인문학
사회과학
자연과학
공학
의약학
농수해양학
예술체육학
복합학
지원사업
학술연구/단체지원/교육 등 연구자 활동을 지속하도록 DBpia가 지원하고 있어요.
커뮤니티
연구자들이 자신의 연구와 전문성을 널리 알리고, 새로운 협력의 기회를 만들 수 있는 네트워킹 공간이에요.
초록·키워드
This work aimed to investigate the boundary layer topology over various densities of roughness. For experiments, we used three different surface conditions comprised of rectangular elements with uniform height arranged in staggered rows and covered the entire floor of the wind tunnel. The frontal and plan solidity for each case changed, λ f from 0.3 to 1.2 and λ p from 1.3 to 4.7, respectively. Also, we used one more surface, without roughness, for comparison. During the experiment, the position of measuring cross-sections varied relative to the inlet, while the free flow velocity was 5 m·s -1 . Thus, the corresponding Reynolds number Re τ was from 300 to 1500 (based on boundary layer thickness δ and friction velocity u τ ) or Re θ was from 400 to 5500 (based on momentum thickness). To determine the boundary layer topology in streamwise directions, we used a 55P14 miniature hot-wire probe. The obtained data allowed us to estimate patterns of distribution mean velocity profile, streamwise Reynolds stress, and turbulence intensity for different surface cases. In addition, an analysis of the scales of the turbulent flow over different surface types was also carried out. Namely, the integral length scale, Taylor microscale, and dissipation scale were determined. Obtained results show that roughness density composition strongly affects boundary layer characteristics. The obtained results also represent a correlation between the Taylor microscale and the initial position of the log region.
인공지능 문자 인식 모델을 통해 추출된 텍스트로, 일부 오타나 오류가 포함될 수 있으나 지속적으로 개선 중입니다.
오류를 발견하셨다면 해당 부분을 드래그한 후 ' 를 통해 신고해주세요.
오류를 발견하셨다면 해당 부분을 드래그한 후 ' 를 통해 신고해주세요.