Item Details

Effect of Ground Proximity on the Aerodynamic Characteristics of Aspect-Ratio-1 Airfoils With and Without End Plates

by Arthur W. Carter
Format
Book; Government Document; Online; EBook
Published
Washington, [D.C.] : National Aeronautics and Space Administration, 1961.
Language
English
Series
NASA Technical Note
Summary
An investigation has been made to determine the effect of ground proximity on the aerodynamic characteristics of aspect-ratio-1 airfoils. The investigation was made with the model moving over the water in a towing tank in order to eliminate the effects of wind-tunnel walls and of boundary layer on ground boards at small ground clearances. The results indicated that, as the ground was approached, the airfoils experienced an increase in lift-curve slope and a reduction in induced drag thus, lift-drag ratio was increased. As the ground was approached, the profile drag remained essentially constant for each airfoil. Near the ground, the addition of end plates to the airfoil resulted in a large increase in lift-drag ratio. The lift characteristics of the airfoils indicated stability of height at positive angles of attack and instability of height at negative angles; therefore, the operating range of angles of attack would be limited to positive values. At positive angles of attack, the static longitudinal stability was increased as the height above the ground was reduced. Comparison of the experimental data with Wieselsberger's ground-effect theory (NACA Technical Memorandum 77) indicated generally good agreement between experiment and theory for the airfoils without end plates.
Description
27 p. : ill. ; 26 cm.
Mode of access: Internet.
Notes
  • Report Number: L-1693.
  • Document ID: 19980228064 .
  • "NASA TN D-970."
  • "Langley Research Center, Langley Air Force Base, Va."
  • "October 1961."
  • Cover title.
  • Includes bibliographical references (p. 9).
Series Statement
NASA technical note ; D-970
Other Forms
Also available from the NASA Technical Reports Server (http://ntrs.nasa.gov/). Address as of 4/07/07: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980228064_1998388534.pdf.
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Technical Details

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    a| Effect of ground proximity on the aerodynamic characteristics of aspect-ratio-1 airfoils with and without end plates / c| by Arthur W. Carter.
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    a| Washington, [D.C.] : b| National Aeronautics and Space Administration, c| 1961.
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    a| 27 p. : b| ill. ; c| 26 cm.
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    a| NASA technical note ; v| D-970
    500
      
      
    a| Report Number: L-1693.
    500
      
      
    a| Document ID: 19980228064 .
    500
      
      
    a| "NASA TN D-970."
    500
      
      
    a| "Langley Research Center, Langley Air Force Base, Va."
    500
      
      
    a| "October 1961."
    500
      
      
    a| Cover title.
    504
      
      
    a| Includes bibliographical references (p. 9).
    520
      
      
    a| An investigation has been made to determine the effect of ground proximity on the aerodynamic characteristics of aspect-ratio-1 airfoils. The investigation was made with the model moving over the water in a towing tank in order to eliminate the effects of wind-tunnel walls and of boundary layer on ground boards at small ground clearances. The results indicated that, as the ground was approached, the airfoils experienced an increase in lift-curve slope and a reduction in induced drag thus, lift-drag ratio was increased. As the ground was approached, the profile drag remained essentially constant for each airfoil. Near the ground, the addition of end plates to the airfoil resulted in a large increase in lift-drag ratio. The lift characteristics of the airfoils indicated stability of height at positive angles of attack and instability of height at negative angles; therefore, the operating range of angles of attack would be limited to positive values. At positive angles of attack, the static longitudinal stability was increased as the height above the ground was reduced. Comparison of the experimental data with Wieselsberger's ground-effect theory (NACA Technical Memorandum 77) indicated generally good agreement between experiment and theory for the airfoils without end plates.
    530
      
      
    a| Also available from the NASA Technical Reports Server (http://ntrs.nasa.gov/). Address as of 4/07/07: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980228064_1998388534.pdf.
    538
      
      
    a| Mode of access: Internet.
    650
      
    7
    a| Lift drag ratio. 2| nasat
    650
      
    7
    a| Drag reduction. 2| nasat
    650
      
    7
    a| Angle of attack. 2| nasat
    650
      
    7
    a| Boundary layers. 2| nasat
    650
      
    7
    a| Induced drag. 2| nasat
    650
      
    7
    a| Wind tunnel tests. 2| nasat
    650
      
    7
    a| Aspect ratio. 2| nasat
    650
      
    7
    a| End plates. 2| nasat
    650
      
    7
    a| Airfoils. 2| nasat
    650
      
    7
    a| Ground effect(Aerodynamics) 2| nasat
    650
      
    7
    a| Aerodynamic characteristics. 2| nasat
    650
      
    0
    a| Ground-cushion phenomenon.
    710
    1
      
    a| United States. b| National Aeronautics and Space Administration.
    710
    2
      
    a| Langley Research Center.
    974
      
      
    b| UIU c| UIUC d| 20141113 s| google u| uiug.30112106915124 y| 1961 r| pd q| bib

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