<DOC>
<DOCNO>
245
</DOCNO>
<TITLE>
the ground effect on the jet flap in two dimensions .
</TITLE>
<AUTHOR>
huggett,d.j.
</AUTHOR>
<BIBLIO>
arc 19,713, 1957.
</BIBLIO>
<TEXT>
  this paper presents the results of the first part of an
experimental investigation of the ground effect on simple jet flap
aerofoils .  in this part of the work an aerofoil having a 58.1 deg jet
flap was tested under two-dimensional conditions .
  the pressure lift on the aerofoil was measured, with the ground
at fixed positions, for varying jet momentum coefficients .  it was
found that the effect of the ground on the pressure lift was very small
up to a certain critical jet coefficient .  on increasing the jet
coefficient beyond the critical value a marked loss of pressure lift was
observed .  this critical value referred to is approximately the same as
the jet coefficient at which the jet first hits the ground .
  some significant, though highly tentative comments, are made
regarding the practical application of this work to the take-off
characteristics of a jet flapped aircraft .
</TEXT>
</DOC>
