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A Study on Turbulence Stimulation Effect of Studs for Boundary Layer Over a Flat Plate

평판 경계층에 대한 스터드의 난류촉진 영향 연구

  • Lee, Joon-Hyoung (Korea Research Institute of Ships and Ocean Engineering) ;
  • Jeong, So-Won (Korea Research Institute of Ships and Ocean Engineering) ;
  • Hwang, Seunghyun (Korea Research Institute of Ships and Ocean Engineering)
  • 이준형 (한국해양과학기술원 부설 선박해양플랜트연구소) ;
  • 정소원 (한국해양과학기술원 부설 선박해양플랜트연구소) ;
  • 황승현 (한국해양과학기술원 부설 선박해양플랜트연구소)
  • Received : 2021.10.27
  • Accepted : 2021.11.23
  • Published : 2022.02.20

Abstract

The turbulence stimulation effect of studs for boundary layer over a flat plate was investigated through the flow measurement in KRISO cavitation tunnel. For the test, Laser Doppler Velocimetry (LDV) and three flat plate models were used: (1) flat plate without studs; (2) flat plate with one stud row; (3) flat plate with two stud rows. The dimension and location of stud rows and the inflow speed were selected considering test conditions for standard-sized model ships in KRISO towing tank. The boundary layer characteristics of test models were analyzed and compared in terms of mean velocity profiles, turbulence intensity profiles, boundary layer thickness, and shape factor. In the case of the flat plate without studs, transition from laminar to turbulent flow occurred around Rex=3.83 ~ 5.19 × 105. In the case of flat plates with stud rows, the flow rapidly changed into turbulent flow right after passing the first stud row. In the state where turbulence was already developed, the second stud row slightly increased the turbulence intensity near the top of the stud, but did not significantly affect the boundary layer characteristics such as mean velocity distribution, boundary layer thickness, and shape factor.

Keywords

Acknowledgement

본 연구는 선박해양플랜트연구소의 주요사업인 "첨단운송체의 항내 운항성능향상을 위한 축척효과를 고려한 운항제어원천기술 개발(3/5)"에 의해 수행되었습니다 (PES3860).

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