Heat transfer enhancement mechanism of jet longitudinal vortex generator in helical channel with rectangular cross section

doi:10.11949/0438-1157.20190286

Abstract

Abstract:

This study proposed to use a jet longitudinal vortex generator (JVG) to enhance heat transfer capability of fluid in the helical channel. Fluid flow characteristics in the helical channel with rectangular cross-section and installed with a JVG were measured by a 3D Laser Doppler Velocimeter (LDV). The curvature of helical channel is δ=0.134. The experimental results were in good agreement with the simulated results. The evolution process of the composite secondary vortices in the helical channel with a JVG and the attenuation process of the jet in the helical channel were obtained. The results show that the impact and entrainment of the jet changes the structure of the common-flow-up (CFU) vortices in the smooth helical channel. And a pair of common-flow-down (CFD) vortices is formed in the initial stage of jet. With the development of the flow in the helical channel, the CFD vortices undergo a process of rapidly producing, slowly decomposing and gradually dissipating. When the speed ratio of the jet stream to the main stream is between 1.48 and 4.02, the effect of jet can reach a distance of 40—74 times d _h along the mainstream direction in the helical channel. Here d _h is the equivalent diameter of helical channel. The effect of JVG improves the synergy between the velocity fields and the temperature fields in the helical channel, thus heat transfer enhancement can be achieved. Within the scope of the study, the average Nusselt number of the heat exchange wall is increased by 28% to 248% relative to the single spiral channel.

Key words: helical channel, jet, flow, heat transfer, numerical simulation, field synergy

摘要：

提出利用射流式涡流发生器(JVG)强化螺旋通道内流体的换热。采用三维激光多普勒测速仪(LDV)测量了曲率为0.134并安装了JVG的矩形截面螺旋通道内流体的流动特性，实验结果与数值模拟结果吻合较好。获得了安装JVG的螺旋通道内复合二次涡旋的演变规律以及射流在螺旋通道内的衰减过程。结果表明，射流的冲击和卷吸作用改变了单一螺旋通道内背离壁面 (common-flow-up， CFU) 结构的离心二次涡旋，在射流的起始段形成了一对冲向壁面(common-flow-down， CFD)结构的二次涡旋。随着流动的发展，CFD涡旋经历了快速形成、缓慢分解并逐渐耗散的过程。射流速比ε _j在1.48~4.02范围内时，射流在螺旋通道内沿主流方向的作用距离可达40d _h~74d _h（d _h为螺旋通道当量直径）。射流提高了通道换热壁面附近处速度场与温度场的协同性，实现了换热强化。研究范围内，换热壁面平均Nusselt数的最大值相对于单一螺旋通道提高了28%~248%。

关键词: 螺旋通道, 射流, 流动, 传热, 数值模拟, 场协同

CLC Number:

TK 124

Yaxia LI, Xia WANG, Jing ZHANG, Chunmei ZHANG, Bin GONG, Jianhua WU. Heat transfer enhancement mechanism of jet longitudinal vortex generator in helical channel with rectangular cross section[J]. CIESC Journal, 2019, 70(8): 2961-2970.

李雅侠, 王霞, 张静, 张春梅, 龚斌, 吴剑华. 射流式涡发生器强化矩形螺旋通道内流体换热机理[J]. 化工学报, 2019, 70(8): 2961-2970.

Figures/Tables 13

Fig.1 Helical channel mounted with JVG

Fig.2 Schematic diagram of experimental system

Fig.3 Picture of experimental device

Fig.4 Comparison of velocities between simulated and experimental values at ε j=2.96

Fig.5 Diagram of section position

Fig.6 Flow fields in different cross sections at ε j=1.48(left side of cross section is inner wall of helical channel)

