Effect of heat source temperature on flow heat transfer in asymmetric nanochannels

doi:10.16085/j.issn.1000-6613.2024-0184

Abstract

Abstract:

In response to the current demand for miniaturized and high-performance heat dissipation in electronic devices, the study of fluid flow heat transfer within nanochannels has garnered significant attention. In this paper, the molecular dynamics simulation method was used to investigate the heat transfer characteristics of water molecules flowing through asymmetric channels under varying heat source temperatures. The results indicated that the fluid flow and heat transfer process were affected by the increase of the groove structure in the bottom part and the change of the heat source temperature. The increase of groove structure enhanced the gathering ability of water molecules at the structure, while higher heat source temperature dispersed the high-density region formed. However, increasing the groove structure weakened the overall flow velocity in the channel, reduced the velocity slip at the bottom wall surface, and increased the flow resistance coefficient. Conversely, increasing the heat source temperature had the opposite effect, improving the process of the water molecule flow. Under the same heat source temperature, the temperature of water molecules near the bottom rough wall surface was higher than that near the top wall surface. Increasing the groove structure will increase the heat transfer area between the solid-liquid, reduce the temperature jump length of the solid-liquid interface, and increase the Nusselt number. However, increasing the temperature of the heat source will enhance the temperature jump length of the interface, weaken the heat transfer between the solid-liquid, widen the temperature difference between the fluid and the heating wall, and decrease the Nusselt number.

Key words: heat source temperature, flow, heat transfer, molecular simulation, nanostructure, asymmetric

摘要：

为满足当前小型化、高性能电子器件的散热需求，流体在纳米通道内的流动传热成为研究焦点。本文采用分子动力学方法，模拟了不同热源温度下，水分子在非对称通道内的流动换热性能。结果表明，下部增设凹槽结构及改变热源温度对流体的流动及传热过程均会有所影响。凹槽结构增多会增强水分子在结构处的聚集能力，而热源温度升高会分散已形成的高质量密度区域；增设凹槽结构会削弱流体在通道内的整体流动速度，减小下壁面处的滑移速度，增大流动阻力系数，而升高热源温度与之作用相反，会改善水分子的流动过程；同一热源温度下，下部粗糙壁面附近的水分子温度要高于上壁面附近处，增设凹槽结构会增大固液之间的传热面积，减小固-液界面的温度跳跃长度，增大努塞尔特数，而升高热源温度会增大界面处的温度跳跃长度，削弱固液间的换热，拉大流体与加热壁面间的温差，降低努塞尔特数。

关键词: 热源温度, 流动, 传热, 分子模拟, 纳米结构, 非对称

CLC Number:

TK124

SU Yao, CHEN Zhanxiu, YANG Li, XING Hewei, HU Hecang, LI Yuanhua. Effect of heat source temperature on flow heat transfer in asymmetric nanochannels[J]. Chemical Industry and Engineering Progress, 2024, 43(S1): 144-153.

苏瑶, 陈占秀, 杨历, 邢赫威, 呼和仓, 李源华. 热源温度对非对称纳米通道流动换热的影响[J]. 化工进展, 2024, 43(S1): 144-153.

