타원형 실린더에 의해 교란되어진 난류경계층에 관한 실험적 연구

DOI QR코드

DOI QR Code

최재호;조정원;이상준
Choe, Jae-Ho;Jo, Jeong-Won;Lee, Sang-Jun

  • 발행 : 2001.11.01

초록

Turbulent boundary layer over a flat plate was disturbed by installing an elliptic cylinder with an axis ratio of AR=2. For comparison, the same experiment was carried out for a circular cylinder having the same vertical height. The surface pressure and the heat transfer coefficient on the flat plate were measured with varying the gap distance between the elliptic cylinder and the flat plate. The mean velocity and the turbulent intensity profile of the streamwise velocity component were measured using a hot-wire anemometry. As a result, the flow structure and the local heat transfer rate were modified by the interaction between the cylinder wake and the turbulent boundary layer as a function of the critical gap ratio where the regular vortices start to shed. For the elliptic cylinder, the critical gap ratio is increased and the surface pressure on the flat plate is recovered rapidly at downstream location, compared with the equivalent circular cylinder. The maximum heat transfer rate occurs at the gap ratio of G/B = 0.5, where the flow interaction between the lower shear layer of the cylinder wake and the turbulent boundary layer is strong.

키워드

난류경계층;타원형 실린더;임계 틈새비;상호작용

참고문헌

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