[논문]Unsteady Aerodynamic Characteristics depending on Reduced Frequency for a Pitching NACA0012 Airfoil at Rec=2.3×104

Kim, Dong-Ha; Chang, Jo-Won; Sohn, Myong Hwan

doi:10.5139/ijass.2017.18.1.8

Unsteady Aerodynamic Characteristics depending on Reduced Frequency for a Pitching NACA0012 Airfoil at Rec=2.3×104 원문보기

International journal of aeronautical and space sciences, v.18 no.1, 2017년, pp.8 - 16

Kim, Dong-Ha (Korean Air R&D Center) , Chang, Jo-Won (Department of Aeronautical Science and Flight Operations, Korea Aerospace University) , Sohn, Myong Hwan (Department of Aerospace and Mechanical Engineering, Cheongju University)

Abstract ▼ AI-Helper

Most of small air vehicles with moving wing fly at low Reynolds number condition and the reduced frequency of the moving wing ranges from 0.0 to 1.0. The physical phenomena over the wing dramatically vary with the reduced frequency. This study examines experimentally the effect of the reduced frequency at low Reynolds number. The NACA0012 airfoil performs sinusoidal pitching motion with respect to the quarter chord with the four reduced frequencies of 0.1, 0.2, 0.4 and 0.76 at the Reynolds number $2.3{\times}10^4$. Smoke-wire flow visualization, unsteady surface pressure measurement, and unsteady force calculation are conducted. At the reduced frequency of 0.1 and 0.2, various boundary layer events such as reverse flow, discrete vortices, separation and reattachment change the amplitude and the rotation direction of the unsteady force hysteresis. However, the boundary layer events abruptly disappear at the reduced frequency of 0.4 and 0.76. Especially at the reduced frequency of 0.76, the local variation of the unsteady force with respect to the angle of attack completely vanishes. These results lead us to the conclusion that the unsteady aerodynamic characteristics of the reduced frequency of 0.2 and 0.4 are clearly distinguishable and the unsteady aerodynamic characteristics below the reduced frequency of 0.2 are governed by the boundary layer events.

주제어

AI 본문요약
AI-Helper

* AI 자동 식별 결과로 적합하지 않은 문장이 있을 수 있으니, 이용에 유의하시기 바랍니다.

제안 방법

3×10⁴. Smoke-wire visualization and unsteady pressure measurement were conducted and the unsteady force was calculated from the pressure distribution measured.
All of these previous studies show that aerodynamic characteristics at the low Reynolds number range is complicated and more efforts are necessary to clarify many ambiguous phenomena of the unsteady aerodynamic characteristics at the low Reynolds number range and apply them to practical problems. This study examines experimentally the effect of the reduced frequency at low Reynolds number. The NACA0012 airfoil performs sinusoidal pitching motion with respect to the quarter chord with the four reduced frequencies of 0.

대상 데이터

The airfoil was pitched at the quarter chord with an oscillating AOA of α(t)=0°± 6°sin(ωt). For the flow visualization, a Teikoku alloy wire with a diameter of 0.14 mm and six 1 kW halogen lamps were used. The wire was installed at 3 mm downstream from the trailing edge.
The experiment was conducted in the low-speed wind tunnel with a test section size of 0.5 m (H) × 0.5 m (W) × 1.4 m (L).

참고문헌 (22)

McAlister, K. W. and Carr, L. W., "Water Tunnel Visualizations of Dynamic Stall", Journal of Fluids Engineering, Vol. 101, 1979, pp. 376-380.

상세보기
Ohmi, K., Coutanceau, M., Daube, O. and Loc, T. P., "Further Experiments on Vortex Formation Around an Oscillating and Translating Airfoil at Large Incidences", Journal of Fluid Mechanics, Vol. 255, 1991, pp. 607-630.
Carr, L. W., "Progress in Analysis and Prediction of Dynamic Stall", Journal of Aircraft, Vol. 25, 1988, pp. 6-17.

상세보기
Chang, J. W. and Eun, H. B., "Reduced Frequency Effects on the Near-Wake of an Oscillating Elliptic Airfoil", Journal of Mechanical Science Technology, Vol. 17, 2003, pp. 1234-1245.
Ericsson, L. E., "Moving Wall Effect in Relation to Other Dynamic Stall Flow Mechanics", Journal of Aircraft, Vol. 31, 1994, pp. 1303-1309.

상세보기
Kim, D. H. and Chang, J. W., "Unsteady Boundary Layer for a Pitching Airfoil at Low Reynolds Numbers", Journal of Mechanical Science Technology, Vol. 24, 2010, pp. 429-440.

원문보기 상세보기
Kim, D. H. and Chang, J. W., "Low-Reynolds-Number Effect on Aerodynamic Characteristics of a Pitching NACA0012 Airfoil", Aerospace Science Technology, Vol. 32, 2014, pp. 162-168.

상세보기
Kim, D. H. Chang, J. W. and Kim, H. B., "Aerodynamic Characteristics of a Pitching Airfoil through Pressure- Distortion Correction in Pneumatic Tubing", Journal of Aircraft, Vol. 50, 2013, pp. 590-598.

