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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2017, Vol. 38 ›› Issue (2): 520710-520718.doi: 10.7527/S1000-6893.2016.0278

• Special Column of Aviation Guided Weapons • Previous Articles     Next Articles

Energy dissipation mechanism of droplets impacting superhydrophobic surfaces

LIU Senyun1, SHEN Yizhou1,2, ZHU Chunling1, TAO Jie2, XIE Lei3   

  1. 1. College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
    2. College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
    3. Institute of Environment Controlling and Life Saving, AVIC Aviation Aircraft Co. Ltd. R & D Center, Hanzhong 723213, China
  • Received:2016-08-26 Revised:2016-10-26 Online:2017-02-15 Published:2016-10-27
  • Supported by:

    National Basic Research Program of China (2015CB755800); National Natural Science Foundation of China (11372335); National Postdoctoral Program for Innovative Talents (BX201600073); Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions

Abstract:

Designing superhydrophobic surfaces on the icing locations of aircrafts can greatly reduce the dependence on the traditional high energy-consumption anti/de-icing technologies, so as to improve the fuel efficiency of aircrafts. The aim of the present work is to analyze the energy dissipation mechanism of droplets impacting on the hierarchical superhydrophobic surface based on experiments and numerical simulations. Ti6Al4V as the substrate is sandblasted to construct the microscale rough structure, and then is put in the 1 mol/L NaOH solution to thermally growth a layer of nanowires, obtaining the superhydrophobicity after the modification. The morphologies are observed by field emission scanning electron microscope (FE-SEM), and the two main wetting parameters (apparent contact angle and contact angle hysteresis) on superhydrophobicity are characterized via a dynamic video contact angle meter. Based on the pursuant composite Level set-VOF numerical method of gas-liquid phase interface, the contact process of a droplet impacting superhydrophobic surfaces can be reproduced with a numerical calculation. Experimentally, a high-speed camera is also used to record the moving process of the impacting droplet on the superhydrophobic surface to verify the correctness of the numerical model. Discussion of the energy dissipation during the moving process of the droplet demonstrates that the energy dissipation depends mainly on the dynamic wetting properties of the superhydrophobic surface and the wetting interfacial model.

Key words: superhydrophobic surfaces, impact droplet, numerical simulation, energy dissipation, wetting interfacial model

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