The seawater surface tension coefficient representation with different salinities
-
摘要: 为研究不同盐度下海水表面张力系数的表征，并精简其表面张力系数的测定手段，根据气泡在海水中的受力情况，建立了海水中的气泡脱离体积及瞬时稳态上浮速度模型。通过搭建气体水下排放试验台，使用常压空气和6种不同盐度的海水分别作为实验的气相和液相，将气泡划分为低雷诺数缓慢上浮及高雷诺数快速上浮2种运动状态，并分别进行实验。用高速摄影技术对气泡运动进行实验观测，通过MATLAB编程对拍摄的图像进行分析处理，测定气泡脱离体积及瞬时稳态上浮速度。将实验数据代入到所建立的模型中，获得不同盐度下海水表面张力系数表征函数。结果表示，当气泡在非射流情况下生成及上浮时，气泡处于小半径慢速运动状态，属于低雷诺数运动过程，海水盐度与表面张力系数拟合效果理想，模型计算值与实验数据符合良好，偏离程度不到2%。Abstract: To study the seawater surface tension coefficient representation with different salinities and to simplify the test methods, a practical model for the bubble departure volume and the departure instantaneous velocity is built by analyzing the forces experienced by the bubble in the seawater. The underwater gas emission experimental platform is constructed. It uses the normal pressure air and six kinds of salinity seawater as the experiment's gaseous phase and liquid phase. And the bubble motions are categorized as slow motion with low Reynolds number and fast motion with high Reynolds number. Experiments with both bubble motions are conducted. The high-speed photography technology is used to record the bubble motion, and the filmed pictures are analyzed by the MATLAB program, so as to obtain the bubble departure volume and the departure instantaneous velocity. Substituting the experimental data into models, the seawater surface tension coefficient representation with different salinities can be acquired. The result shows that, under the non jet generation and flotation condition, the bubble is of small radius and has slow movement with low Reynolds number. The simulation results are in consistency with the measurement with high credibility and low divergence. The error is less than 2%.
-
Key words:
- bubble formation /
- seawater salinity /
- bubble volume /
- bubble rising velocity
-
表 1 不同盐度海水物性参数
Table 1. Seawater physical parameters with different salinities
Seawater salinity/‰ Density/(kg·m-3) Viscosity coefficient /(10－3Pa·s) 15 1010.9 17.628 20 1014.8 17.649 25 1018.6 17.662 30 1022.4 17.673 35 1026.2 17.682 40 1030 17.688 
下载: 导出CSV
表 2 气泡在不同盐度海水中的脱离体积
Table 2. The variance of bubble departure volumewith differentseawater salinities
Salinity/‰ Volume/mm3 Salinity/‰ Volume/mm3 15 297.522 20 290.102 25 284.127 30 281.368 35 279.851 40 273.165
下载: 导出CSV
表 3 气泡在不同盐度海水中瞬时稳态上浮速度
Table 3. The bubble instantaneous velocity change with seawater salinity
气泡等效半径R＜7mm 气泡等效半径R＞7mm Salinity/‰ Velocity(cm/s) Salinity/‰ Velocity (cm/s) Velocity(cm/s) Salinity/‰ Velocity(cm/s) 15 24.01 20 26.19 32.74 20 31.96 25 26.76 30 27.19 31.30 30 31.19 35 28.07 40 28.06 31.02 40 30.71
下载: 导出CSV
表 4 不同盐度、温度条件下海水表面张力系数
Table 4. The surface tension coefficient with various salinities and at different temperatures
