电场作用下矩形微槽群润湿特性数值分析

doi:10.11949/j.issn.0438-1157.20180523

摘要/Abstract

摘要：

以预测电场作用下竖直矩形微槽群热沉内液体润湿特性为目的，基于自适应理论，建立一维轴向模型，研究了电场强度、热通量以及微槽尺寸对润湿特性的影响。结果表明：电场作用下润湿长度随热通量增加逐渐降低。当热通量较低时，电场强度对润湿长度的强化较大，但随着热通量的增大强化程度减弱。电场强度对矩形微槽群热沉适应长度的强化较小，而对于边角流动区域长度的强化较为显著。电场作用下润湿长度随槽深和槽宽的增加分别呈增加和下降的趋势。与较小槽深槽宽相比，当槽尺寸较大时，电场强度对微槽内液体润湿强化更为显著。

关键词: 微通道, 传热, 数值分析, 电场, 矩形微槽群热沉, 润湿长度

Abstract:

A one dimensional semi analysis model was developed based on accommodation theory to study the effect of electric field on liquid wetting characteristics in vertical rectangular capillary microgrooves heat sinks. The effects of electric field intensity, heat flux and microgrooves dimensions on liquid wetting characteristics are investigated. The results show that the electric field can be utilized to improve the wetting length of liquid in microgrooves heat sinks. The wetting length decreases with heat flux under the electric field effect. When the heat flux is relatively small, the enhancement of the wetting length due to the electric field intensity is higher, yet the enhancement due to the electric field decreases with the heat flux. The accommodation length and the corner flow length under the action of electric field are studied and compared. Both the accommodation length and the corner flow length increase with the increasing electric field intensity yet the enhancement in corner flow length is more distinguished. Since the liquid film in the corner flow stage is thinner than the accommodation stage, according to thin film theory, the enhancement of the corner flow length is important to the heat transfer enhancement of the rectangular microgrooves. Effects of microgroove dimensions on wetting length under electric field effect are considered. The length of wetting under the action of electric field increases and decreases with the increase of groove depth and groove width. Compared with microgrooves with smaller depth and width, when the groove size is larger, the electric field strength is more significant for with the liquid wetting strengthening in the microgrooves.

Key words: microchannels, heat transfer, numerical analysis, electric field, rectangular microgrooves heat sink, wetting length

中图分类号:

TQ021.3

于樱迎, 唐瑾晨, 胡学功. 电场作用下矩形微槽群润湿特性数值分析[J]. 化工学报, 2018, 69(10): 4216-4223.

YU Yingying, TANG Jinchen, HU Xuegong. Theoretical analysis of wetting characteristics in rectangular microgrooves under electric field[J]. CIESC Journal, 2018, 69(10): 4216-4223.

