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Numerical simulation of the flow about the F-18 HARV at high angle of attackThis report summarizes research done over the past two years as part of NASA Grant NCC 2-729. This research has been aimed at validating numerical methods for computing the flow about the complete F-18 HARV at alpha = 30 deg and alpha = 45 deg. At 30 deg angle of attack, the flow about the F-18 is dominated by the formation, and subsequent breakdown, of strong vortices over the wing leading-edge extensions (LEX). As the angle of attack is increased to alpha = 45 deg, the fuselage forebody of the F-18 contains significant laminar and transitional regions which are not present at alpha = 30 deg. Further, the flow over the LEX at alpha = 45 deg is dominated by an unsteady shedding in time, rather than strong coherent vortices. This complex physics, combined with the complex geometry of a full aircraft configuration, provides a challenge for current computational fluid dynamics (CFD) techniques. The following sections present the numerical method and grid generation scheme that was used, a review of prior research done to numerically model the F-18 HARV, and a discussion of the current research. The current research is broken into two main topics: the effect of engine-inlet mass-flow rate on the F-18 vortex breakdown position, and the results using a refined F-18 computational model to compute the flow at alpha = 30 deg and alpha = 45 deg.
Document ID
19950004527
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Murman, Scott M.
(MCAT Inst. Moffett Field, CA., United States)
Date Acquired
September 6, 2013
Publication Date
July 1, 1994
Subject Category
Aerodynamics
Report/Patent Number
NASA-CR-196396
NAS 1.26:196396
MCAT-94-11
Accession Number
95N10940
Funding Number(s)
CONTRACT_GRANT: NCC2-729
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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