Salinity/‰ Surface tension coefficient at 20.3℃/(mN·m-1) Surface tension coefficient at 25.1℃/(mN·m-1) 15 73.15284 72.40355 20 73.23027 72.5014 25 73.2689 72.5721 30 73.38591 72.63967 35 73.45324 72.71793 40 73.52156 72.7817
下载: 导出CSV
表 5 不同盐度、温度条件下海水表面张力系数
Table 5. The surface tension coefficient with various salinities and at different temperatures
气泡等效半径R＜7mm 气泡等效半径R＞7mm Salinity/‰ Surface tension coefficient at 20.3℃/(mN·m-1) Surface tension coefficient at 25.1℃/(mN·m-1) Surface tension coefficient at 20.3℃/(mN·m-1) Surface tension coefficient at 25.1℃/(mN·m-1) 15 73.16371 72.41422 73.26371 72.51422 20 73.2281 72.5014 73.1281 72.5014 25 73.2689 72.5691 73.2689 72.5991 30 73.38917 72.65131 73.48917 72.67131 35 73.43267 72.72152 73.53267 72.82152 40 73.52156 72.7791 73.52156 72.8791
下载: 导出CSV
-
[1] 朱英昊, 康娟, 桑涛, 等.基于光纤干涉法的液体表面张力系数测量及温度影响研究[J].光电子·激光, 2015, (1):130-134. http://www.cnki.com.cn/Article/CJFDTOTAL-GDZJ201501022.htmZhu Y H, Kang J, Sang T, et al. Liquid surface tension coefficient measurement and temperature impact based on optical interference method[J]. Journal of Optoelectronics Laser, 2015, (1):130-134. http://www.cnki.com.cn/Article/CJFDTOTAL-GDZJ201501022.htm [2] Zhang X B, Xiang S J, Cao Q, et al. Effects of surface tension on bubble growth in an extensive uniformly superheated liquid[J]. Chinese Science Bulletin, 2011, 30:3191-3198. doi: 10.1007%2Fs11434-011-4699-1.pdf?origin=publication_detail [3] 赵贯甲, 毕胜山, 吴江涛.表面光散射法液体黏度和表面张力实验系统研制[J].工程热物理学报, 2015, (1):36-40. http://www.cnki.com.cn/Article/CJFDTOTAL-GCRB201501008.htmZhao J S, Bi S S, Wu J T. Liquid viscosity and surface tension measurement under saturated condition with surface laser light scattering method[J]. Journal of Engineering Thermophysics, 2015, (1):36-40. http://www.cnki.com.cn/Article/CJFDTOTAL-GCRB201501008.htm [4] Mohammed I U, Deeni Y, Hapca S M, et al. Predicting the minimum liquid surface tension activity of pseudomonads expressing biosurfactants[J]. Letters in Applied Microbiology, 2015, 60(1):37-43. doi: 10.1111/lam.2014.60.issue-1 [5] 张鹏.海水表面张力的研究[J].山西师范大学学报(自然科学版), 2011, (4):44-45. http://www.cnki.com.cn/Article/CJFDTOTAL-HYFZ199403011.htmZhang P. Study on the surface tension of sea water[J]. Journal of Shanxi Normal University Natural Science Edition, 2011, (4):44-45. http://www.cnki.com.cn/Article/CJFDTOTAL-HYFZ199403011.htm [6] 成娟, 李玲, 刘科.液体表面张力系数与浓度的关系实验研究[J].中国测试, 2014, (3):32-34. doi: 10.11857/j.issn.1674-5124.2014.03.009Cheng J, Li L, Liu K. Study on the relationship between liquid surface tension and concentration[J]. China Measurement & Test, 2014, (3):32-34. doi: 10.11857/j.issn.1674-5124.2014.03.009 [7] Trybula M E, Gancarz T, Gasior W. Density, surface tension and viscosity of liquid binary Al-Zn and ternary Al-Li-Zn alloys[J]. Fluid Phase Equilibria, 2016, 421:39-48. http://linkinghub.elsevier.com/retrieve/pii/S0378381216301418 [8] Zhang X B, Xiang S J, Cao X L, et al. Effects of surface tension on bubble growth in an extensive uniformly superheated liquid[J]. Chinese Science Bulletin, 2011, 30:3191-3198. doi: 10.1007/s11434-011-4699-1?view=classic [9] 田恒斗, 金良安, 王涌, 等.