본문 바로 가기

로고

국내 최대 기계 및 로봇 연구정보
통합검색 화살표
  • 시편절단기 Mecatome T180
  • 우수 논문

    뷰페이지 제목 게시판 내용

    Effects of superhydrophobic surfaces on the flow around an NACA0012 hydrofoil at low Reynolds numbers  
    Jungjin Lee(Seoul National University)
    Korea | Springer
    2018.06.02 | 바로가기
    Experiments in Fluids
    Cited by 13

    ■  View full text
    Springer, Experiments in Fluids, Published: 02 June 2018 
    https://link.springer.com/article/10.1007/s00348-018-2564-6#citeas

     

    ■  Researchers
    Jungjin Lee, Hyunseok Kim & Hyungmin Park
    Seoul National University

     

    ■  Abstract
    In the present study, the effects of superhydrophobic surface on the flow around an NACA0012 hydrofoil are experimentally investigated at low Reynolds number range of 0.2–1.0 ×104. The velocity fields were measured using two-dimensional digital particle image velocimetry in a water tunnel while varying the angle of attack from 0∘ to 20∘. The spray-coating of hydrophobic nanoparticles was used to create superhydrophobic surfaces. Depending on the Reynolds number and angle of attack, we found that the effects of superhydrophobic surface show up differently, which is determined by the relative strength of turbulence caused by both the surface slip (influence of trapped air pockets) and roughness, compared to that of background (i.e., uncontrolled) flow. In general, the superhydrophobic surface imposes a little influence on the wake behind a hydrofoil when the angle of attack is very low (attached flow) or high (fully separated flow). At intermediate angles of attack (flow separates between the leading and trailing edges), however, it is measured that the flow over superhydrophobic surface has a stronger turbulence, and thus, the enhanced shear-layer instability forces the early vortex rollup in the wake and reduction of vortex formation length. Interestingly, there is a transitional range of angle of attack, in which this effect is reversed, and thus, the vortex rollup is slightly delayed. This trend can be explained based on the changes in the uncontrolled flow structures, and finally, we classify the effects of superhydrophobic surface in terms of Reynolds number and angle of attack, in the considered ranges of both.

    전체댓글0

    댓글 입력란
    프로필 이미지
    0/250자

    서브 사이드

    서브 우측상단1