Spreading features of droplet on micro-textured surface

JIAO Yun-long; DONG Lei; LIU Xiao-jun; LIU Kun

Volume 17 Issue 4

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JIAO Yun-long, DONG Lei, LIU Xiao-jun, LIU Kun. Spreading features of droplet on micro-textured surface[J]. Journal of Traffic and Transportation Engineering, 2017, 17(4): 98-105.

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JIAO Yun-long, DONG Lei, LIU Xiao-jun, LIU Kun. Spreading features of droplet on micro-textured surface[J]. Journal of Traffic and Transportation Engineering, 2017, 17(4): 98-105.

JIAO Yun-long, DONG Lei, LIU Xiao-jun, LIU Kun. Spreading features of droplet on micro-textured surface[J]. Journal of Traffic and Transportation Engineering, 2017, 17(4): 98-105.

Citation:

JIAO Yun-long, DONG Lei, LIU Xiao-jun, LIU Kun. Spreading features of droplet on micro-textured surface[J]. Journal of Traffic and Transportation Engineering, 2017, 17(4): 98-105.

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Spreading features of droplet on micro-textured surface

1.
Institute of Tribology, Hefei University of Technology, Hefei 230009, Anhui, China
2.
School of Mechanical Engineering, North University of China, Taiyuan 030051, Shanxi, China

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Author Bio:
JIAO Yun-long(1990-), male, doctoral student, +86-551-62901756-2733, jiaoyunlong0823@126.com

LIU Kun(1963-), professor, PhD, +86-551-62901756-2733, liukun@hfut.edu.cn
Received Date: 2017-05-02
Publish Date: 2017-08-25

Abstract

Abstract

The dynamics simulation of droplet spreading process on the different micro-textured surfaces was studied on the basis of Flow-3 D, and the moving mechanism of triple contact line was proposed. The spreading scaling laws of contact line, the spreading velocity and the final spreading radius were used to evaluate the spreading features of droplet on the micro-textured surfaces. Test result shows that droplet on the micro-textured and smooth surfaces meets two corresponding spreading scaling laws respectively. The contact area between solid and liquid increases because of the micro-textures. Because the excess driving force is obtained in the spreading process of droplet, both the spreading velocity and the final spreading radius increase. The final spreading radius on the micro-textured surface with square pits increases from 1.05 mm to 1.30 mm, and the maximum radius on the surface with square bulges is 1.62 mm. Micro-bulge is more beneficial to promote droplet spreading compared with micro-pit. Because of the existence of micro-bulges, the contact area between solid and liquid increases rapidly, the excess driving force is obtained in spreading process of droplet, the micro-channels between micro-bulges form, so the triple contact line keeps continuous feature all the time. While on the textured surface with micro-pits, the triple contact line is pinned in the micro-pits despite of the increase of contact area between solid and liquid, and the droplet eventually stays at the equilibrium position with the decrease of spreading velocity. Moreover, droplet spreading process has anisotropy on the surface with rectangle texture. The flow velocity parallelled to the micro-texture direction is higher, and the final spreading radius is 1.13 mm, which shows a good spreading feature. While the flow velocity vertical to the micro-texture direction is smaller, the spreading radius is 0.94 mm because of the discontinuity of triple contact line, so the spreading feature is poorer.
- automobile engineering,
- micro-texturing lubrication,
- dynamics simulation,
- spreading process,
- triple contact line,
- anisotropy

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References(25)

References

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