考虑单气泡运动特性的舰船尾流气泡分布研究[J].兵工学报, 2011, (9):1126-1130. http://www.cnki.com.cn/Article/CJFDTOTAL-BIGO201109015.htmTian H D, Jin L A, Wang Y, et al. Study on wake bubble distribution based on single bubble motion characteristics[J]. Acta Armamentarii, 2011, (9):1126-1130. http://www.cnki.com.cn/Article/CJFDTOTAL-BIGO201109015.htm [10] 薛婷, 孟欣东, 张涛.气液两相流中气泡形态及运动特征参数提取[J].光电子·激光, 2010, (8):1218-1221. http://www.cnki.com.cn/Article/CJFDTOTAL-GDZJ201008028.htmXue T, Meng X D, Zhang T. Extraction of bubble shape and motion feature parameters in the gas-liquid two-phase flow[J]. Journal of Optoelectronics Laser, 2010, (8):1218-1221. http://www.cnki.com.cn/Article/CJFDTOTAL-GDZJ201008028.htm [11] 代晓巍, 金良安, 迟卫, 等.基于双向图像的水中上升气泡溶解速率分析技术[J].化工学报, 2011, (2):315-320. http://www.cnki.com.cn/Article/CJFDTOTAL-HGSZ201102005.htmDai X W, Jin L A, Chi W, et al. Analysis technique to dissolution rate of rising bubble in water based on two-direction images[J]. CIESC Journal, 2011, (2):315-320. http://www.cnki.com.cn/Article/CJFDTOTAL-HGSZ201102005.htm [12] Chen B B, Zou D H. Altered seawater salinity levels affected growth and photosynthesis of Ulva fasciata(Ulvales, Chlorophyta)germlings[J]. Acta Oceanologica Sinica, 2015, (8):108-113. doi: 10.1007/s13131-015-0654-3 [13] 陈世哲, 刘世萱, 范秀涛, 等.基于棱镜模型多次折射法的海水盐度检测系统[J].光学学报, 2011, (7):22-26. http://www.cnki.com.cn/Article/CJFDTOTAL-GXXB201107006.htmChen S Z, Liu S X, Fan X T, et al. Seawater salinity measurement system based on prism model multi-refraction[J]. Acta Optica Sinica, 2011, (7):22-26. http://www.cnki.com.cn/Article/CJFDTOTAL-GXXB201107006.htm [14] 田恒斗, 金良安, 迟卫, 等. Basset力对液体中易溶性气泡运动的影响[J].力学学报, 2011, (4):680-687. doi: 10.6052/0459-1879-2011-4-lxxb2010-069Tian H D, Jin L A, Chi W, et al. Impact of basset force on the movement of soluble bubble in fluid[J]. Chinese Journal of Theoretical and Applied Mechanics, 2011, (4):680-687. doi: 10.6052/0459-1879-2011-4-lxxb2010-069 [15] 赵勇, 胡开博, 陈世哲, 等.海水盐度检测技术的最新进展[J].光电工程, 2008, (11):38-44. doi: 10.3969/j.issn.1003-501X.2008.11.009Zhao Y, Hu K B, Chen S Z, et al. Recent development of the seawater salinity measurement technology[J]. Opto-Electronic Engineering, 2008, (11):38-44. doi: 10.3969/j.issn.1003-501X.2008.11.009 [16] 程文, 周孝德, 郭瑾珑, 等.水中气泡上升速度的实验研究[J].西安理工大学学报, 2000, 16(1):57-60. http://www.cnki.com.cn/Article/CJFDTOTAL-XALD200001012.htmChen W, Zhou X D, Guo J L, et al. Experimental study of the velocity of bubble rising in water[J]. Journal of Xi'an University of Technology, 2000, 16(1):57-60. http://www.cnki.com.cn/Article/CJFDTOTAL-XALD200001012.htm -
点击查看大图
图(2) / 表(5)
计量
- 文章访问数: 182
- HTML全文浏览量: 145
- PDF下载量: 6
- 被引次数: 0
