中国物理B ›› 2013, Vol. 22 ›› Issue (8): 84702-084702.doi: 10.1088/1674-1056/22/8/084702

• ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS • 上一篇    下一篇

Droplet impact on regular micro-grooved surfaces

胡海豹, 黄苏和, 陈立斌   

  1. College of Marine, Northwestern Polytechnical University, Xi'an 710072, China
  • 收稿日期:2013-01-19 修回日期:2013-04-20 出版日期:2013-06-27 发布日期:2013-06-27
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 51109178) and the Science and Technology Innovation Foundation of Northwestern Polytechnical University, China (Grant No. JC20120218).

Droplet impact on regular micro-grooved surfaces

Hu Hai-Bao (胡海豹), Huang Su-He (黄苏和), Chen Li-Bin (陈立斌)   

  1. College of Marine, Northwestern Polytechnical University, Xi'an 710072, China
  • Received:2013-01-19 Revised:2013-04-20 Online:2013-06-27 Published:2013-06-27
  • Contact: Hu Hai-Bao E-mail:huhaibao@nwpu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 51109178) and the Science and Technology Innovation Foundation of Northwestern Polytechnical University, China (Grant No. JC20120218).

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摘要： We have investigated experimentally the process of a droplet impact on a regular micro-grooved surface. The target surfaces are patterned such that micro-scale spokes radiate from the center, concentric circles, and parallel lines on the polishing copper plate, using Quasi-LIGA molding technology. The dynamic behavior of water droplets impacting on these structured surfaces is examined using a high-speed camera, including the drop impact processes, the maximum spreading diameters, and the lengths and numbers of fingers at different values of Weber number. Experimental results validate that the spreading processes are arrested on all target surfaces at low velocity. Also, the experimental results at higher impact velocity demonstrate that the spreading process is conducted on the surface parallel to the micro-grooves, but is arrested in the direction perpendicular to the micro-grooves. Besides, the lengths of fingers increase observably, even when they are ejected out as tiny droplets along the groove direction, at the same time the drop recoil velocity is reduced by micro-grooves which are parallel to the spreading direction, but not by micro-grooves which are vertical to the spreading direction.

关键词: micro-groove, droplet, drop impact, spreading, fingers

Abstract: We have investigated experimentally the process of a droplet impact on a regular micro-grooved surface. The target surfaces are patterned such that micro-scale spokes radiate from the center, concentric circles, and parallel lines on the polishing copper plate, using Quasi-LIGA molding technology. The dynamic behavior of water droplets impacting on these structured surfaces is examined using a high-speed camera, including the drop impact processes, the maximum spreading diameters, and the lengths and numbers of fingers at different values of Weber number. Experimental results validate that the spreading processes are arrested on all target surfaces at low velocity. Also, the experimental results at higher impact velocity demonstrate that the spreading process is conducted on the surface parallel to the micro-grooves, but is arrested in the direction perpendicular to the micro-grooves. Besides, the lengths of fingers increase observably, even when they are ejected out as tiny droplets along the groove direction, at the same time the drop recoil velocity is reduced by micro-grooves which are parallel to the spreading direction, but not by micro-grooves which are vertical to the spreading direction.

Key words: micro-groove, droplet, drop impact, spreading, fingers

中图分类号: 

  • 47.55.Dz
47.54.De (Experimental aspects) 61.30.Pq (Microconfined liquid crystals: droplets, cylinders, randomly confined liquid crystals, polymer dispersed liquid crystals, and porous systems)