参考文献 30

[1]	胡学功, 唐大伟. 竖直毛细微槽群热沉中蒸发液体的干涸特性[J]. 化工学报, 2007, 58(3):575-580. HU X G, TANG D W. Dryout characteristics of evaporating liquid in vertical capillary microgrooves heat sink[J]. Journal of Chemical Industry and Engineering (China),2007, 58(3):575-580.
[2]	曹阳, 胡学功, 郭朝红, 等. 微槽群内汽泡动力学行为对接触线的影响[J]. 工程热物理学报, 2011, 32(9):1527-1530. CAO Y, HU X G, GUO C H, et al. The influence of bubble dynamics on solid-liquid-vapor triple-phase contact line in capillary microgrooves[J]. Journal of Engineering Thermophysics, 2011, 32(9):1527-1530.
[3]	SAAD I, MAALEJ S, ZAGHDOUDI M C. Combined effects of heat input power and filling fluid charge on the thermal performance of an electrohydrodynamic axially grooved flat miniature heat pipe[J]. Applied Thermal Engineering, 2018, 134:469-483.
[4]	SHEU T S, DING P P, LO I M, et al. Effect of surface characteristics on capillary flow in triangular microgrooves[J]. Experimental Thermal and Fluid Science, 2000, 22(1/2):103-110.
[5]	郭磊, 刁彦华, 赵耀华, 等. 电场强化微槽道结构毛细芯蒸发器的传热特性[J]. 化工学报, 2014, 65(S1):144-151. GUO L, DIAO Y H, ZHAO Y H, et al. Heat transfer characteristics of evaporator with rectangular microgrooves under electric field[J]. CIESC Journal, 2014, 65(S1):144-151.
[6]	STROES G R, CATTON I. A semi analytical model to predict the dryout point in inclined rectangular channels heated from below[C]//Proceedings of the 11th Heat Transfer Conference, Kyonkjui:Heat Transfer Conference, 1998:133-138.
[7]	NILSON R H, TCHIKANDA S W, GRIFFITHS S K, et al. Steady evaporating flow in rectangular microchannels[J]. International Journal of Heat and Mass Transfer, 2006, 49(9/10):1603-1618.
[8]	YU D, HU X G, GUO C H, et al. Investigation on meniscus shape and flow characteristics in open rectangular microgrooves heat sinks with micro-PIV[J]. Applied Thermal Engineering, 2013, 61(2):716-727.
[9]	胡学功, 白莉, 王照亮, 等. 竖直矩形毛细微槽群轴向干涸高度的理论分析[J]. 中国石油大学学报:自然科学版, 2007, 31(3):119-123. HU X G, BAI L, WANG Z L, et al. Theoretical analysis of axial dryout point height in vertical rectangular capillary microgrooves[J]. Journal of China University of Petroleum, 2007, 31(3):119-123.
[10]	NIE X L, HU X G, TANG D W. Modeling study on axial wetting length of meniscus in vertical rectangular microgrooves[J]. Applied Thermal Engineering, 2013, 52(2):615-622.
[11]	GHAJAR M, DARABI J. Evaporative heat transfer analysis of a micro loop heat pipe with rectangular grooves[J]. International Journal of Thermal Sciences, 2014, 79:51-59.
[12]	江乐新, 王从权. 矩形微通道内流体流动特性的数值研究[J]. 热科学与技术, 2012, 11(1):59-63. JIAGN L X, WNAG C Q. Numerical study of flowing characteristics in rectangular microchannels[J]. Journal of Thermal Science and Technology, 2012, 11(1):59-63.
[13]	王涛, 胡学功, 唐大伟, 等. 矩形毛细微槽中三角形区域接触线特性的研究[J]. 工程热物理学报, 2009, 30(11):1892-1894. WANG T, HU X G, TANG D W, et al. Study on the characteristic of contact line in a triangle-wetting region of rectangular capillary microgrooves[J]. Journal of Engineering Thermophysics, 2009, 30(11):1892-1894.
[14]	柴永志, 张伟, 李亚, 等. 非均匀润湿性微通道表面池沸腾换热特性[J]. 化工学报, 2017, 68(5):1852-1859. CHAI Y Z, ZHANG W, LI Y, et al. Pool boiling heat transfer on heterogeneous wetting microchannel surfaces[J]. CIESC Journal, 2017, 68(5):1852-1859.
[15]	YU Z, HALLINANI K, BHAGAT W, et al. Electrohydrodynamically augmented micro heat pipes[J]. Journal of Thermophysics and Heat Transfer, 2002, 16(2):180-186.
[16]	LACKOWSKI M, KRUPA A, BUTRYMOWICZ D. Dielectrophoresis flow control in microchannels[J]. Journal of Electrostatics, 2013, 71(5):921-925.
[17]	刁彦华, 汪顺, 郭磊, 等. 电场强化微槽道结构蒸发器传热特性的实验研究[J]. 北京工业大学学报, 2014, 40(11):1707-1711. DIAO Y H, WANG S, GUO L, et al. Effect of electric field on the enhanced heat transfer characteristics of an evaporator with rectangular micro-channels[J]. Journal of Beijing University of Technology, 2014, 40(11):1707-1711.
[18]	DIAO Y H, GUO L, LIU Y, et al. Electric field effect on the bubble behavior and enhanced heat-transfer characteristic of a surface with rectangular microgrooves[J]. International Journal of Heat and Mass Transfer, 2014, 78:371-379.
[19]	FANG X Z, HU X G, YU D, et al. Experimental study of the heat transfer characteristic in vertical rectangular capillary microgrooves heat sink under an electric field[C]//ASME International Conference on Nanochannels. Japan, 2013.
[20]	SUMAN B. A steady state model and maximum heat transport capacity of an electrohydrodynamically augmented micro-grooved heat pipe[J]. International Journal of Heat and Mass Transfer, 2006, 49(21/22):3957-3967.
[21]	秦志胜, 罗小平. 竖直微槽道内EHD强化饱和沸腾传热研究[J]. 低温与超导, 2010, 38(7):72-76. QIN Z S, LUO X P. EHD enhanced heat transfer in saturated boiling in vertical micro-channels[J]. Cryogenics & Superconductivity, 2010, 38(7):72-76.
[22]	CHANG F L, HUNG Y M. Dielectric liquid pumping flow in optimally operated micro heat pipes[J]. International Journal of Heat and Mass Transfer, 2017, 108:257-270.
[23]	STRATTON J A. Electromagnetic Theory[M]. Beijing:Science Press, 1992.
[24]	李超, 吴慧英, 黄荣宗. 电场作用下液滴分裂动力学行为的格子Boltzmann模拟[J]. 化工学报, 2014, 65(8):2882-2888. LI C, WU H Y, HUANG R Z. Lattice Boltzmann simulation of droplet breakup dynamic behavior under electric field[J]. CIESC Journal, 2014, 65(8):2882-2888.
[25]	CATTON I, STROES G R. A semi-analytical model to predict the capillary limit of heated inclined triangular capillary grooves[J]. J. Heat Transfer, 2001, 124(1):162-168.
[26]	SCHNEIDER G, DEVOS R. Non-dimensional analysis for the heat transport capability of axially grooved heat pipes including liquid/vaporinteraction[C]//18th Aerospace Sciences Meeting. Pasadena, CA, USA:AIAA, 1980, https://doi.org/10.2514/6.1980-214.
[27]	AYYASWAMY P S, CATTON I, EDWARDS D K. Capillary flow in triangular grooves[J]. J. Appl. Mech., 1974, 41(2):332-336.
[28]	STROES G. An experimental and analytical investigation of the wetted length supported in inclined capillary grooves heated from below[D]. Los Angeles, CA:UCLA, 1997.
[29]	钟艳, 罗小平. 微细通道EHD两相流传热研究[J]. 石油机械, 2011, 39(2):7-11+91. ZHONG Y, LUO X P. Research on the heat transfer of the EHD two-phase flow in the micro-channel[J]. China Petroleum Machinery, 2011, 39(2):7-11+91.
[30]	黄岗, 罗小平, 孙胜, 等. EHD强化微槽道两相流传热动力学研究[J]. 低温与超导, 2013, 41(9):59-64. HUANG G, LUO X P, SUN S, et al. Dynamic research of EHD enhancement two-phase flow heat transfer in micro channel[J]. Cryogenics & Superconductivity, 2013, 41(9):59-64.