Figures/Tables 13

References 26

1	TANG Heng, TANG Yong, WAN Zhenping, et al. Review of applications and developments of ultra-thin micro heat pipes for electronic cooling[J]. Applied Energy, 2018, 223: 383-400.
2	JOSEPH Pierre, TABELING Patrick. Direct measurement of the apparent slip length[J]. Physical Review E, Statistical, Nonlinear, and Soft Matter Physics, 2005, 71(3): 035303.
3	TOGHRAIE Davood, HEKMATIFAR Maboud, SALEHIPOUR Yasaman, et al. Molecular dynamics simulation of Couette and Poiseuille water-copper nanofluid flows in rough and smooth nanochannels with different roughness configurations[J]. Chemical Physics, 2019, 527: 110505.
4	BITSANIS Ioannis, MAGDA Jules J, TIRRELL Matthew, et al. Molecular dynamics of flow in micropores[J]. The Journal of Chemical Physics, 1987, 87(3): 1733-1750.
5	GHOLAMREZA Ahmadi, Jahangiri ALI, MOHAMMAD Ameri. The effects of transferred heat and wall material on thermal behavior of a nano-grooved micro-heat pipe, molecular dynamics simulation[J]. Engineering Analysis with Boundary Elements, 2024, 160: 1-13.
6	PIT R, HERVET H, LEGER L. Direct experimental evidence of slip in hexadecane: Solid interfaces[J]. Physical Review Letters, 2000, 85(5): 980-983.
7	CAO Bingyang, CHEN Min, GUO Zengyuan. Effect of surface roughness on gas flow in microchannels by molecular dynamics simulation[J]. International Journal of Engineering Science, 2006, 44(13/14): 927-937.
8	JING Dalei, BHUSHAN Bharat. The coupling of surface charge and boundary slip at the solid-liquid interface and their combined effect on fluid drag: A review[J]. Journal of Colloid and Interface Science, 2015, 454: 152-179.
9	JUNG Jung-Yeul, KWAK Ho-Young. Effect of surface condition on boiling heat transfer from silicon chip with submicron-scale roughness[J]. International Journal of Heat and Mass Transfer, 2006, 49(23/24): 4543-4551.
10	SONG Zhao, SHANG Xueshuo. Investigation of surface structure-wettability coupling on heat transfer and flow characteristics in nanochannels[J]. Applied Thermal Engineering, 2023, 218: 119362.
11	THOMPSON Peter A, ROBBINS Mark O. Shear flow near solids: Epitaxial order and flow boundary conditions[J]. Physical Review A, 1990, 41(12): 6830-6837.
12	SONG Zhao, CUI Zheng, CAO Qun, LIU Yu, LI Junhui. Molecular dynamics study of convective heat transfer in ordered rough nanochannels[J]. Journal of Molecular Liquids, 2021, 337: 116052.
13	徐超, 何雅玲, 王勇. 纳米通道滑移流动的分子动力学模拟研究[J]. 工程热物理学报, 2005, 26(6): 912-914.
	XU Chao, HE Yaling, WANG Yong. Molecular dynamics studies of velocity slip phenomena in a nanochannel[J]. Journal of Engineering Thermophysics, 2005, 26(6): 912-914.
14	刘洁, 刘万强, 孙林萍, 等. 温度对有机物传热影响的分子动力学模拟及微观机理研究[J]. 原子与分子物理学报, 2023, 40(3): 69-78.
	LIU Jie, LIU Wanqiang, SUN Linping, et al. Molecular dynamics simulation and microscopic mechanism study on the effect of temperature on heat conduction of liquid organic[J]. Journal of Atomic and Molecular Physics, 2023, 40(3): 69-78.
15	陈洁敏. 微纳尺度气体流动速度滑移的分子动力学研究[D]. 杭州: 中国计量大学, 2018.
	CHEN Jiemin. Molecular dynamics study on the velocity slip of micro/nano scale gas flow[D]. Hangzhou: China University of Metrology, 2018.
16	梅涛, 陈占秀, 杨历, 等. 非对称纳米通道内界面热阻的分子动力学研究[J]. 物理学报, 2020, 69(22): 326-338.
	MEI Tao, CHEN Zhanxiu, YANG Li, et al. Molecular dynamics study of interface thermal resistance in asymmetric nanochannel[J]. Acta Physica Sinica, 2020, 69(22): 326-338.
17	高志强. 离子液体及其纳米流体热物性的分子动力学模拟[D]. 吉林: 东北电力大学, 2023.
	GAO Zhiqiang. Molecular dynamics simulation on thermophysical properties of ionic liquid and ionic liquid-based nanofluids[D]. Jilin: Northeast Dianli University, 2023.
18	周健, 陆小华, 王延儒, 等. Lennard-Jones流体固液相变的分子动力学模拟[J]. 南京化工大学学报, 1997, 19(2): 20-25.
	ZHOU Jian, LU Xiaohua, WANG Yanru, et al. Molecular dynamics simulation for the solid liquid transition of Lennard-Jones fluid[J]. Journal of Nanjing University of Chemical Technology (Natural Science Edition), 1997, 19(2): 20-25.
19	白璞. 粗糙度和润湿性影响沸腾的分子动力学研究[D]. 北京: 华北电力大学, 2022.
	BAI Pu. Molecular dynamics study of boiling affected by roughness and wettability[D]. Beijing: North China Electric Power University, 2022.
20	BERENDSEN H J C, GRIGERA J R, STRAATSMA T P. The missing term in effective pair potentials[J]. The Journal of Physical Chemistry, 1987, 91(24): 6269-6271.
21	WU Nini, ZENG Liangcai, FU Ting, et al. Mechanism of heat transfer enhancement by nanochannels copper plate interface wettability: A molecular dynamics study[J]. International Journal of Thermal Sciences, 2021, 159: 106589.
22	曹炳阳, 陈民, 过增元. 粗糙微通道内气体流动的分子动力学研究[J]. 工程热物理学报, 2004, 25(S1): 131-134.
	CAO Bingyang, CHEN Min, GUO Zengyuan. Molecular dynamics study on gas flow in rough microchannels[J]. Journal of Engineering Thermophysics, 2004, 25(S1): 131-134.
23	张龙艳. 微尺度下流体的流动换热及核化沸腾的分子动力学研究[D]. 北京: 华北电力大学, 2019.
	ZHANG Longyan. Molecular dynamics simulation of fluid flow and heat transfer and nucleate boiling in microscale[D]. Beijing: North China Electric Power University, 2019.
24	孙杰, 何雅玲, 李印实, 等. 膜状冷凝初期过程的分子动力学模拟研究[J]. 西安交通大学学报, 2007, 41(9): 1087-1091.
	SUN Jie, HE Yaling, LI Yinshi, et al. Molecular dynamics study on early stage of filmwise condensation[J]. Journal of Xi'an Jiaotong University, 2007, 41(9): 1087-1091.
25	刘峰瑞, 陈占秀, 李源华. 混合润湿性柱状纳米结构对铜板上纳米氩膜沸腾传热的影响[J]. 原子与分子物理学报, 2024, 41(3): 66-76.
	LIU Fengrui, CHEN Zhanxiu, LI Yuanhua. Effects of columnar nanostructures with mixed wettability on explosive boiling heat transfer of nanoscale argon film over copper plate[J]. Journal of Atomic and Molecular Physics, 2024, 41(3): 66-76.
26	YAO Shuting, WANG Jiansheng, JIN Shufeng, et al. Atomistic insights into the microscope mechanism of solid-liquid interaction influencing convective heat transfer of nanochannel[J]. Journal of Molecular Liquids, 2023, 371: 121105.

