TITLE : GROUND-EFFECT STUDY OF THE HARRIER VERTICAL/SHORT TAKE-OFF AND LANDING (V/STOL) AIRCRAFT

BY : CHAM Consultancy Team - E N Jal and D R Glynn British Aerospace Defence Ltd. - C M Milford

FOR : British Aerospace Defence Ltd., Farnborough Aerospace Centre Hampshire, Hants GU14 6YU

DETAILS :

• Three-Dimensional steady flow
• Cartesian grid, with aircraft shape represented by porosity

NOTES :

• Ground proximity creates an upward jet ("fountain sheet") and a radial spreading jet along the ground surface ("ground sheet").
• These secondary flows can generate an induced downforce which can seriously affect net lift.
• This lift loss can be offset by the use of CADs (Cushion Augmentation Devices) and LIDs (Lift Improvement Devices)

  The pictures (courtesy of British Aerospace Defence Ltd.) are as follows:

  1. FRONT FACING VIEW (showing the propulsion jets) at 3 feet above ground The impact of these jets on the ground surface creates the upward central "fountain" jet and radial ground "sheet" jet.
  Vector Flowfield : Front Facing View at 3 Feet above ground
  2. SIDE FACING VIEW at 3 feet above the ground.
  Flowfield : Side Facing View at 3 Feet above ground
  3. AUTOPLOT plot file of comparison for predicted induced vertical drag (downforce) with experimental data.
  Comparison with measurements

  
  Full information about the PHOENICS calculation can be found in :- The use of PHOENICS in external V/STOL aerodynamics PHOENICS Journal - 1991 Vol. 4, Suppl. 1, pp 43-55

  For information about British Aerospace Defence Ltd., write to :-

  Mr Peter Curtis British Aerospace Defence Ltd. Tel : 0252 - 373232 Fax : 0252 - 382270

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