› › Low Speed Longitudinal Aerodynamic Characteristics Through Poststall For 21 Novel Planform Shapes

Low-Speed Longitudinal Aerodynamic Characteristics Through Poststall for 21 Novel Planform Shapes

Author : National Aeronautics and Space Administration (NASA)

Publisher : Createspace Independent Publishing Platform

Page : 118 pages

File Size : 42,22 MB

Release : 2018-07-18

Category :

ISBN : 9781723196560

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Book Description

To identify planform characteristics which have promise for a highly maneuverable vehicle, an investigation was conducted in the Langley Subsonic Basic Research Tunnel to determine the low-speed longitudinal aerodynamics of 21 planform geometries. Concepts studied included twin bodies, double wings, cutout wings, and serrated forebodies. The planform models tested were all 1/4-in.-thick flat plates with beveled edges on the lower surface to ensure uniform flow separation at angle of attack. A 1.0-in.-diameter cylindrical metric body with a hemispherical nose was used to house the six-component strain gauge balance for each configuration. Aerodynamic force and moment data were obtained across an angle-of-attack range of 0 to 70 deg with zero sideslip at a free-stream dynamic pressure of 30 psf. Surface flow visualization studies were also conducted on selected configurations using fluorescent minitufts. Results from the investigation indicate that a cutout wing planform can improve lift characteristics; however, cutout size, shape, and position and wing leading-edge sweep will all influence the effectiveness of the cutout configuration. Tests of serrated forebodies identified this concept as an extremely effective means of improving configuration lift characteristics; increases of up to 25 percent in the value of maximum lift coefficient were obtained. Gatlin, Gregory M. and Mcgrath, Brian E. Langley Research Center AERODYNAMIC CHARACTERISTICS; ANGLE OF ATTACK; FLOW VISUALIZATION; FOREBODIES; HIGHLY MANEUVERABLE AIRCRAFT; LIFT; LOW ASPECT RATIO WINGS; LOW SPEED; PITCHING MOMENTS; SWEPT WINGS; WIND TUNNEL TESTS; WING PLANFORMS; AERODYNAMIC COEFFICIENTS; ARROW WINGS; BOUNDARY LAYER SEPARATION; DELTA WINGS; DUAL WING CONFIGURATIONS; LEADING EDGE SWEEP; OPENINGS; STRAIN GAGE BALANCES; TRAILING EDGES; UNIFORM FLOW...





Flight Dynamics

Author : Robert F. Stengel

Publisher : Princeton University Press

Page : 864 pages

File Size : 45,88 MB

Release : 2015-01-27

Category : Science

ISBN : 1400866812

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Book Description

Flight Dynamics takes a new approach to the science and mathematics of aircraft flight, unifying principles of aeronautics with contemporary systems analysis. While presenting traditional material that is critical to understanding aircraft motions, it does so in the context of modern computational tools and multivariable methods. Robert Stengel devotes particular attention to models and techniques that are appropriate for analysis, simulation, evaluation of flying qualities, and control system design. He establishes bridges to classical analysis and results, and explores new territory that was treated only inferentially in earlier books. This book combines a highly accessible style of presentation with contents that will appeal to graduate students and to professionals already familiar with basic flight dynamics. Dynamic analysis has changed dramatically in recent decades, with the introduction of powerful personal computers and scientific programming languages. Analysis programs have become so pervasive that it can be assumed that all students and practicing engineers working on aircraft flight dynamics have access to them. Therefore, this book presents the principles, derivations, and equations of flight dynamics with frequent reference to MATLAB functions and examples. By using common notation and not assuming a strong background in aeronautics, Flight Dynamics will engage a wide variety of readers. Introductions to aerodynamics, propulsion, structures, flying qualities, flight control, and the atmospheric and gravitational environment accompany the development of the aircraft's dynamic equations.



Low-Speed Longitudinal Aerodynamic Characteristics of a Flat-Plate Planform Model of an Advanced Fighter Configuration

Author : National Aeronautics and Space Administration (NASA)

Publisher : Createspace Independent Publishing Platform

Page : 46 pages

File Size : 12,60 MB

Release : 2018-07-05

Category :

ISBN : 9781722349769

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Book Description

A flat-plate wind tunnel model of an advanced fighter configuration was tested in the NASA LaRC Subsonic Basic Research Tunnel and the 16- by 24-inch Water Tunnel. The test objectives were to obtain and evaluate the low-speed longitudinal aerodynamic characteristics of a candidate configuration for the integration of several new innovative wing designs. The flat plate test allowed for the initial evaluation of the candidate planform and was designated as the baseline planform for the innovative wing design study. Low-speed longitudinal aerodynamic data were obtained over a range of freestream dynamic pressures from 7.5 psf to 30 psf (M = 0.07 to M = 0.14) and angles-of-attack from 0 to 40 deg. The aerodynamic data are presented in coefficient form for the lift, induced drag, and pitching moment. Flow-visualization results obtained were photographs of the flow pattern over the flat plate model in the water tunnel for angles-of-attack from 10 to 40 deg. The force and moment coefficients and the flow-visualization photographs showed the linear and nonlinear aerodynamic characteristics due to attached flow and vortical flow over the flat plate model. Comparison between experiment and linear theory showed good agreement for the lift and induced drag; however, the agreement was poor for the pitching moment. Mcgrath, Brian E. and Neuhart, Dan H. and Gatlin, Gregory M. and Oneil, Pat Langley Research Center RTOP 505-68-70-05...