Fig.7 Evolution of composite secondary flow fields at ε j=1.48

Fig.8 Distribution of w′ on surface 2

Fig.9 Change of f along flow direction

Fig.10 Distribution of Nu local on heated wall at ε j=1.48

Fig.11 Change of (Nu local)m along main flow direction

Fig.12 Comprehensive enhanced heat transfer factor JF

Fig.13 Cloud map of α in surface 1 cross section at θ 1=5°

References 31

1	林清宇, 刘鹏辉, 冯振飞, 等 . 螺旋通道内流体流动与传热特性研究进展[J]. 科学通报, 2017, 62(25): 2931-2940.
	Lin Q Y , Liu P H , Feng Z F , et al . A review on fluid flow and heat transfer in helical channel [J]. Chinese Science Bulletin, 2017, 62(25): 2931-2940.
2	陈迁乔, 钟秦 . 螺旋管内对流传质场协同强化模拟[J]. 化工学报, 2012, 63(12): 3764-3770.
	Chen Q Q , Zhong Q . Simulation on field synergy enhancement for convective mass transfer in helical tube[J]. CIESC Journal, 2012, 63(12): 3764-3770.
3	张静, 张艳秋, 吴剑华 . 螺距和搭接对螺旋半管夹套强化传热的影响[J]. 过程工程学报, 2018, 17(4): 697-703.
	Zhang J , Zhang Y Q , Wu J H . Effect of varying pitch and overlap scale on enhanced heat transfer of half-coil jackets[J]. The Chinese Journal of Process Engineering, 2018, 17(4): 697-703.
4	李雅侠, 王航, 吴剑华 . 螺旋半圆管夹套内充分发展层流流动与换热特性[J]. 化工学报, 2010, 61(11): 2796-2803.
	Li Y X , Wang H , Wu J H . Fully developed laminar flow and heat transfer characteristics in half-coil jackets[J]. CIESC Journal, 2010, 61(11): 2796-2803.
5	Li Y X , Wu J H , Zhang L , et al . Comparison of fluid flow and heat transfer behavior in outer and inner half coil jackets and field synergy analysis[J]. Appl. Therm. Eng., 2011, 31(6): 3078-3083.
6	黄军, 王令, 王秋旺, 等 . 纵向涡发生器传热强化的研究进展[J]. 动力工程, 2007, 27(2): 211-217.
	Huang J , Wang L , Wang Q W , et al . Research process concerning enhancement of heat transfer by longitudinal vortex generators[J]. J. Power Eng., 2007, 27(2): 211-217.
7	黄红波, 陆芳 . 涡流发生器应用发展进展[J]. 武汉理工大学学报(交通科学与工程版), 2011, 35(3): 611-614, 618.
	Huang H B , Lu F . Research progress of vortex generator application[J]. J. Wuhan Univ. Tech. (Transp. Sci. Eng.), 2011, 35(3): 611-614, 618.
8	Li Y X , Wang X , Zhang J , et al . Comparison and analysis of the arrangement of delta winglet pair vortex generators in a half coiled jacket for heat transfer enhancement [J]. Int. J. Heat Mass Trans., 2019, 129(2): 287-298.
9	李雅侠, 张腾, 张春梅, 等 . 翼型涡发生器对半圆形螺旋通道的换热强化机理[J]. 化工学报, 2016, 67(5): 1814-1821.
	Li Y X , Zhang T , Zhang C M , et al . Enhanced heat transfer mechanism of winglet vortex generator in helical channel with semicircular cross section[J]. CIESC Journal, 2016, 67(5): 1814-1821.
10	Zhang L , Shang B J , Meng H B , et al . Effects of the arrangement of triangle-winglet-pair vortex generators on heat transfer performance of the shell side of a double-pipe heat exchanger enhanced by helical fins[J]. Heat Mass Transfer, 2017, 53(1): 127-139.
11	管小荣, 徐诚 . 微型射流涡流发生器对边界层控制的数值研究[J]. 工程力学, 2009, 26(4): 214-220, 245.
	Guan X R , Xu C . Numerical investigation of boundary-layer control using minute jet vortex generator[J]. Eng. Mech., 2009, 26(4): 214- 220, 245.
12	胡昊, 李新凯, 王晓东, 等 . 基于DES射流式涡发生器数值模拟研究[J]. 太阳能学报, 2015, 36(7): 1671-1677.
	Hu H , Li X K , Wang X D , et al . Numerical simulation of vortex generator jets based on DES[J]. Acta Energi. Sin., 2015, 36(7): 1672-1676.
13	杨婧, 王小军, 杨祺 . 冲击射流换热研究进展[J]. 真空与低温, 2018, 24(4): 217- 222.
	Yang J , Wang X J , Yang Q . Advances in jet impinging heat transfer[J]. Vacuum Cryogenics, 2018, 24(4): 217-222.
