국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	REYNOLDS NUMBER EFFECTS AT HIGH ANGLES OF ATTACK
저자	David F. Fisher, Brent R. Cobleigh, Daniel W. Banks, Robert M. Hall and Richard W. Wahls
Keyword	Angle of attack; Flight test; Forebody; Noseboom; Reynolds number; Vortices;
URL	http://www.dfrc.nasa.gov/DTRS/1998/PDF/H-2255.pdf
보고서번호	NASA-TP-1998-206553
발행년도	1998
출처	NASA Dryden Flight Research Center
ABSTRACT	Lessons learned from comparisons between ground-based tests and flight measurements for the high-angle-of- attack programs on the F-18 High Alpha Research Vehicle (HARV), the X-29 forward-swept wing aircraft, and the X-31 enhanced fighter maneuverability aircraft are presented. On all three vehicles, Reynolds number effects were evident on the forebodies at high angles of attack. The correlation between flight and wind tunnel forebody pressure distributions for the F-18 HARV were improved by using twin longitudinal grit strips on the forebody of the wind-tunnel model. Pressure distributions obtained on the X-29 wind-tunnel model at flight Reynolds numbers showed excellent correlation with the flight data up to alpha = 50 deg. Above alpha = 50 deg the pressure distributions for both flight and wind tunnel became asymmetric and showed poorer agreement, possibly because of the different surface finish of the model and aircraft. The detrimental effect of a very sharp nose apex was demonstrated on the X-31 aircraft. Grit strips on the forebody of the X-31 reduced the randomness but increased the magnitude of the asymmetry. Nose strakes were required to reduce the forebody yawing moment asymmetries and the grit strips on the flight test noseboom improved the aircraft handling qualities.