气流对含气泡油滴撞壁铺展流动过程的影响

doi:10.3901/JME.2020.17.216

机械工程学报 ›› 2020, Vol. 56 ›› Issue (17): 216-224.doi: 10.3901/JME.2020.17.216

扫码分享

气流对含气泡油滴撞壁铺展流动过程的影响

童宝宏¹, 苏家磊¹, 张国涛¹, 郑楠¹, 郭丹², 王伟³, 刘焜³

1. 安徽工业大学机械工程学院马鞍山 243032;
2. 清华大学摩擦学国家重点实验室北京 100084;
3. 合肥工业大学机械工程学院合肥 230009

收稿日期:2019-09-19 修回日期:2020-04-16 出版日期:2020-09-05 发布日期:2020-10-19
通讯作者: 童宝宏(通信作者),男,1978年出生,博士,教授,硕士研究生导师。主要研究方向为流体流动与润滑力学、流-固界面力学行为与调控等。E-mail:bhtong@ahut.edu.cn
作者简介:苏家磊,男,1994年出生,硕士研究生。主要研究方向为流体流动与润滑力学。E-mail:su18955519668@163.com
基金资助:
国家自然科学基金（51975005，51975174，51875152，51875154）、清华大学摩擦学国家重点实开放基金（SKLTKF17B01）和安徽省自然科学基金（2008085ME148，1908085QE195）资助项目。

Effect of Airflow on the Spreading Process of Hollow Oil Droplets after Wall Impacting

TONG Baohong¹, SU Jialei¹, ZHANG Guotao¹, ZHENG Nan¹, GUO Dan², WANG Wei³, LIU Kun³

1. School of Mechanical Engineering, Anhui University of Technology, Maanshan 243032;
2. State Key Laboratory of Tribology, Tsinghua University, Beijing 100084;
3. School of Mechanical Engineering, Hefei University of Technology, Hefei 230009

Received:2019-09-19 Revised:2020-04-16 Online:2020-09-05 Published:2020-10-19

摘要/Abstract

摘要： 油-气润滑系统工作过程中，有效的润滑油膜是确保摩擦副润滑效果的关键，其形成质量与输送气流作用下含气泡油滴撞壁后的铺展流动过程密切相关。为探索该铺展流动过程，基于VOF（Volume of fluid）方法对输送气流作用下含气泡油滴的撞壁过程进行数值模拟研究。观察了输送气流作用下含气泡油滴撞壁后的铺展流动过程，探讨了气流入射角及碰撞-气流速度比对含气泡油滴铺展特性的影响，分析了铺展过程中的气泡破裂及中心射流机制。发现当气流方向与含气泡油滴碰撞方向（竖直方向）存在差异时，含气泡油滴撞壁后在x方向的铺展呈非对称性。随着气流入射角的减小，非对称铺展现象越明显。碰撞-气流速度比增大时，非对称铺展现象减弱。碰撞速度较低（碰撞-气流速度比小于4）时含气泡油滴撞壁后，上侧油膜厚度不断减小直至达到极限值，最终在气流拖曳力、黏性剪切力及表面张力的共同作用下发生破裂。碰撞速度较高（碰撞-气流速度比等于4）时含气泡油滴撞壁后，其内部产生的速度涡旋致使部分铺展油液向气泡底部汇聚，中心射流得以形成。中心射流逐步发展直至穿透上侧油膜，气泡发生破裂。之后，气泡两侧油膜发生破碎并形成膜油滴，壁面油膜逐渐收缩成油膜层。

关键词: 气流, 含气泡油滴, 碰撞, 非对称铺展, VOF

Abstract: In the oil-air lubrication system, the effective lubrication film is the key to ensure the lubrication effect, and its formation quality is closely related to the spreading flow process of the hollow oil droplets impacting the wall in the conveying airflow. To explore the spreading flow process, the VOF method is adapted to numerically simulate the wall impact process of the hollow oil droplet in the conveying airflow. The spreading process is observed, the effects of incident angle and collision-airflow velocity ratio on the spreading characteristics are discussed, and the bubble breakdown and central jet mechanism in the spreading process are analyzed. It is found that when the airflow direction is different from the collision direction (vertical direction) of the hollow oil droplet, the spread of the hollow oil droplet in the x direction is asymmetric. With the decrease of the incidence angle, the asymmetric spreading becomes more obvious. When the velocity ratio of collision-airflow increases, the phenomenon decreases. At lower collision velocity (collision-airflow velocity ratio less than 4), the oil film thickness upper side of the bubble decreases to the limit in the spreading process, and finally the bubble ruptures under the combined action of airflow drag force, viscous shear force and surface tension. At higher collision velocity (collision-airflow velocity ratio equal to 4), the velocity vortices generated inside the droplets after wall impact cause part of the spreading oil to converge to the bottom of the bubble, and the central jet is formed. With the further development of the central jet, it penetrates the oil film on the upper side of the bubble and the bubble bursts. After that, the oil film on both sides of the bubble breaks up and forms film droplets, and the oil film on the wall gradually shrinks to form oil film layer.

