Issue 10 Volume 41 May 16, 2003

subsequently solved for the production version of the F/A-l8E/F, a high-level review panel emphasized the poor understanding
of such phenomena and issued a strong recommendation to: Initiate a national research effort to thoroughly and systematically
study the wing drop phenomena. A comprehensive, cooperative NASA/Navy/Air Force AWS Program was designed to
respond to provide the required technology requirements. As part of the AWS Program, a work element was directed at a
historical review of wing-drop experiences in past aircraft development programs at high subsonic and transonic speeds. In
particular, information was requested regarding: specific aircraft configurations that exhibited uncommanded motions and the
nature of the motions; geometric characteristics of the air- planes; flight conditions involved in occurrences; relevant data,
including wind-tunnel, computational, and flight sources; figures of merit used for analyses; and approaches used to alleviate
the problem. An attempt was also made to summarize some of the more important lessons learned from past experiences, and
to recommend specific research efforts. In addition to providing technical information to assist the AWS research objectives,
the study produced fundamental information regarding the historical challenge of uncommanded lateral-directional motions
at transonic conditions and the associated aerodynamic phenomena.
Author
Aerodynamic Stalling; Transonic Speed; Military Aircraft; Aerodynamics
20030032405 NASA Langley Research Center, Hampton, VA, USA
Aerodynamic Drag and Drag Reduction: Energy and Energy Savings (Invited)
Wood, Richard M.; [2003]; 20 pp.; In English; 41st AIAAAerospace Sciences Meeting and Exhibit, 6-9 Jan. 2003, Reno, NV,
USA; Original contains color illustrations
Report No.(s): AIAA Paper 2003-0209; No Copyright; Avail: CASI; A03, Hardcopy
An assessment of the role of fluid dynamic resistance and/or aerodynamic drag and the relationship to energy use in the
USA is presented. Existing data indicates that up to 25\% of the total energy consumed in the USA is used to overcome
aerodynamic drag, 27\% of the total energy used in the USA is consumed by transportation systems, and 60\% of the
transportation energy or 16\% of the total energy consumed in the USA is used to overcome aerodynamic drag in
transportation systems. Drag reduction goals of 50\% are proposed and discussed which if realized would produce a 7.85\%
total energy savings. This energy savings correlates to a yearly cost savings in the $30Billion dollar range.
Author
Aerodynamic Drag; United States; Drag Reduction; Energy Conservation; Energy Consumption; Design Optimization;
Research And Development
20030032412 NASA Langley Research Center, Hampton, VA, USA
Three-Dimensional Effects in Multi-Element High Lift Computations
Rumsey, Christopher L.; LeeReusch, Elizabeth M.; Watson, Ralph D., Elsevi; Computers and Fluids; 2003; ISSN 0045-7930;
Volume 32, pp. 631-657; In English; Original contains black and white illustrations; Copyright; Avail: CASI; A03, Hardcopy
In an effort to discover the causes for disagreement between previous two-dimensional (2-D) computations and nominally
2-D experiment for flow over the three-element McDonnell Douglas 30P-30N airfoil configuration at high lift, a combined
experimental/CFD investigation is described. The experiment explores several different side-wall boundary layer control
venting patterns, documents venting mass flow rates, and looks at corner surface flow patterns. The experimental angle of
attack at maximum lift is found to be sensitive to the side-wall venting pattern: a particular pattern increases the angle of attack
at maximum lift by at least 2 deg. A significant amount of spanwise pressure variation is present at angles of attack near
maximum lift. A CFD study using three-dimensional (3-D) structured-grid computations, which includes the modeling of
side-wall venting, is employed to investigate 3-D effects on the flow. Side-wall suction strength is found to affect the angle
at which maximum lift is predicted. Maximum lift in the CFD is shown to be limited by the growth of an off-body corner flow
vortex and consequent increase in spanwise pressure variation and decrease in circulation. The 3-D computations with and
without wall venting predict similar trends to experiment at low angles of attack, but either stall too early or else overpredict
lift levels near maximum lift by as much as 5\%. Unstructured-grid computations demonstrate that mounting brackets lower
the lift levels near maximum lift conditions.
Author
Computational Fluid Dynamics; Suction; Navier-Stokes Equation; Flow Distribution; Corner Flow; Mass Flow Rate;
Computerized Simulation; Three Dimensional Models
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