Effect of Feather Elasticity of Kingfisher Wing on Droplet Impact Dynamics  

作　　者：Chengchun Zhang Zhengyang Wu Xiumei Zhang Yongli Yue Jing Wang 

机构地区：[1]Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022, China [2]State Key Laboratory of Automotive Simulation and Control, Jilin University, Changehun 130022, China [3]College of Physics, Jilin University, Changchun 130012, China

出　　处：《Journal of Bionic Engineering》2018年第4期731-740,共10页仿生工程学报（英文版）

基　　金：This study was supported by the National Natural Science Foundation of China （Grant Nos. 51575227 and 51706084）, the National Key Research and Develop- ment Program of China （Grant No. 2016YFE0132900）, the Science and Technology Project of Jilin Provincial Education Department （Grant No. JJKH20170795K2）, and the Science and Technology Development Program of Jilin Province （Grant No. 172411GG010040701）.

摘　　要：We experimentally studied droplet impact dynamics onto wing feathers of kingfishers. Distilled water droplets with a fixed diameter of 2.06 mm were used as drop liquid and the initial impact velocities of droplets varied from 0.28 m· s^-1 to 1.60 m·s^-1. Two high-speed cameras were utilized to capture the impact process of water droplets onto the wing feather surface from both horizontal and vertical directions. Two states of the feathers （elastic and inelastic） were considered to study the influence of elasticity. At the entire impact ve- locity range we studied, regular rebound, bubble trapping and jetting, partial pinning and partial rebound of droplets on inelastic wing feather surface were observed as the initial impact velocity increased. However, only one dynamic behavior （regular rebound） was found on the elastic wing feather surface. The elasticity plays a more important role in the direction difference of droplet spreading than wing feather microstructure. The contact time of water droplets on the elastic wing feather surface was less than that on the inelastic surface within the range of Web numbers from 1.06 to 36 under test conditions.We experimentally studied droplet impact dynamics onto wing feathers of kingfishers. Distilled water droplets with a fixed diameter of 2.06 mm were used as drop liquid and the initial impact velocities of droplets varied from 0.28 m· s^-1 to 1.60 m·s^-1. Two high-speed cameras were utilized to capture the impact process of water droplets onto the wing feather surface from both horizontal and vertical directions. Two states of the feathers （elastic and inelastic） were considered to study the influence of elasticity. At the entire impact ve- locity range we studied, regular rebound, bubble trapping and jetting, partial pinning and partial rebound of droplets on inelastic wing feather surface were observed as the initial impact velocity increased. However, only one dynamic behavior （regular rebound） was found on the elastic wing feather surface. The elasticity plays a more important role in the direction difference of droplet spreading than wing feather microstructure. The contact time of water droplets on the elastic wing feather surface was less than that on the inelastic surface within the range of Web numbers from 1.06 to 36 under test conditions.

关 键 词：BIONIC droplet impact kingfisher feather ELASTICITY contact time spreading behavior 

分 类 号：O313[理学—一般力学与力学基础] O343[理学—力学]