Key words: airflow, hollow oil droplet, impact, asymmetric, VOF

中图分类号:

O359

童宝宏, 苏家磊, 张国涛, 郑楠, 郭丹, 王伟, 刘焜. 气流对含气泡油滴撞壁铺展流动过程的影响[J]. 机械工程学报, 2020, 56(17): 216-224.

TONG Baohong, SU Jialei, ZHANG Guotao, ZHENG Nan, GUO Dan, WANG Wei, LIU Kun. Effect of Airflow on the Spreading Process of Hollow Oil Droplets after Wall Impacting[J]. Journal of Mechanical Engineering, 2020, 56(17): 216-224.

参考文献

[1] YILBAS B S,HASSAN G,AL-SHAl-Sharafi A,et al. Water droplet dynamics on a hydrophobic surface in relation to the self-cleaning of environmental dust[J]. Scientific Reports,2018,8(1):2984.
[2] ZHANG G,QUETZERI-SANTIAGO M A,STONE C A,et al. Droplet impact dynamics on textiles[J]. Soft Matter, 2018, 14:8182-8190.
[3] LI H Z,FANG W,LI Y N,et al. Spontaneous droplets gyrating via asymmetric self-splitting on heterogeneous surfaces[J]. Nature Communications,2019,10:950.
[4] BOELENS A M P,DE P J J. Simulations of splashing high and low viscosity droplets[J]. Physics of Fluids,2018,30(7):072106.
[5] BAEK S,MOON H S,KIM W,et al. Effect of liquid droplet surface tension on impact dynamics over hierar-chical nanostructure surfaces[J]. Nanoscale,2018,10:17842-17851.
[6] XIE J,XU J L,SHANG W,et al. Mode selection between sliding and rolling for droplet on inclined surface:Effect of surface wettability[J]. International Journal of Heat and Mass Transfer,2018,122:45-58.
[7] TANG C L,QIN M X,WENG X Y,et al. Dynamics of droplet impact on solid surface with different roughness[J]. International Journal of Multiphase Flow,2017,96:56-69.
[8] DIAZ A J,ORTEGA A. Gas-assisted droplet impact on a solid surface[J]. Journal of Fluids Engineering,2016,138(8):081104.
[9] FAN J,WILSON M C T,KAPUR N. Displacement of liquid droplets on a surface by a shearing air flow[J]. Journal of Colloid and Interface Science,2011,356(1):286-292.
[10] GULYAEV I P,SOLONENKO O P,GULYAEV P Y,et al. Hydrodynamic features of the impact of a hollow spherical drop on a flat surface[J]. Technical Physics Letters,2009,35(10):885-888.
[11] GULYAEV I P,SOLONENKO O P. Hollow droplets impacting onto a solid surface[J]. Experiments in Fluids,2013,54(1):1432-1443.
[12] 郑志伟,李大树,仇性启,等. 中空液滴碰撞水平壁面数值分析[J]. 物理学报,2017,66(1):235-244. ZHENG Zhiwei,LI Dashu,QIU Xingqi,et al. Numerical analysis of hollow droplet impact on a flat surface[J]. Acta Physica Sinica,2017,66(1):235-244.
[13] 周剑宏,童宝宏,王伟,等. 含气泡油滴撞击油膜壁面时气泡的变形与破裂. 力学学报,2018,50(2):427-437. ZHOU Jianghong,TONG Baohong,WANG Wei,et al. Deformation and rupture of bubble when the hollow droplet impacts on the oil film[J]. Chinese Journal of Theor-etical and Applied Mechanics,2018,50(2):427-437.
[14] ZHOU J H,TONG B H,WANG W,et al. Numerical simulation of bubble changes in an oil film impacted by oil droplets via a coupled level set and volume-of-fraction method[J]. Fluid Dynamics Research,2019,51:025502.
[15] 方龙,陈国定,刘登. 喷射油滴沉积油膜的流动铺展特性研究[J]. 机械工程学报,2016,52(23):160-167. FANG Long,CHEN Guoding,LIU Deng. Study on flow characteristics of deposited oil film formed by sprayed oil droplets[J],Journal of Mechanical Engine-ering,2016,52(23):160-167.
[16] LV M,NING Z,SUN C H. Numerical simulation of cavitation bubble collapse within a droplet[J]. Computers and Fluids,2017,152:157-163.
[17] BOELENS A M P,DE P J J. Simulations of splashing high and low viscosity droplets[J]. Physics of Fluids,2018,30(7):072106.
[18] GUO Y L,SHEN S Q,QUAN S L. Numerical simulation of dynamics of droplet impact on heated flat solid surface[J]. International Journal of Low-Carbon Technologies,2013,8(2):134-139.
[19] DENG L D,WANG H,ZHUN X,et al. Numerical study of water droplets impacting on cylindrical heat transfer pipes[J]. Engineering Applications of Compu-tational Fluid Mechanics,2018,12(1):598-610.
[20] KUMAR A,GU S,KAMNIS S. Simulation of impact of a hollow droplet on a flat surface[J]. Applied Physics A,2012,109(1):101-109.

