국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	WATER TUNNEL FLOW VISUALIZATION STUDY OF A 4.4 PERCENT SCALE X-31 FOREBODY
저자	Brent Cobleigh and John Del Frate
Keyword	Asymmetry; Forebody; High angle of attack; Noseboom; Strake; Vortex flow; Water tunnel; X-31
URL	http://www.dfrc.nasa.gov/DTRS/1994/PDF/H-1997.pdf
보고서번호	NASA-TM-104276
발행년도	1994
출처	NASA Dryden Flight Research Center
ABSTRACT	A water tunnel test of a 4.4 percent-scale, forebody-only model of the X-31 aircraft with different forebody strakes and nosebooms has been performed in the Flow Visualization Facility at the NASA Dryden Flight Research Center. The focus of the study was to determine the relative effects of the different configurations on the stability and symmetry of the high-angle-of-attack forebody vortex flow field. The clean, noseboom-off configuration resisted the development of asymmetries in the primary vortices through 70?angle of attack. The wake of the X-31 flight test noseboom configuration significantly degraded the steadiness of the primary vortex cores and promoted asymmetries. An alternate L-shaped noseboom mounted underneath the forebody had results similar to those seen with the noseboom-off configuration, enabling stable, symmetrical vortices up to 70?angle of attack. The addition of strakes near the radome tip along the waterline increased the primary vortex strength while it simultaneously caused the vortex breakdown location to move forward. Forebody strakes did not appear to significantly reduce the asymmetries in the forebody vortex field in the presence of the flight test noseboom.