35 (1): 112-120
[13]	Min Chunhua (闵春华), Yang Lixin (杨立新), Qi Chengying (齐承英), Dong Jiangfeng (董江峰). PIV measurement of flow field in a rectangular channel with longitudinal vortex generators [J]. Journal of Hebei University of Technology (河北工业大学学报), 2011, 40 (6): 59-62
[14]	Eibeck P A, Eaton J K. Heat transfer effects of a longitudinal vortex embedded in a turbulent boundary layer [J]. Heat Transfer, 1987, 109 (1): 16-24
[15]	Song Xiangeng (宋宪耕), Song Donghui (宋东辉), Li Xuanyou (李选友), Wang Zhaojie (王肇杰), Du Guangsheng (杜广生), Qiu Liejun (裘烈钧). Experimental study on mechanism of heat transfer in turbulence boundary layer of rectangular channel with vortex [J]. Journal of Astronautics (宇航学报), 1996, 17 (2): 70-75
[16]	Huang Jun (黄军), Huang Yanping (黄彦平), Ma Jian (马建), Zhou Na (周娜), Wang Qiuwang (王秋旺). Effective influence distance of longitudinal vortex in narrow rectangular channel [J]. Journal of Engineering Thermophysics (工程热物理学报), 2010, 31 (2): 299- 301
[17]	Wang Haigang (王海刚), Huang Jun (黄军), Chen Qiuyang (陈秋炀), Zeng Min (曾敏), Wang Qiuwang (王秋旺). Numerical optimization of space between LVGs in narrow rectangular channel [J]. Journal of Engineering Thermophysics (工程热物理学报), 2009, 30 (1): 135-137
[18]	Zhang Li (张丽), Xing Yanwei (邢彦伟), Wu Jianhua (吴剑华). Fluid flow characteristic in helical duct with rectangular cross section [J]. CIESC Journal (化工学报), 2010, 61 (5): 1089-1096
[19]	Zhang L, Du W J, WU J H, Li Y X. Fluid flow characteristics for shell side of double-pipe heat exchanger with helical fins and pin fins [J]. Exp.Therm.Fluid Sci., 2012, 36 (1): 30-43
[20]	Zhang Li (张丽), Xie Caipeng (谢彩朋), Li Yaxia (李雅侠), Wu Jianhua (吴剑华). The compound heat transfer enhancement with helical fins and vortex generators for the shells at different curvature [J]. CIESC Journal (化工学报), 2013, 64 (9): 3198-3205
[21]	Bolinder C J. Flow visualization and LDV measurements of laminar flow in a helical square ducts with finite pitch [J]. Exp.Therm.Fluid Sci., 1995, 11 (4): 348-363
[22]	You D, Wang M, Mittal R, Moin P. Large-eddy simulations of longitudinal vortices embedded in a turbulent boundary layer [J]. AIAA Journal, 2006, 44 (12): 3032-3039
[23]	Hüttl T J, Friedrich R. Influence of curvature and torsion on turbulent flow in helically coiled pipes [J]. Int.J.Heat Fluid Flow, 2000, 21 (1): 345-353