气流对含气泡油滴撞壁铺展流动过程的影响

Effect of Airflow on the Spreading Process of Hollow Oil Droplets after Wall Impacting

PDF

可视化

摘要/Abstract

引用本文

使用本文

参考文献

相关文章 15

编辑推荐

Metrics

本文评价

[1]	畅博彦, 韩芳孝, 周杨, 金国光. 面向精梳任务的高速变胞机构冲击动力学研究[J]. 机械工程学报, 2024, 60(7): 54-65.
[2]	杨炜烽, 刘检华, 吕乃静, 马江涛. 基于位置动力学的线缆运动过程仿真方法[J]. 机械工程学报, 2024, 60(6): 21-31,57.
[3]	张志勇, 王宇翔, 黄彩霞, 吴悠, 杜荣华. 融合灰色预测和卡尔曼滤波的车辆侧向碰撞预警[J]. 机械工程学报, 2024, 60(20): 240-250.
[4]	王方, 尹嘉杰, 胡林, 王明亮, 石亮亮, 邹铁方, 刘鑫, ZHOU Zhou. 真实汽车事故中人体头部运动学边界对损伤机制影响研究[J]. 机械工程学报, 2024, 60(12): 321-334.
[5]	黄涛, 王家畴, 李昕欣. (111)硅片的高性能热堆式气体流量传感器及其封装技术研究[J]. 机械工程学报, 2023, 59(2): 30-38.
[6]	张建华, 任宝珍, 赵岩, 徐永强, 刘璇. 基于二分试探的平面冗余机械臂碰撞检测与避障[J]. 机械工程学报, 2023, 59(1): 113-122.
[7]	周怡, 齐乐华, 罗俊, 苏林. 微域保护气对金属微滴喷射过程影响机制研究[J]. 机械工程学报, 2023, 59(1): 219-230.
[8]	卞贵学, 王安东, 张勇, 王玺, 樊伟杰, 陈跃良. 海洋气流气溶胶传输与沉降模型研究[J]. 机械工程学报, 2022, 58(8): 285-292.
[9]	李锦龙, 刘传耙, 孙涛, 张弢, 连宾宾, 宋轶民. 面向并联骨折手术机器人的复位轨迹自动式规划方法[J]. 机械工程学报, 2022, 58(5): 26-33.
[10]	李红刚, 张超, 曹俊超, 周典, 张美合. 锂离子电池碰撞安全仿真方法的研究进展与展望[J]. 机械工程学报, 2022, 58(24): 121-144.
[11]	高海波, 王英超, 于海涛, 刘振, 丁亮, 宋宝玉, 邓宗全. 支腿式着陆装置运载器缩比模型相似性分析[J]. 机械工程学报, 2022, 58(22): 360-368.
[12]	吕乃静, 刘检华. 柔性线缆的机器人自动敷设关键技术与发展趋势[J]. 机械工程学报, 2022, 58(17): 75-95.
[13]	刘茜, 程靖, 梁建勋. 混合碰撞建模方法及其试验验证[J]. 机械工程学报, 2022, 58(1): 116-123.
[14]	王志远, 邢志国, 王海斗, 单徳彬. 液滴在固体织构化表面上的润湿行为研究现状[J]. 机械工程学报, 2022, 58(1): 124-144.
[15]	邹铁方, 刘期, 刘朱紫, 胡林. 真实事故中通过制动控制降低人地碰撞损伤的潜在效益及时空约束[J]. 机械工程学报, 2021, 57(22): 266-276.