14	Chaudhari M , Puranik B , Agrawal A . Heat transfer characteristics of synthetic jet impingement cooling[J]. Int. J Heat Mass Trans., 2010, 53(5/6): 1057-1069.
15	刘明阳, 常士楠, 杨波 . 稳态与瞬态冲击射流换热性能实验对比[J]. 推进技术, 2019, 40(1): 99-103.
	Liu M Y , Chang S N , Yang B . Experimental comparison of heat transfer performance between steady and transient impinging jet[J]. Journal of Propulsion Technology, 2019, 40(1): 99-103.
16	Nakabe K , Suzuki K , Inaoka K , et al . Generation of longitudinal vortices in internal flows with an inclined impinging jet and enhancement of target plate heat transfer[J]. Int. J. Heat Fluid, 1998, 19(5): 573-581.
17	周冬, 任建勋 . 射流纵向涡强化换热的数值模拟[J]. 清华大学学报(自然科学版), 2004, 44(11): 1520-1523.
	Zhou D , Ren J X . Numerical simulation of heat transfer enhancement by jet-induced longitudinal vortices[J]. J. Tsinghua Univ. (Sci. & Tech.), 2004, 44(11): 1520-1523.
18	Clerx N , Geld C W M V D , Kuerten J G M . Turbulent stresses in a direct contact condensation jet in cross-flow in a duct with implications for particle break-up[J]. Int. J Heat Mass Tran., 2013, 66: 684-694.
19	Yang Y T , Wang Y X . Three-dimensional numerical simulation of an inclined jet with cross-flow[J]. Int. JHeat Mass Trans., 2005, 48(19/20): 4019–4027.
20	Bolinder C J , Suneden B . Flow visualization and LDV measurements of laminar flow in a helical square duct with finite pitch[J]. Exp. Therm. Fluid Sci., 1995, 11(4): 348-363.
21	杨世铭, 陶文铨 . 传热学[M]. 4版. 北京: 高等教育出版社, 2006: 229-300.
	Yang S M , Tao W Q . Heat Transfer[M]. 4th ed. Beijing: Higher Education Press, 2006: 229-300.
22	陶文铨 . 数值传热学[M]. 2版, 西安: 西安交通大学出版社, 2001: 332-430.
	Tao W Q . Numerical Heat Transfer[M]. 2nd ed.Xi an: Xi an Jiaotong University Press, 2001: 332-430.
23	黄卫星, 陈文梅 .工程流体力学[M]. 北京: 化学工业出版社, 2001: 127-128.
	Huang W X , Chen W M . Engineering Fluid Mechanics[M]. Beijing: Chemical Industry Press, 2001: 127-128.
24	张丽, 李佳奇, 张春梅, 等 . 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.
	Zhang L , Li J Q , Zhang C M , et a1 ．Fluid flow in rectangular helical channel with vortex generator[J]. CIESC Journal, 2014, 65(10): 3838-3845.
25	董志勇 . 射流力学[M]. 北京: 科学出版社, 2005: 225.
	Dong Z Y . Jet Mechanics[M]. Beijing: Science Press, 2005: 225.
26	Biswas G , Chattopadhyay H , Sinha A . Augmentation of heat transfer by creation of streamwise longitudinal vortices using vortex generators[J]. Heat Transfer Engineering, 2012, 33(4/5): 406-424.
27	李国能, 林江, 李凯, 等 . 横向射流中心轨迹和扩展宽度[J]. 化工学报, 2011, 62(1): 66-70.
	Li G N , Lin J , Li K , et al . Central trajectory and spread width in transverse jet[J]. CIESC Journal, 2011, 62(1): 66-70.
28	王海军, 陈听宽, 罗毓珊, 等 . T型三通管横向射流流动与传热实验研究[J]. 热能动力工程, 2002, 17(97): 14-17.
	Wang H J , Chen T K , Luo Y S , et al . Experimental study of transverse jet flow and heat transfer of a T-shaped three-way pipe[J]. J.Eng. Therm. Energy Power, 2002, 17(97): 14-17.
29	Anupam S , Himadri C , Ashwin K I . Enhancement of heat transfer in a fin-tube heat exchanger using rectangular winglet type vortex generators[J]. Int. J. Heat Mass Trans., 2016, 101: 667-681.
30	San J Y , Huang C H , Shu M H . Impingement cooling of confined circular air jet [J]. Int. J. Heat Mass Trans., 1997, 40(6): 1355-1364.
31	Guo Z Y , Tao W Q , Shah R K . The field synergy(coordination) principle and its applications in enhancing single phase convective heat transfer[J]. Int. J. Heat Mass Trans., 2005, 48: 1797-1807.

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