상세보기
Koochesfahani, M. M., "Vortical Patterns in the Wake of an Oscillating Airfoil", AIAA Journal, Vol. 27, 1989, pp. 1200-1205.

상세보기
Bratt, J. B., "Flow Patterns in the Wake of an Oscillating Airfoil", Aeronautical Research Council, R&M 2773, 1953.
Katz, J. and Weihs, D., "Behavior of Vortex Wakes from Oscillating Airfoils", Journal of Aircraft, Vol. 15, 1978, pp. 861- 863.

상세보기
Kim, J. S. and Park, S. O., "Smoke Wire Visualization of Unsteady Separation over an Oscillating Airfoil", AIAA Journal, Vol. 26, 1988, pp. 1408-1410.

상세보기
Ho, S., Nassef, H., Pornsinsirirak, N., Tai, Y. C. and Ho, C. M., "Unsteady Aerodynamics and Flow Control for Flapping Wing Flyers", Progress in Aerospace Sciences, Vol. 39, 2003, pp. 635-681.

상세보기
Muller, T. J., "Fixed and Flapping Wing Aerodynamics for Micro Air Vehicle Applications", Progress in Astronautics and Aeronautics Series, 2001, pp. 586.
Kim, D. H., Chang, J. W. and Chung, J., "Low Reynolds Number Effect on the Aerodynamic Characteristic of a NACA 0012 Airfoil", Journal of Aircraft, Vol. 48, 2011, pp. 1212-1215.

상세보기
Laitone, E. V., "Wind Tunnel Tests of Wings at Reynolds Numbers Below 70000", Experiments in Fluids, Vol. 23, 1997, pp. 405-409.

상세보기
AIAA, "Assessment of Wind Tunnel Data Uncertainty", AIAA Standard S-071-1995, 1995.
Kim, D. H., Yang, J. H., Chang, J. W. and Chung, J., "Boundary Layer and Near-wake Measurements of NACA 0012 Airfoil at Low Reynolds Numbers", AIAA 2009-1472, 2009.
Brendel, M. and Muller, T. J., "Boundary-layer Measurements on an Airfoil at Low Reynolds Number", Journal of Aircraft, Vol. 25, 1987, pp. 612-617.
Theodorsen, R., "General Theory of Aerodynamic Instability and the Mechanism of Flutter", NACA report-496, 1935.
Garrick, I. E., "Propulsion of a Flapping and Oscillating Airfoil", NACA report-567, 1937.
Leishman, J. G., Principles of helicopter aerodynamics, Cambridge University Press, 2006.

내보내기 구분	파일저장 인쇄 메일전송
구성항목	기본정보 상세정보 관리번호, 논문명, 저널/프로시딩명, 저자 , 발행년, 권, 호, 시작페이지, 끝페이지, 발행기관 관리번호, 논문명, 대등논문명, 저자 , 저널/프로시딩명, 발행기관, 발행년, 발행언어, 권, 호, 시작페이지, 끝페이지, ISBN, ISSN, 주제분야, 키워드, 초록(한글), 초록(영문), 저자(소속기관)
저장형식	Text(ASCII format) Excel format RefWorks Direct Export RIS format (for Reference Manager, ProCite, EndNote), Scholar's Aids, Mendeley
메일정보	받는사람 (필수) @ 보내는사람 (선택) @ 제목 내용 KISTI 검색결과 이메일 서비스
안내	총 건의 자료가 검색되었습니다. 다운받으실 자료의 인덱스를 입력하세요. (1-10,000) 검색결과의 순서대로 최대 10,000건 까지 다운로드가 가능합니다. 데이타가 많을 경우 속도가 느려질 수 있습니다.(최대 2~3분 소요) 다운로드 파일은 UTF-8 형태로 저장됩니다. 파일의 내용이 제대로 보이지 않을실 때는 웹브라우저 상단의 보기 -> 인코딩 -> 자동선택 여부를 확인하십시오. ~ Text(ASCII format) Excel format

연합인증

Unsteady Aerodynamic Characteristics depending on Reduced Frequency for a Pitching NACA0012 Airfoil at Rec=2.3×104 원문보기

Abstract ▼ AI-Helper

주제어

AI 본문요약
AI-Helper

제안 방법

대상 데이터

참고문헌 (22)

이 논문을 인용한 문헌

저자의 다른 논문 :

관련 콘텐츠

원문 보기

원문 URL 링크

오픈액세스(OA) 유형

이 논문과 함께 이용한 콘텐츠

AI-Helper ※ AI-Helper는 오픈소스 모델을 사용합니다.

선택된 텍스트

연합인증

Unsteady Aerodynamic Characteristics depending on Reduced Frequency for a Pitching NACA0012 Airfoil at Rec=2.3×104 원문보기

Abstract ▼ AI-Helper

주제어

AI 본문요약 엑셀 다운로드 AI-Helper

제안 방법

대상 데이터

참고문헌 (22)

이 논문을 인용한 문헌

저자의 다른 논문 :

장조원 (44)

관련 콘텐츠

원문 보기

원문 URL 링크

오픈액세스(OA) 유형

이 논문과 함께 이용한 콘텐츠

AI-Helper ※ AI-Helper는 오픈소스 모델을 사용합니다.

선택된 텍스트

AI 본문요약
AI-Helper