案例	凹槽间距 d/Å	凹槽长度 l/Å	凹槽宽度 w/Å	凹槽高度 h/Å	凹槽数量n
1	21.7	18.1	18.1	10.86	2
2	16.25	18.1	18.1	10.86	3
3	13	18.1	18.1	10.86	4
4	10.8	18.1	18.1	10.86	5

案例	凹槽间距 d/Å	凹槽长度 l/Å	凹槽宽度 w/Å	凹槽高度 h/Å	凹槽数量n
1	21.7	18.1	18.1	10.86	2
2	16.25	18.1	18.1	10.86	3
3	13	18.1	18.1	10.86	4
4	10.8	18.1	18.1	10.86	5

原子类型	能量参数ɛ/kcal∙mol^-1	特征长度σ/Å
O-O	0.1554	3.166
H-O/Cu	0	0
Cu-Cu	9.44	2.34
O-Cu	0.26	2.753

原子类型	能量参数ɛ/kcal∙mol^-1	特征长度σ/Å
O-O	0.1554	3.166
H-O/Cu	0	0
Cu-Cu	9.44	2.34
O-Cu	0.26	2.753

案例	平均速度/m·s^-1
案例	T=300K	T=320K	T=340K	T=360K
1	15.71	22.97(↑46.2%)	27.76(↑76.7%)	34.01(↑116.5%)
2	15.52	19.33(↑24.5%)	25.14(↑62.0%)	30.91(↑99.2%)
3	12.59	15.88(↑26.1%)	19.51(↑55.0%)	25.78(↑104.8%)
4	10.51	13.96(↑32.8%)	17.04(↑62.1%)	22.78(↑116.7%)