<DOC>
<DOCNO>
206
</DOCNO>
<TITLE>
the applications of the polygon method to the calculation
of the compressible subsonic flow round two-dimensional
profiles .
</TITLE>
<AUTHOR>
woods,l.c.
</AUTHOR>
<BIBLIO>
arc cp115, 1953.
</BIBLIO>
<TEXT>
  this paper sets out the method now used by the author of
applying the polygon method to the calculation of the compressible
subsonic flow round two-dimensional aerofoils .  tables have been
constructed which can be used for all aerofoil shapes, putting the
polygon method on the same footing numerically as goldstein's
method has the advantage over approximation 3 that it can be applied in
the following cases which are beyond the scope of goldstein's method ..
conventional aerofoils, (b) the low-speed flow about very thick
aerofoils, e.g., in reference 3 it is applied to circular cylinders, (c)
the flow about symmetric aerofoils between either straight or constant
pressure walls, (d) flow in asymmetric channels,
and (e) more difficult problems
of the flow about aerofoils in the presence
of one or two constraining
walls (to be published) .  a method of
calculating lift and moment
coefficients, and their rates of change
with incidence (a) is also
given in the paper .
  as an example the velocity distribution and the rates of
change of the lift and moment coefficients with a are calculated for
the aerofoil r.a.e.104 at values of m (mach number at infinity) of 0,
and 0.7, for various values of the incidence, a .  the velocity
distributions for zero incidence are found to be in fair agreement with
the corresponding experimental results .  the results at incidence are
in satisfactory agreement with the experimental results, not for the
same incidence, but for the same lift coefficient .  it is found, for
example, that at m = 0.7 the theory for a = 0.8 agrees best
with experiment for a = 1.0, when the lift coefficients are
approximately the same .
</TEXT>
</DOC>
