摘要
液滴撞击固体壁面现象常见于动力机械、喷雾冷却和薄膜材料沉积制备等工业生产中。将石墨烯和碳纳米管作为分散颗粒,应用超声波分散技术制备均匀性与稳定性良好的树脂基纳米流体。利用高速摄像技术,研究纳米流体液滴撞击固体壁面的动力学行为。基于有限元法,通过修正的幂律黏度模型耦合纳米流体的剪切变稀特性,采用水平集方法捕捉相界面的移动,建立纳米流体液滴撞击固体壁面的数值模型。模拟结果与实验结果较好一致,验证了数值模型的正确性与准确性。研究发现实验配制的纳米流体表现出非牛顿剪切变稀特性,纳米颗粒的加入抑制了液滴撞击固体壁面过程中的铺展和回缩行为。随着幂律指数m的减小,液滴撞击固体壁面后的铺展范围变大。随着表面张力的增大,液滴的无量纲直径在铺展阶段无明显变化,但在回缩阶段逐渐减小。
The phenomena of droplet impacting on solid surfaces widely occur in engineering fields such as the power machinery,spray cooling,and coating. The homogeneous and stable nanofluids were prepared by dispersing graphene and MWCNT to epoxy resin using ultrasound technique. The impacting process of droplet on solid surface was investigated by means of high-speed camera technique. Simulations of droplet impacting on surfaces were carried out by employing the finite element scheme. The level-set method was used to capture the interface movement and a modified power-law model was used to characterize the effect of nanoparticle additives. Simulations showed that the results were in reasonably good agreement with the experimental data. The experimental results showed that the nanoparticle additives brought shear-thinning properties to base fluids and suppressed the spreading behaviors of droplet. The simulation results revealed that with the decrease of the power law index m,the range of variation during the droplet spreading process became significantly large. With the increase of the surface tension,there was no significant change in the dimensionless diameter during the spreading phase, while during the receding phase the dimensionless diameter of droplet decreased gradually.
作者
王睿
沈学峰
霍元平
王军锋
郑诺
刘海龙
WANG Rui;SHEN Xuefeng;HUO Yuanping;WANG Junfeng;ZHENG Nuo;LIU Hailong(School of Energy and Power Engineering,Jiangsu University,Zhenjiang 212013,Jiangsu,China)
出处
《中国科学院大学学报（中英文）》
CSCD
北大核心
2020年第2期281-287,共7页
Journal of University of Chinese Academy of Sciences
基金
国家自然科学基金(51876086)
江苏省博士后项目(1401147C)
江苏大学高级人才启动基金(14JDG016)资助。
